What Does the EIGRP DUAL-3-SIA Error Message Mean?
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008010f016.shtml
PDF:
http://www.cisco.com/warp/public/103/18.pdf
What Does the EIGRP DUAL-3-SIA Error Message Mean?
Reply
Category Archives: 项目案例
Redistributing Between Classful and Classless Protocols: EIGRP or OSPF into RIP or IGRP
In the network diagram for this problem, Router GW-2 is redistributing between RIP and OSPF. The OSPF domain has a different mask (longer in this case) than the RIP domain, and they are on the same major network. Therefore, RIP will not advertise routes learned from OSPF and redistributed into RIP.
更多及解决方法http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093fd9.shtml
原因:http://www.mycisco.cn/post/154.html
[原创]巧用PBR实现不同网段走不同ISP,且互备实验（一个不算完美的解决方法）
上次试验没有完全成功，因为默认路由的问题导致ROUTE-MAP匹配有时会错乱。详细描述见：http://www.mycisco.cn/post/150.html
这次试验利用了PBR，来控制精确的选择出口.思路：
利用PBR优先使用第一个可用接口，给每个PBR故意设置不同顺序
配置：
hostname r4
!
!
ip subnet-zero
!
!
!
!
!
!
interface Ethernet0/0
ip address 192.168.1.4 255.255.255.0
ip nat inside
ip policy route-map isp1-nextif
half-duplex
!
interface Ethernet0/1
ip address 192.168.2.4 255.255.255.0
ip nat inside
ip policy route-map isp2-nextif
half-duplex!
interface Ethernet0/2
no ip address
shutdown
half-duplex
!
interface Ethernet0/3
no ip address
shutdown
half-duplex
!
interface Serial1/0
ip address 10.0.0.1 255.255.255.0
no shu
ip nat outside
serial restart-delay 0
!
interface Serial1/1
ip address 20.0.0.1 255.255.255.0
no shu
ip nat outside
serial restart-delay 0
!
interface Serial1/2
no ip address
shutdown
serial restart-delay 0
!
interface Serial1/3
no ip address
shutdown
serial restart-delay 0
!
ip nat pool isp1 10.0.0.1 10.0.0.1 prefix-length 24
ip nat pool isp2 20.0.0.1 20.0.0.1 prefix-length 24
ip nat inside source route-map toisp1 pool isp1 overload
ip nat inside source route-map toisp1-2 pool isp2 overload
ip nat inside source route-map toisp2 pool isp2 overload
ip nat inside source route-map toisp2-1 pool isp1 overload
！这里需要注意，试验证明采用POOL时候，工作起来不是很正常
当我关闭ISP1所连的S1/0接口后
这个时候1网段的应该走ISP2接口，调试表明确实走了ISP2那个口
但是
这个时候NAT表里只容许1网段的转成ISP2的地址
2网段的数据包 报NAT失败 包被丢弃
NAT配置中将POOL改成使用接口，则无此问题
所以这里不要使用地址池，只能使用接口做NAT。
ip classless
ip route 0.0.0.0 0.0.0.0 10.0.0.3
ip route 0.0.0.0 0.0.0.0 20.0.0.5
！这个默认路由已经可以省略了，PBR优先于它。
ip http server
!
access-list 100 permit ip 192.168.1.0 0.0.0.255 any
access-list 101 permit ip 192.168.2.0 0.0.0.255 any
route-map toisp1 permit 10
match ip address 100
match interface Serial1/0
!
route-map toisp2 permit 10
match ip address 101
match interface Serial1/1
!
route-map toisp1-2 permit 10
match ip address 100
match interface Serial1/1
!
route-map toisp2-1 permit 10
match ip address 101
match interface Serial1/0
!
route-map isp2-nextif permit 10
match ip address 101
set interface s1/0 s1/1
!
route-map isp1-nextif permit 10
match ip address 100
set interface s1/1 s1/0
!利用PBR优先使用第一个可用接口的特性
!
!
!
line con 0
logging synchronous
line aux 0
line vty 0 4
login
!
end
测试中没发现其他什么问题，如有问题请留言，感谢。
[原创]巧用route-map顺序实现不同网段走不同ISP,且互备实验,问题源自91lab论坛网友提问
问题源自91LAB论坛上一位网友的提问,自己就作了这个试验.转载请写明来源http://www.mycisco.cn.谢谢.
此实验存在一个问题,即2条静态路由无效有效控制选路.正因为静态路由的问题导致了route-map匹配有时不按照期望的那样去匹配.看这个实验,权当是进行排错了.如果能准确找到错误原因和原理也不枉花费的时间…….
这个地址是一个解决方法http://www.mycisco.cn/post/152.html
不过最好看完这个有问题的试验，再看上面的地址比较容易明白
r4#sh run
Building configuration…
Current configuration : 1639 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname r4
!
!
ip subnet-zero
!
!
!
!
!
!
interface Loopback0
ip address 4.4.4.4 255.255.255.0
!
interface Ethernet0/0
ip address 192.168.1.4 255.255.255.0
ip nat inside
half-duplex
!
interface Ethernet0/1
ip address 192.168.2.4 255.255.255.0
ip nat inside
half-duplex
!
interface Ethernet0/2
no ip address
shutdown
half-duplex
!
interface Ethernet0/3
no ip address
shutdown
half-duplex
!
interface Serial1/0
ip address 10.0.0.1 255.255.255.0
ip nat outside
shutdown
serial restart-delay 0
!
interface Serial1/1
ip address 20.0.0.1 255.255.255.0
ip nat outside
serial restart-delay 0
!
interface Serial1/2
no ip address
shutdown
serial restart-delay 0
!
interface Serial1/3
no ip address
shutdown
serial restart-delay 0
!
ip nat pool isp1 10.0.0.1 10.0.0.1 prefix-length 24
ip nat pool isp2 20.0.0.1 20.0.0.1 prefix-length 24
ip nat inside source route-map toisp1 pool isp1 overload
ip nat inside source route-map toisp2 pool isp2 overload
ip classless
ip route 0.0.0.0 0.0.0.0 10.0.0.3
ip route 0.0.0.0 0.0.0.0 20.0.0.5
ip http server
!
access-list 100 permit ip 192.168.1.0 0.0.0.255 any
access-list 101 permit ip 192.168.2.0 0.0.0.255 any
route-map toisp1 permit 10
match ip address 100
match interface Serial1/0
!
route-map toisp2 permit 10
match ip address 101
match interface Serial1/1
!
!
line con 0
logging synchronous
line aux 0
line vty 0 4
!
end
============以上是原始配置From:http://www.mycisco.cn 纳米========
实现192.168.1.0/24网段走ISP1 被转成10.0.0.1
实现192.168.2.0/24网段走ISP2 被转成20.0.0.1
但存在一个问题，即当S0/1或S0/2 down掉后，NAT就失败了，因为不符合ROUTE-MAP的条件了，见测试：
（关掉了S1/0）
r4#ping
Protocol [ip]:
Target IP address: 10.10.10.10
Repeat count [5]:
Datagram size [100]:
Timeout in seconds [2]:
Extended commands [n]: y
Source address or interface: 192.168.1.4
Type of service [0]:
Set DF bit in IP header? [no]:
Validate reply data? [no]:
Data pattern [0xABCD]:
Loose, Strict, Record, Timestamp, Verbose[none]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.10.10.10, timeout is 2 seconds:
Packet sent with a source address of 192.168.1.4
…..
Success rate is 0 percent (0/5)
r4#sh ip nat translations 为空，没有发生转换。
=======
上面没有实现一个ISP接口坏掉，另一个顶上。
于是想了一个这样的方法，给每个网段再配一个ROUTE-MAP：还匹配原来的ACL，但匹配的接口是另一个连接ISP的接口，这样一个坏了，还有一个能匹配。
先做192.168.1.0/24网段的测试看看，见以下配置：
r4#sh run
Building configuration…
Current configuration : 1639 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname r4
!
!
ip subnet-zero
!
!
!
!
!
!
interface Loopback0
ip address 4.4.4.4 255.255.255.0
!
interface Ethernet0/0
ip address 192.168.1.4 255.255.255.0
ip nat inside
half-duplex
!
interface Ethernet0/1
ip address 192.168.2.4 255.255.255.0
ip nat inside
half-duplex
!
interface Ethernet0/2
no ip address
shutdown
half-duplex
!
interface Ethernet0/3
no ip address
shutdown
half-duplex
!
interface Serial1/0
ip address 10.0.0.1 255.255.255.0
ip nat outside
shutdown
serial restart-delay 0
!
interface Serial1/1
ip address 20.0.0.1 255.255.255.0
ip nat outside
serial restart-delay 0
!
interface Serial1/2
no ip address
shutdown
serial restart-delay 0
!
interface Serial1/3
no ip address
shutdown
serial restart-delay 0
!
ip nat pool isp1 10.0.0.1 10.0.0.1 prefix-length 24
ip nat pool isp2 20.0.0.1 20.0.0.1 prefix-length 24
ip nat inside source route-map toisp1 pool isp1 overload
ip nat inside source route-map toisp1-2 pool isp2 overload
ip nat inside source route-map toisp2 pool isp2 overload
ip classless
ip route 0.0.0.0 0.0.0.0 10.0.0.3
ip route 0.0.0.0 0.0.0.0 20.0.0.5
ip http server
!
access-list 100 permit ip 192.168.1.0 0.0.0.255 any
access-list 101 permit ip 192.168.2.0 0.0.0.255 any
route-map toisp1 permit 10
match ip address 100
match interface Serial1/0
!
route-map toisp2 permit 10
match ip address 101
match interface Serial1/1
!
route-map toisp1-2 permit 10
match ip address 100
match interface Serial1/1
!
!
line con 0
logging synchronous
line aux 0
line vty 0 4
!
end
=====
看测试结果，此时S1/0仍然是关闭的：
r4#ping
Protocol [ip]:
Target IP address: 10.10.10.10
Repeat count [5]:
Datagram size [100]:
Timeout in seconds [2]:
Extended commands [n]: y
Source address or interface: 192.168.1.4
Type of service [0]:
Set DF bit in IP header? [no]:
Validate reply data? [no]:
Data pattern [0xABCD]:
Loose, Strict, Record, Timestamp, Verbose[none]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.10.10.10, timeout
is 2 seconds:
Packet
sent with a source address of 192.168.1.4
…..
Success rate is 0 percent (0/5)
r4#sh ip nat trans
Pro Inside global Inside local Outside local Outside global
icmp 20.0.0.1:14 192.168.1.4:14 10.10.10.10:14 10.10.10.10:14
注意上面为什么不通!因为这个时候NAT所用的接口池已经是S1/1接口上的了,而我是环境,与S1/1连接的路由器上面没有10.10.10.10这个地址.
From:http://www.mycisco.cn 纳米
看上面的NAT转换表可以证明,发生了转换,而且是用的另一个接口.同理,继续配上192.168.2.0/24网段的备份并测试,配置及测试见下:
r4#sh run
Building configuration…
Current configuration : 1768 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname r4
!
!
ip subnet-zero
!
!
!
!
!
!
interface Loopback0
ip address 4.4.4.4 255.255.255.0
!
interface Ethernet0/0
ip address 192.168.1.4 255.255.255.0
ip nat inside
half-duplex
!
interface Ethernet0/1
ip address 192.168.2.4 255.255.255.0
ip nat inside
half-duplex
!
interface Ethernet0/2
no ip address
shutdown
half-duplex
!
interface Ethernet0/3
no ip address
shutdown
half-duplex
!
interface Serial1/0
ip address 10.0.0.1 255.255.255.0
ip nat outside
serial restart-delay 0
!
interface Serial1/1
ip address 20.0.0.1 255.255.255.0
ip nat outside
serial restart-delay 0
!
interface Serial1/2
no ip address
shutdown
serial restart-delay 0
!
interface Serial1/3
no ip address
shutdown
serial restart-delay 0
!
ip nat pool isp1 10.0.0.1 10.0.0.1 prefix-length 24
ip nat pool isp2 20.0.0.1 20.0.0.1 prefix-length 24
ip nat inside source route-map toisp1 pool isp1 overload
ip nat inside source route-map toisp1-2 pool isp2 overload
ip nat inside source route-map toisp2 pool isp2 overload
ip nat inside source route-map toisp2-1 pool isp1 overload
ip classless
ip route 0.0.0.0 0.0.0.0 10.0.0.3
ip route 0.0.0.0 0.0.0.0 20.0.0.5
ip http server
!
access-list 100 permit ip 192.168.1.0 0.0.0.255 any
access-list 101 permit ip 192.168.2.0 0.0.0.255 any
route-map toisp1 permit 10
match ip address 100
match interface Serial1/0
!
route-map toisp2 permit 10
match ip address 101
match interface Serial1/1
!
route-map toisp1-2 permit 10
match ip address 100
match interface Serial1/1
!
route-map toisp2-1 permit 10
match ip address 101
match interface Serial1/0
!
!
line con 0
logging synchronous
line aux 0
line vty 0 4
!
end
r4#ping
Protocol [ip]:
Target IP address: 20.20.20.20
Repeat count [5]:
Datagram size [100]:
Timeout in seconds [2]:
Extended commands [n]: y
Source address or interface: 192.168.2.4
Type of service [0]:
Set DF bit in IP header? [no]:
Validate reply data? [no]:
Data pattern [0xABCD]:
Loose, Strict, Record, Timestamp, Verbose[none]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 20.20.20.20, timeout is 2 seconds:
Packet sent with a source address of 192.168.2.4
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 12/22/36 ms
r4#
r4#sh ip nat
r4#sh ip nat trans
r4#sh ip nat translations
Pro Inside global Inside local Outside local Outside global
icmp 20.0.0.1:16 192.168.2.4:16 20.20.20.20:16 20.20.20.20:16
=====
上面说明,当S1/1正常的时候,是走的正常的转换,没有使用到备份ISP.
r4#conf t
Enter configuration commands, one per line. End with CNTL/Z.
r4(config)#int s1/1 ‘关闭S1/1准备检验
r4(config-if)#shu
r4(config-if)#end
r4#ping
Protocol [ip]:
01:33:28: %SYS-5-CONFIG_I: Configured from console by console
01:33:29: %LINK-5-CHANGED: Interface Serial1/1, changed state to administratively down
01:33:30: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1/1, changed state to down
Target IP address: 20.20.20.20
Repeat count [5]:
Datagram size [100]:
Timeout in seconds [2]:
Extended commands [n]: y
Source address or interface: 192.168.2.4
Type of service [0]:
Set DF bit in IP header? [no]:
Validate reply data? [no]:
Data pattern [0xABCD]:
Loose, Strict, Record, Timestamp, Verbose[none]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 20.20.20.20, timeout is 2 seconds:
Packet sent with a source address of 192.168.2.4
…..
Success rate is 0 percent (0/5)
r4#sh ip nat trans
Pro Inside global Inside local Outside local Outside global
icmp 10.0.0.1:17 192.168.2.4:17 20.20.20.20:17 20.20.20.20:17
====
看,关闭S1/1,本来是走ISP2所连的接口的,现在被转成了ISP1所连的S1/0接口的地址.当然上面不通是正常的,理由如上面一样,因为是测试环境,ISP1上没有10.10.10.10的地址.
继续深挖,上面的配置看上去好像没有问题,实际上它是正好利用了4个ROUTE-MAP的顺序,因为CISCO路由器在进行有ROUTE-MAP的NAT的时候,是先查ROUTE-MAP的,如果当前ROUTE-MAP里的条件都匹配,那么路由器就会使用调用了该ROUTE-MAP的那条NAT语句,所以这个配置才实现了2个接口都正常时,各个网段走各自的ISP,一旦某个接口DOWN,就走另一个ISP.
对于CISCO路由器到底是不是真的按照先ROUTE-MAP,由ROUTE-MAP再检查ACL这样的顺序,请访问这个地址看试验证明.
另:那个证明的试验是CISCO2500系列下作的,IOS是12.3的非企业版.这次我用的是DYnamips 3620, 12.2非企业版IOS.两次试验都证明了是按照ROUTE-MAP–>ACL的顺序,但是两次也稍微有些不同,2500系列作的ROUTE-MAP排序是按照ROUTE-MAP的名称的字母顺序排的,而这次3620做的,大家看,是按照我配置的先后顺序排的(我实际测试了下,确实是按照配置顺序配的),
这个在实际作的时候应该注意.因为顺序不一样了,很可能就造成本来想192.168.1.0/24走的ISP1,却因为走ISP2(备份)的配置在最前面而导致每次都走ISP2.
(后补充,超级郁闷,不具体说了,大家测试下,在不同IOS上,将上面的配置编辑下,然后复制进去,测试测试看看那几个ROUTE-MAP到底是怎么排序的,我测试ISP1-2,ISP2-1位置可以对调
但想让ISP1-2排最上面,始终不行,复制进去后,一SHOW,就又变成我上面的正常顺序了.晕了,大家测试测试看看吧,把结果留言到这里,感谢!)
t>
对这样的需求,解决办法肯定还有别的,更好的方法,我总觉得,我这样的配置处理效率不是很高(甚至还有我没有想到的错误),请大家到这里留言提出其他方法,一起学习下.
巧用route-map顺序实现不同网段走不同ISP,且互备实验.pdf
[原创]工大CCNP拓扑修改版-Dynamips拓扑配置
今天第一次试用这个模拟器.东西倒是不错,就是俺的电脑…(见网上有人配置比我还底,却能模拟的比我还多,更郁闷)
工大的CCNP 那个拓扑只用了1个E口,这样有些小实验,或者想随手验证某个问题时候,那种拓扑不太灵活.我修改了下,增加一个NM-4E模块,这样扩展到4个E口都连到交换机上,这样可以利用网段逻辑分割.同时对一些小实验也能少开点设备.另外的修改就是改成了3620模拟,7200太费资源了.IOS用的应该不是企业版,可能对一些特殊要求不能满足,但满足日常实验足够了.如果非要替换可以自己换个IOS.没有可以兼得的,IOS功能全,内存占就多,机器就受不料.除非有好机器了.我的机器8台全开,CPU在60%左右,PF占用0.98G左右,同比7200时候是降了很多.基本已经不错了,高档点的配置,占的会更少.
拓扑基本一样,就是每个路由器改为4个E口 f0/0 f0/1 f0/2 f0/3都连到交换机上.另外就是取消掉了ATM. 以下是NET文件:
autostart = false
[localhost]
port = 7200
udp = 10000
[[router R1]]
image = D:\dy6pre2np\dynamips\unzip-c3620-i-mz.122-37.bin
model = 3620
console = 3001
ram = 32
confreg = 0×2142
idlepc = 0x6036ce68
exec_area = 32
mmap = true
slot0=NM-4E
slot1 = PA-4T
f0/0 = SW1 1
f0/1 = SW1 2
f0/2 = SW1 3
f0/3 = SW1 4
s1/1 = R2 s1/0
s1/2 = FR1 1
[[router R2]]
image = D:\dy6pre2np\dynamips\unzip-c3620-i-mz.122-37.bin
model = 3620
console = 3002
ram = 32
confreg = 0×2142
idlepc = 0x6036ce68
exec_area = 32
mmap = true
slot0=NM-4E
slot1 = PA-4T
f0/0 = SW1 5
f0/1 = SW1 6
f0/2 = SW1 7
f0/3 = SW1 8
s1/1 = R3 s1/0
s1/2 = FR1 2
[[router R3]]
image = D:\dy6pre2np\dynamips\unzip-c3620-i-mz.122-37.bin
model = 3620
console = 3003
ram = 32
confreg = 0×2142
idlepc = 0x6036ce68
exec_area = 32
mmap = true
slot0=NM-4E
slot1 = PA-4T
f0/0 = SW1 9
f0/1 = SW1 10
f0/2 = SW1 11
f0/3 = SW1 12
s1/1 = R4 s1/0
s1/2 = FR1 3
[[router R4]]
image = D:\dy6pre2np\dynamips\unzip-c3620-i-mz.122-37.bin
model = 3620
console = 3004
ram = 32
confreg = 0×2142
idlepc = 0x6036ce68
exec_area = 32
mmap = true
slot0=NM-4E
slot1 = PA-4T
f0/0 = SW1 13
f0/1 = SW1 14
f0/2 = SW1 15
f0/3 = SW1 16
s1/1 = R5 s1/0
s1/2 = FR1 4
[[router R5]]
image = D:\dy6pre2np\dynamips\unzip-c3620-i-mz.122-37.bin
model = 3620
console = 3005
ram = 32
confreg = 0×2142
idlepc = 0x6036ce68
exec_area = 32
mmap = true
slot0=NM-4E
slot1 = PA-4T
f0/0 = SW1 17
f0/1 = SW1 18
f0/2 = SW1 19
f0/3 = SW1 20
s1/1 = R6 s1/0
s1/2 = FR1 5
[[router R6]]
image = D:\dy6pre2np\dynamips\unzip-c3620-i-mz.122-37.bin
model = 3620
console = 3006
ram = 32
confreg = 0×2142
idlepc = 0x6036ce68
exec_area = 32
mmap = true
slot0=NM-4E
slot1 = PA-4T
f0/0 = SW1 21
f0/1 = SW1 22
f0/2 = SW1 23
f0/3 = SW1 24
s1/1 = R7 s1/0
s1/2 = FR1 6
[[router R7]]
image = D:\dy6pre2np\dynamips\unzip-c3620-i-mz.122-37.bin
model = 3620
console = 3007
ram = 32
confreg = 0×2142
idlepc = 0x6036ce68
exec_area = 32
mmap = true
slot0=NM-4E
slot1 = PA-4T
f0/0 = SW1 25
s1/1 = R8 s1/0
s1/2 = FR1 7
[[router R8]]
image = D:\dy6pre2np\dynamips\unzip-c3620-i-mz.122-37.bin
model = 3620
console = 3008
ram = 32
confreg = 0×2142
idlepc = 0x6036ce68
exec_area = 32
mmap = true
slot0=NM-4E
slot1 = PA-4T
f0/0 = SW1 26
s1/2 = FR1 8
[[ethsw SW1]]
1 = dot1q 1
2 = dot1q 1
3 = dot1q 1
4 = dot1q 1
5 = dot1q 1
6 = dot1q 1
7 = dot1q 1
8 = dot1q 1
9 = dot1q 1
10 = dot1q 1
11 = dot1q 1
12 = dot1q 1
13 = dot1q 1
14 = dot1q 1
15 = dot1q 1
16 = dot1q 1
17 = dot1q 1
18 = dot1q 1
19 = dot1q 1
20 = dot1q 1
21 = dot1q 1
22 = dot1q 1
23 = dot1q 1
24 = dot1q 1
25 = dot1q 1
26 = dot1q 1
27 = access 1 NIO_gen_eth:\Device\NPF_{186AF844-4284-4049-84BD-70E40AA9AF92}
[[FRSW FR1]]
1:102 = 2
:201
&nbs
p; 1:103 = 3:301
1:104 = 4:401
1:105 = 5:501
1:106 = 6:601
1:107 = 7:701
1:108 = 8:801
2:203 = 3:302
2:204 = 4:402
2:205 = 5:502
2:206 = 6:602
2:207 = 7:702
2:208 = 8:802
3:304 = 4:403
3:305 = 5:503
3:306 = 6:603
3:307 = 7:703
3:308 = 8:803
4:405 = 5:504
4:406 = 6:604
4:407 = 7:704
4:408 = 8:804
5:506 = 6:605
5:507 = 7:705
5:508 = 8:805
6:607 = 7:706
6:608 = 8:806
7:708 = 8:807
[转]网络实践性工作总结[下]
十、TCP/IP症状和行动计划
问题 行动计划
DNS工作不正常 1）配置DNS主机的配置和DNS服务器，可以使用nslookup校验DNS服务器的工作
没有到远程主机的路由 1） 用ipconfig /all检查缺省网关2） 用show ip route查看是否相应路由3） 如果没有该路由，用show ip route查看是否有缺省网关4） 如有网关，检查到目标的下一跳；如无网关，修正问题
ACL 有分离的问题与ACL相关，必须分析ACL、或重写ACL并应用。
网络没有配置以处理应用程序 查看路由器配置
Booting失败 1） 查看DHCP或BootP服务器，并查看是否存在故障机的MAC实体2） 使用debug ip udp校验从主机接收的包3） 校验helper-address正确配置4） 查看ACL是否禁用包
缺少路由 1） 在第1台路由器上用show ip route查看所学到的路由2）校验相邻路由器3）有正确的路由network和neighbor语句4） 对OSPF，校验通配符掩码5） 检查应用到接口上的distribute list6）验证邻居的IP配置7） 如果路由被再发布，验证度量值8） 验证路由被正常的再发布
没有构成相邻关系 1） 用show ip protocol neighbors列表已构成的相邻关系2） 查看没有构成相邻关系的协议配置3）检查路由配置中的network语句4）用show ip protocol/interface查看特定的接口信息，如Hello间隔
第7章 处理串行线路和帧中继连接故障
一、处理串行线路故障
1、HDLC封装
High-level Data Link Control（HDLC）是用于串行链路的一种封装方法，HDLC是Cisco路由器串行接口的缺省封装方法。
处理串行链路故障的第一步就是查看链路两端要使用相同的封装类型。
Show interface serial 1 ；查看接口信息
Clear counters serial number ；复位接口的计数器到0
正常情况下，接口和line都是up的。
线缆故障、载波故障和硬件故障都可导致接口down，通过校验电缆连接、更换硬件（包括电缆）、检查载波信令定位问题。
接口up，line down：CSU/DSU故障、路由器接口问题、CSU/DSU或载波的时间不一致、没有从远端路由器接收到keepalive信令、载波问题。应验证本地接口和远端接口的配置。
接口重启的原因：
? 数秒内排队的包没有被发送；
? 硬件问题（路由器接口、线缆、CSU/DSU）；
? 时钟信令不一致
? 环路接口
? 接口关闭
? 线协议down且接口定期重启
show controllers serial 0 ；显示接口状态、是否连有线缆、时钟速率
show buffers ；查看系统buffer池，接口buffer设置
debug serial interface ；显示HDLC或Frame Relay通信信息
2、CSU/DSU环路测试
有四种类型的环路测试：
? 在本地CSU/DSU上测试本地环路；
? 在远端CSU/DSU上测试本地环路；
? 从本地NIU到远端CSU/DSU测试远端环路；
? 从远端NIU到本地CSU/DSU测试远端环路；
用PPP封装的串行链路上，PPP用协商Magic Number检测环回网络。
3、串行线中总结：
1） 症状和问题：
症状或情形 问题
Interface is administratively down;line protocol is down 1） 接口被从命令行关闭2） 不允许重复的IP地址，两个使用相同IP地址的接口将down
Interface is down;line protocol is down 1） 不合格的线缆2） 没有本地提供商的信令3） 硬件故障（接口或CSU/DSU、线缆）4） 时钟
Interface is up;line protocol is down 1） 未配置的接口：本地或远程2） 本地提供商问题3） Keepalive序号没有增加4） 硬件故障（本地或远端接口、CSU/DSU）5） 线路杂音6） 时钟不一致7） 第2层（如LMI）
Interface is up;line protocol is up(looped) 链路在某处环路
Incrementing carrier transition counter 1） 来自本地提供商的信号不稳定2） 线缆故障3） 硬件故障
Incrementing interface resets 1） 线缆故障，导致CD信号丢失2） 硬件故障3） 线路拥塞
Input drops,errors,CRC,and framing errors 1） 线路速率超过接口能力2） 本地提供商问题3） 线路杂音4） 线缆故障5） 不合格线缆6） 硬件故障
Output drops 接口传输能力超过线路速率
2） 问题和行动
问题 解决行动方案
本地提供商问题 1） 检查CSU/DSU的CD信号和其它信号，看链路是否在发送和接收信息2） 如果没有CD信号或有其它问题，联系本地提供商处理故障
不合格或故障的线缆 1） 使用符合设备要求的线缆2） 使用breakout盒检查3） 交换故障线缆
未配置的接口 1） 使用show running-config校验接口配置2） 确认链路两端使用相同的封装类型
Keepalive问题 1） 验证keepalive被发送2） 配置了keepalive发送，debug keepalive3） 验证序号在增加4） 如果序号不增加，运行环路测试5） CSU/DSU环路，序号仍不增，则硬件故障
硬件故障 1）更换硬件
接口在环路模式 1） 检查接口配置2） 如果在接口配置有环路，移除3） 如果接口配置被清除，清除CSU/DSU环路模式4） 如CSU/DSU不在环路模式，可能是提供商置环
接口administratively down 1） 检查是否有重复的IP地址2） 进行接口配置模式，执行no shutdown
线路速率大于接口能力 1） 使用hold-queue减少进入的队列尺寸2） 增加输出的队列尺寸
接口速率大于线路速率 1） 减少广播流量2） 增加输出的队列3） 如有需要，使用队列算法
二、处理帧中继故障
DLCI用于在帧中继中标识虚拟链路，DLCI仅仅是本地信令，DLCI与第3层IP地址相映射。
处理帧中继的步骤：
1） 检查物理层，线缆或接口问题；
2） 检查接口封装；
3） 检查LMI类型；
4） 校验DLCI到IP的映射；
5） 校验Frame Delay的PVC；
6） 校验Frame Delay的LMI；
7） 校验Frame Delay映射；
8） 校验环路测试；
1、帧中继的show命令
show interface
show frame-relay lmi ；显示LMI相关信息（LMI类型、更新、状态）
show frame-relay pvc ；输出PVC信息、每条DLCI的LMI状态、…）
show frame-relay map ；提供DLCI号信息和所有FR接口的封装
2、帧中继的debug命令
debug frame-relay lmi ；显示LMI交换信息
debug frame-relay events ；显示协议和应用程序使用DLCI的细节
3、帧中继总纳
1） 症状和问题
症状或情形 相关问题
Frame Realy link is down 1） 线缆故障2） 硬件故障3） 本地服务商问题4） LMI类型不一致5） Keepalive没有被发送6） 封装类型不一致7） DLCI不一致
从Frame Delay网络不能ping远端主机 1） DLCI指定了错误的接口2） 封装类型不一致3） ACL问题4） 接口配置错误
2） 问题和行动
问题 解决行动方案
线缆故障 1） 检查线缆并测试接头2） 更换线缆
硬件故障 1） 执行环路测试，以分离硬件2） 将线缆连接到路由器的另一同样配置的接口，如OK，则需更换硬件
本地服务提供商问题 1） 如环路测试使LMI状态up，但不能连接远端着站点，联系本地载波2） 包含载波问题，就好象FR配置错误，如DLCI不一致或封装不一致。
LMI类型不一致 1） 校验路由器的LMI类型与PVC上的每个设备都一致2） 如
使用公共提供商网
[转]网络实践性工作总结[上]
1章 故障处理方法
一、网络的复杂性
一般网络包括路由、拨号、交换、视频、WAN（ISDN、帧中继、ATM、…）、LAN、VLAN、…
二、故障处理模型
1、 界定问题（Define the Problem）
详细而精确地描述故障的症状和潜在的原因
2、 收集详细信息（Gather Facts）R>信息来源：关键用户、网络管理系统、路由器/交换机
1） 识别症状：
2） 重现故障：校验故障依然存在
3） 调查故障频率：
4） 确定故障的范围：有三种方法建立故障范围
? 由外到内故障处理（Outside-In Troubleshooting）：通常适用于有多个主机不能连接到一台服务器或服务器集
? 由内到外故障处理（Inside-Out Troubleshooting）：
? 半分故障处理（Divide-by-Half Troubleshooting）
3、 考虑可能情形（Consider Possibilities）考虑引起故障的可能原因
4、 建立一份行动计划（Create the Action Plan）
5、 部署行动计划（Implement the Action Plan）
用于纠正网络故障原因。从最象故障源处，想出处理方法每完成一个步骤，检查故障是否解决
6、 观察行动计划执行结果（Observe Results）
7、 如有行动计划不能解决问题，重复上述过程（Iterate as Needed）
三、记录所做修改
在通过行动计划解决问题后，建议把记录作为故障处理的一部分，记录所有的配置修改。
第2章 网络文档
一、网络基线
解决网络问题的最简单途径是把当前配置和以前的配置相比较。
基线文档由不同的网络和系统文档组成，它包括：
? 网络配置表
? 网络拓扑图
? ES网络配置表
? ES网络拓扑图
创建网络的注意事项：
1） 确定文档覆盖的范围；
2） 保持一致：收集网络中所有设备的相同信息；
3） 明确目标：了解文档的用途；
4） 文档易于使用和访问；
5） 及时维护更新文档。
二、网络配置表
网络配置表的通常目标是提供网络中使用的硬件和软件组成的列表，其组成有：
分级 项目
杂项信息 设备名、设备型号、CPU类型、FLASH、DRAM、接口描述、用户名口令
第1层 介质类型、速率、双工模式、接口号、连接插座或端口
第2层 MAC地址、STP状态、STP根桥、速端口信息、VLAN、Etherchannel配置、封装、中继状态、接口类型、端口安全、VTP状态、VTP模式
第3层 IP地址、IPX地址、HSRP地址、子网掩码、路由协议、ACL、隧道信息、环路接口
在多数情形下，存储这些信息的最佳方式是电子表格或数据库，电子表格用于较小的网络，数据库用于较大的网络。
三、网络拓扑图
网络拓扑图是图示网络的各组成部分之间如何在逻辑上和物理上相互连接。
1、网络拓扑图的组成
分级 项目
杂项信息 设备名、设备型号、设置间连接、接口描述
第1层 介质类型、接口号
第2层 MAC地址、VLAN、封装、中继状态、接口类型、DLCI
第3层 IP地址、子网掩码、路由协议
对于大型的网络，可以制作多个网络拓扑图，每个网络拓扑图反映一个分离的部分。
2、建立网络拓扑图
四、发现网络配置信息
1、收集路由器和第3层交换机网络配置信息
show version ；显示设备型号、Flash、DRAM、IOS版本
show ip interface brief ；显示接口简要信息（类型、状态、协议状态、IP地址）
show interface e0/0 ；显示某接口详细信息（MAC、IP、MASK、…）
show ip protocols ；显示IP路由协议信息
show ip interface e0/0 ；显示接口的IP协议信息（状态、IP地址、ACL、…）
2、收集交换机配置信息
交换机网络配置表包含的信息：设备名、型号、位置、Flash、DRAM、CATOS版本、管理地址、VTP域、VTP模式、端口号、端口速率、端口双工、VLAN、STP状态、速端口状态、中继状态、…
show version ；显示IOS或CATOS版本、DRAM、Flash
show vtp domain ；（CatOS）显示VTP域和VTP模式
show vtp status ；（IOS）
show interface ；（CatOS）显示管理接口信息
show port ；（CatOS）显示每个端口的简要信息（号、VLAN、双工、…）
show interface ；（IOS）
show trunk ；（CatOS）显示中继信息（模式、封装、允许端口、剪裁、…）
show interface trunk ；（IOS）
show spantree 45 ；（CatOS）显示端口的STP模式、类型、状态、速端口、…）
show spanning-tree 45 ；（IOS）
3、发现相邻CISCO设备的信息
CDP（Cisco Discovery Protocol）是CISCO的专用协议，用于识别直接相邻的CISCO设备信息，CDP工作在第2层。
Show cdp neighbor ；显示相邻CISCO设备的简要信息（ID、相邻接口、平台、…）
Show cdp neighbor detail；显示相邻CISCO设备的详细信息（包含第3层信息）
五、创建网络文档的过程
1、 LOGIN ；登录到设备进入特权模式。
2、 接口发现 ；发现关于设备的所需信息
3、 Document ；在网络配置表中记录发现的信息。
4、 Diagram ；从网络配置表传输所需信息到网络拓扑图
5、 设备发现 ；判断是否有相邻设备没有记录文档。
第3章 ES文档和故障处理
一、ES网络配置表
ES网络配置表是ES的硬件和软件组成的列表。ES网络配置常包括以下项目：
分级 项目
杂项信息 系统名、系统厂商/型号、CPU速率、RAM、存储器、系统功能
第1、2层 介质类型、接口速率、VLAN、MAC、网络接头
第3层 IP地址、缺省网关、子网掩码、WINS、DNS、
第7层 操作系统（版本）、基于网络的应用程序、高带宽应用程序、低延时应用程序、特定考虑
二、ES网络拓扑图
ES网络拓扑图的典型项目有：系统名、网络连接、物理位置、系统目标、VLAN、IP地址、子网掩码、操作系统、网络应用程序
大多数ES网络拓扑图都建立在网络拓扑图中，其中还可加入ES网络配置表数据的子集。
三、收集ES网络配置信息
通用命令：
1） ping host/ip-address ；发送和接收ICMP响应，校验网络的连通性
2） arp -a ；查看修改ES的MAC-IP映射表（同一子网）
3） telnet host/ip-address ；登录远程ES或特定TCP端口
Windows平台命令
1） ipconfig /all ；查看修改ES的IP信息（适用所有Windows平台）
2） winipcfg ；查看修改ES的IP信息（仅适用于Win9x平台）
3） tracert host/ip-address ；校验到主机的连接并显示路径上的设备IP
4） route print ；显示本设备IP路由表的内容
5） netstat ；显示当前网络连接
Unix、Linux和Mac OS系统命令
1） ifconfig -a ；查看UNIX和MAC主机的IP信息
2） traceroute host/ip ；
3） route –n ；
4） cat /etc/resolv.conf ；查看DNS服务器信息
四、通用的故障处理过程
1、通用的故障处理过程：
> l 收集症状：
[原创]BSCI第三章实验之任务三,四,五(人邮自学指南BSCI)
拓扑图以及实际用路由器名与书上路由器名对应关系,请查看[原创]BSCI第一章实验2之任务2(人邮自学指南BSCI)
下面的调试信息是在P1R1 P1R2上启用路由汇总后,并关闭P1R1的S1接口后,在R5上看到的,注意看由于配置了汇总路由,R5对查询应答很快,它不会再向外发出继续查询的信息,直接用某某具体的子网不在我的路由表里 not in IP routing table 来应答.这样就避免了过渡的查询数据占用带宽.
r5-2501#
*Mar 1 02:59:50.011: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming QUERY packet
*Mar 1 02:59:50.015: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 4294967295 – 0 4294967295 SM 4294967295 – 0 4294967295
*Mar 1 02:59:50.023: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.1.0/24 M 4294967295 – 1657856 4294967295 SM 4294967295 – 1657856 4294967295
*Mar 1 02:59:50.043: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.0.0/24 – not in IP routing table
*Mar 1 02:59:50.047: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 metric 4294967295 – 0 4294967295
*Mar 1 02:59:50.051: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.1.0/24 – not in IP routing table
另一种减少查询的方法就是在不需要保存保存大量路由信息的远程路由器上启用末节eigrp stub特性,启用末节特性后,末节路由器将不会接受查询,如下面的红色显示,整个信息显示也没有 incoming query.
2509rj#3
[Resuming connection 3 to r3 ... ]
*Mar 1 03:24:03.131: IP-EIGRP(Default-IP-Routing-Table:1): Neighbor 10.1.2.2 not on common subnet for Ethernet0
r3-2514(config-router)#
*Mar 1 03:24:09.303: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming UPDATE packet
*Mar 1 03:24:09.307: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 4294967295 – 0 4294967295 SM 4294967295 – 0 4294967295
r3-2514(config-router)#
*Mar 1 03:24:12.207: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming UPDATE packet
*Mar 1 03:24:12.211: IP-EIGRP(Default-IP-Routing-Table:1): Int 2.0.0.0/8 M 2323456 – 1657856 665600 SM 2297856 – 1657856 640000
*Mar 1 03:24:12.215: IP-EIGRP(Default-IP-Routing-Table:1): Int 4.0.0.0/8 M 2349056 – 1657856 691200 SM 2323456 – 1657856 665600
*Mar 1 03:24:12.239: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming UPDATE packet
*Mar 1 03:24:12.243: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 4294967295 – 0 4294967295 SM 4294967295 – 0 4294967295
*Mar 1 03:24:12.251: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.2.0/24 M 4294967295 – 1657856 4294967295 SM 4294967295 – 1657856 4294967295
*Mar 1 03:24:12.263: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 metric 4294967295 – 0 4294967295
*Mar 1 03:24:12.271: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.0.0/24 – denied by stub
*Mar 1 03:24:12.275: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.
1.0.0/24 metric 4294967295 – 0 4294967295
*Mar 1 03:24:12.299: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming REPLY packet
*Mar 1 03:24:12.303: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 4294967295 – 0 4294967295 SM 4294967295 – 0 4294967295
*Mar 1 03:24:12.327: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming REPLY packet
*Mar 1 03:24:12.331: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 4294967295 – 0 4294967295 SM 4294967295 – 0 4294967295
r3-2514(config-router)#un all
启用末节特性后,在R1上显示邻居,注意蓝色部分:
r1-2514>show ip eigrp neighbors detai
IP-EIGRP neighbors for process 1
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
1 10.1.1.3 Et0 13 00:17:40 1010 5000 0 123
Version 12.3/1.2, Retrans: 1, Retries: 0
Stub Peer Advertising ( CONNECTED SUMMARY ) Routes
Suppressing queries
3 172.31.1.2 Se0 134 00:40:07 57 342 0 165
Version 12.3/1.2, Retrans: 1, Retries: 0
2 172.31.1.5 Se0 161 00:41:33 36 216 0 42
Version 12.3/1.2, Retrans: 9, Retries: 0
另外:
如果在R3上启用eigrp stub receive-only的话,那么R3就不会把自己的路由发送给其他邻居了.看下面的输出:
r1-2514#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
C 1.0.0.0/8 is directly connected, Loopback0
D 2.0.0.0/8 [90/2297856] via 172.31.1.2, 00:18:57, Serial0
D 3.0.0.0/8 [90/409600] via 10.1.1.3, 00:22:29, Ethernet0
D 4.0.0.0/8 [90/2323456] via 172.31.1.2, 00:18:57, Serial0
D 5.0.0.0/8 [90/2297856] via 172.31.1.5, 00:27:59, Serial0
172.31.0.0/24 is subnetted, 1 subnets
C 172.31.1.0 is directly connected, Serial0
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
D 10.1.3.0/24 [90/2195456] via 10.1.1.3, 00:22:30, Ethernet0
C 10.1.1.0/24 is directly connected, Ethernet0
D 10.1.0.0/16 is a summary, 00:44:56, Null0
D 10.254.0.0/24 [90/2195456] via 172.31.1.5, 00:28:01, Serial0
下面是eigrp stub receive-only启用之后
r1-2514#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
&nbs
p; i – IS-IS,
su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
C 1.0.0.0/8 is directly connected, Loopback0
D 2.0.0.0/8 [90/2297856] via 172.31.1.2, 00:22:36, Serial0
D 4.0.0.0/8 [90/2323456] via 172.31.1.2, 00:22:36, Serial0
D 5.0.0.0/8 [90/2297856] via 172.31.1.5, 00:31:38, Serial0
172.31.0.0/24 is subnetted, 1 subnets
C 172.31.1.0 is directly connected, Serial0
10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks
C 10.1.1.0/24 is directly connected, Ethernet0
D 10.1.0.0/16 is a summary, 00:48:33, Null0
D 10.254.0.0/24 [90/2195456] via 172.31.1.5, 00:31:39, Serial0
启用前红色部分的路由条目在启用后消失了.!
任务五:
利用通告0.0.0.0 0.0.0.0汇总路由的方式向其他路由器通告默认路由的方式,不但通告了默认路由,还过滤了自身其他路由条目被发送给对方路由器.如下:
通告默认路由前 R3的路由表,注意加粗的红色部分,此时R3有通过R1接口的路由:
r3-2514(config-router)#do show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
D 1.0.0.0/8 [90/409600] via 10.1.1.1, 00:22:57, Ethernet0
D 2.0.0.0/8 [90/2323456] via 10.1.1.1, 00:22:57, Ethernet0
[90/2323456] via 10.1.3.4, 00:22:57, Serial1
C 3.0.0.0/8 is directly connected, Loopback0
D 4.0.0.0/8 [90/2297856] via 10.1.3.4, 00:22:57, Serial1
D 5.0.0.0/8 [90/2323456] via 10.1.1.1, 00:22:57, Ethernet0
172.31.0.0/24 is subnetted, 1 subnets
D 172.31.1.0 [90/2195456] via 10.1.1.1, 00:22:57, Ethernet0
10.0.0.0/24 is subnetted, 4 subnets
C 10.1.3.0 is directly connected, Serial1
D 10.1.2.0 [90/2195456] via 10.1.3.4, 00:19:20, Serial1
C 10.1.1.0 is directly connected, Ethernet0
D 10.254.0.0 [90/2221056] via 10.1.1.1, 00:22:58, Ethernet0
再看通告后的,除多了默认路由外,:原来到达5.0.0.0/8网络的路由条目,现在经过10.1.3.4接口走了,而不是R1的10.1.1.1了
r3-2514#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is 10.1.1.1 to network 0.0.0.0
D 1.0.0.0/8 [90/2835456] via 10.1.3.4, 00:00:09, Serial1
D 2.0.0.0/8 [90/2323456] via 10.1.3.4, 00:00:09, Serial1
C 3.0.0.0/8 is directly connected, Loopback0
D 4.0.0.0/8 [90/2297856] via 10.1.3.4, 00:07:30, Serial1
D 5.0.0.0/8 [90/2835456] via 10.1.3.4, 00:00:09, Serial1
172.31.0.0/24 is subnetted, 1 subnets
D 172.31.1.0 [90/2707456] via 10.1.3.4, 00:00:09, Serial1
10.0.0.0/24 is subnetted, 4 subnets
C 10.1.3.0 is directly connected, Serial1
D 10.1.2.0 [90/2195456] via 10.1.3.4, 00:07:32, Serial1
C 10.1.1.0 is directly connected, Ethernet0
D 10.254.0.0 [90/2733056] via 10.1.3.4, 00:00:10, Serial1
D* 0.0.0.0/0 [90/409600] via 10.1.1.1, 00:00:04, Ethernet0
[原创]BSCI第三章实验之任务一,二(人邮自学指南BSCI)
任务是删除上一次配置 没什么可说了,拓扑图以及实际用路由器名与书上路由器名对应关系,请查看[原创]BSCI第一章实验2之任务2(人邮自学指南BSCI)
未关闭S1前 R1
r1-2514#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
C 1.0.0.0/8 is directly connected, Loopback0
D 2.0.0.0/8 [90/2297856] via 172.31.1.2, 00:00:59, Serial0
[90/2297856] via 10.1.0.2, 00:00:59, Serial1
D 3.0.0.0/8 [90/409600] via 10.1.1.3, 00:45:56, Ethernet0
D 4.0.0.0/8 [90/2323456] via 10.1.1.3, 00:00:59, Ethernet0
[90/2323456] via 172.31.1.2, 00:00:59, Serial0
[90/2323456] via 10.1.0.2, 00:00:59, Serial1
172.31.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.31.1.0/24 is directly connected, Serial0
D 172.31.0.0/16 is a summary, 00:01:01, Null0
10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
D 10.1.3.0/24 [90/2195456] via 10.1.1.3, 00:01:01, Ethernet0
D 10.1.2.0/24 [90/2195456] via 10.1.0.2, 00:01:01, Serial1
C 10.1.1.0/24 is directly connected, Ethernet0
D 10.0.0.0/8 is a summary, 00:41:22, Null0
C 10.1.0.0/24 is directly connected, Serial1
关闭S1后的r1
r1-2514#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
C 1.0.0.0/8 is directly connected, Loopback0
D 2.0.0.0/8 [90/2297856] via 172.31.1.2, 00:00:10, Serial0
D 3.0.0.0/8 [90/409600] via 10.1.1.3, 00:00:10, Ethernet0
D 4.0.0.0/8 [90/2323456] via 172.31.1.2, 00:00:10, Serial0
[90/2323456] via 10.1.1.3, 00:00:10, Ethernet0
172.31.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.31.1.0/24 is directly connected, Serial0
D 172.31.0.0/16 is a summary, 00:00:10, Null0
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
D 10.1.3.0/24 [90/2195456] via 10.1.1.3, 00:00:11, Ethernet0
D 10.1.2.0/24 [90/2221056] via 10.1.1.3, 00:00:11, Ethernet0
C 10.1.1.0/24 is directly connected, Ethernet0
D 10.0.0.0/8 is a summary, 00:00:11, Null0
未关闭R1-S1前R3
r3-2514#
*Mar 1 01:25:48.275: IP-EIGRP(Default-IP-Routing-Table:1): Neighbor 10.1.2.4 not on common subnet for Ethernet0
r3-2514#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
D 1.0.0.0/8 [90/409600] via 10.1.1.1, 01:11:19, Ethernet0
D 2.0.0.0/8 [90/2323456] via 10.1.1.1, 00:42:18, Ethernet0
[90/2323456] via 10.1.3.4, 00:42:18, Serial1
C 3.0.0.0/8 is directly connected, Loopback0
D 4.0.0.0/8 [90/2297856] via 10.1.3.4, 01:09:32, Serial1
D 172.31.0.0/16 [90/2195456] via 10.1.1.1, 00:42:19, Ethernet0
10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
C 10.1.3.0/24 is directly connected, Serial1
D 10.1.2.0/24 [90/2195456] via 10.1.3.4, 00:02:04, Serial1
C 10.1.1.0/24 is directly connected, Ethernet0
D 10.0.0.0/8 is a summary, 01:10:59, Null0
D 10.1.0.0/24 [90/2195456] via 10.1.1.1, 00:02:06, Ethernet0
关闭R1-S1后的R3
r3-2514#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
D 1.0.0.0/8 [90/409600] via 10.1.1.1, 01:28:15, Ethernet0
D 2.0.0.0/8 [90/2323456] via 10.1.1.1, 00:59:14, Ethernet0
[90/2323456] via 10.1.3.4, 00:59:14, Serial1
C 3.0.0.0/8 is directly connected, Loopback0
D 4.0.0.0/8 [90/2297856] via 10.1.3.4, 01:26:28, Serial1
D 172.31.0.0/16 [90/2195456] via 10.1.1.1, 00:59:14, Ethernet0
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
C 10.1.3.0/24 is directly connected, Serial1
D 10.1.2.0/24 [90/2195456] via 10.1.3.4, 00:19:00, Serial1
C 10.1.1.0
/24 is directly connected,
Ethernet0
D 10.0.0.0/8 is a summary, 01:27:54, Null0
注意上面有个汇总路由,这是自动出来的,EIGRP在汇总路由时总会产生一条指向NULL0接口的路由,这样避免在某些情况下,产生路由环路.比如有一个目标网络是汇总网络里的一个未知子网,此时如果存在默认路由指向发来数据包的路由器,那么这个时候如果没有指向NULL0的这条路由,路由器将把数据包通过默认路由发回原路由器了,产生了环路.而有了指向NULL0接口的这个路由,路由器会匹配它并丢到NULL0上,也就丢弃了数据包.
关闭前R1 到10.1.2.0是通过R2—目标
关闭后R1 到10.1.2.0是通过R3–R4—目标
关闭前R3 到10.1.2.0是通过R4—目标
关闭后R3 到10.1.2.0是通过R4—目标
最终R3无到达10.1.0.0/24的网络
关闭后R3上调试信息:
2509rj#3
[Resuming connection 3 to r3 ... ]
*Mar 1 01:12:23.507: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming QUERY packet
*Mar 1 01:12:23.511: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 4294967295 – 0 4294967295 SM 4294967295 – 0 4294967295
*Mar 1 01:12:23.515: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.2.0/24 M 4294967295 – 1657856 4294967295 SM 4294967295 – 1657856 4294967295
R1路由器向R3发起了2个网络的查询,用4294967295表示我不可达这个网络,你有无去往的路径.
*Mar 1 01:12:23.531: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 metric 4294967295 – 0 4294967295
*Mar 1 01:12:23.539: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.0.0/24 – do advertise out Serial1 ‘自己无FS于是自己继续向邻居查询
*Mar 1 01:12:23.543: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 metric 4294967295 – 0 4294967295
*Mar 1 01:12:23.555: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming UPDATE packet
*Mar 1 01:12:23.559: IP-EIGRP(Default-IP-Routing-Table:1): Int 2.0.0.0/8 M 2323456 – 1657856
665600 SM 2297856 – 1657856 640000
*Mar 1 01:12:23.563: IP-EIGRP(Default-IP-Routing-Table:1): Int 4.0.0.0/8 M 4294967295 – 1657856 4294967295 SM 4294967295 – 1657856 4294967295
*Mar 1 01:12:23.587: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.2.0/24 – do advertise out Ethernet0
*Mar 1 01:12:23.595: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.2.0/24 metric 2195456 – 1657856 537600
*Mar 1 01:12:23.603: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming REPLY packet
*Mar 1 01:12:23.607: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 2707456 – 1657856 1049600 SM 2195456 – 1657856 537600
*Mar 1 01:12:23.627: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming REPLY packet
*Mar 1 01:12:23.631: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 4294967295 – 0 4294967295 SM 4294967295 – 0 4294967295
*Mar 1 01:12:23.639: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.0.0/24 routing table not updated thru 10.1.1.1
*Mar 1 01:12:23.663: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 metric 2707456 – 1657856 1049600
*Mar 1 01:12:23.671: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.0.0/24 – do advertise out Ethernet0
*Mar 1 01:12:23.675: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 metric 2707456 – 1657856 1049600
*Mar 1 01:12:23.695: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming UPDATE packet
*Mar 1 01:12:23.699: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.2.0/24 M 4294967295 – 1657856 4294967295 SM 4294967295 – 1657856 4294967295
*Mar 1 01:12:23.719: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.0.0/24 – do advertise out Ethernet0
*Mar 1 01:12:23.723: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 metric 2707456 – 1657856 1049600
*Mar 1 01:12:23.735: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming UPDATE packet
*Mar 1 01:12:23.739: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 4294967295 – 1657856 4294967295 SM 4294967295 – 1657856 4294967295
*Mar 1 01:12:25.575: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming QUERY packet
*Mar 1 01:12:25.579: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 4294967295 – 0 4294967295 SM 4294967295 – 0 4294967295
*Mar 1 01:12:25.603: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.0.0/24 – do advertise out Ethernet0
*Mar 1 01:12:25.607: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 metric 4294967295 – 0 4294967295
*Mar 1 01:12:25.647: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming QUERY packet
*Mar 1 01:12:25.651: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 4294967295 – 0 4294967295 SM 4294967295 – 0 4294967295
*Mar 1 01:12:25.679: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.0.0/24 – do advertise out Ethernet0
*Mar 1 01:12:25.683: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 metric 4294967295 – 0 4294967295
*Mar 1 01:12:25.735: IP-EIGRP(Default-IP-Routing-Table:1): Processing incoming REPLY packet
*Mar 1 01:12:25.739: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 M 4294967295 – 0 4294967295 SM 4294967295 – 0 4294967295
*Mar 1 01:12:25.747: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.0.0/24 routing table not updated thru 10.1.3.4
*Mar 1 01:12:25.775: IP-EIGRP(Default-IP-Routing-Table:1): 10.1.0.0/24 – not in IP routing table
最终路由器无法从其他路由器获得替代路径,将改条目从陆游表中删除
*Mar 1 01:12:25.779: IP-EIGRP(Default-IP-Routing-Table:1): Int 10.1.0.0/24 metric 4294967295 – 0 4294967295r3-2514#
r3-2514#un all
至于中间有那么多次E0口上的查询等,可能是因为实验实际环境是路由器的所有E口都接在一台交换机上,而更新查询使用的是多播,每台路由器的查询它都能接到,才会导致这么条目显示.
这个问题,在路由器上不停提示大量提示:*Mar 1 02:14:23.571: IP-EIGRP(Default-IP-Routing-Table:1): Neighbor 10.1.2.4 not on common subnet for Ethernet0的原因是一样的.路由器从交换机上接到了一个HELLO包,而发送HELLO的路由器不是它的真正邻居,所以就报邻居E0不是合法子网.可以看下HELLO调试信息:
r3-2514#debug eigrp packets
*Mar 1 00:31:32.343: IP-EIGRP(Default-IP-Routing-Table:1): Neighbor 10.1.2.4 not on common subnet for Ethernet0
r3-2514#debug eigrp packets
EIGRP Packets debugging is on
(UPDATE, REQUEST, QUERY, REPLY, HELLO, IPXSAP, PROBE, ACK, STUB, SIAQUERY, SIAREPLY)
r3-2514#
*Mar 1 00:31:34.287: EIGRP: Received HELLO on Ethernet0 nbr 10.1.1.1
*Mar 1 00:31:34.291: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
*Mar 1 00:31:34.607: EIGRP: Sending HELLO on Serial1
*Mar 1 00:31:34.611: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
r3-2514#
*Mar 1 00:31:35.731: EIGRP: Received HELLO on Serial1 nbr 10.1.3.4
*Mar 1 00:31:35.731: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#
*Mar 1 00:31:36.891: EIGRP: Received HELLO on Ethernet0 nbr 10.1.2.4
*Mar 1 00:31:36.891: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:31:37.095: EIGRP: Sending HELLO on Loopback0
*Mar 1 00:31:37.099: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:31:37.103: EIGRP: Received HELLO on Loopback0 nbr 3.3.3.3
*Mar 1 00:31:37.107: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:31:37.111: EIGRP: Packet from ourselves ignored
*Mar 1 00:31:37.711: EIGRP: Sending HELLO on Ethernet0
*Mar 1
00:31:37.715: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
r3-2514#
*Mar 1 00:31:39.019: EIGRP: Sending HELLO on Serial1
*Mar 1 00:31:39.023: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:31:39.095: EIGRP: Received HELLO on Ethernet0 nbr 10.1.1.1
*Mar 1 00:31:39.099: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#
*Mar 1 00:31:40.279: EIGRP: Received HELLO on Serial1 nbr 10.1.3.4
*Mar 1 00:31:40.279: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#
*Mar 1 00:31:41.619: EIGRP: Received HELLO on Ethernet0 nbr 10.1.2.4
*Mar 1 00:31:41.619: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:31:41.819: EIGRP: Sending HELLO on Loopback0
*Mar 1 00:31:41.823: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:31:41.839: EIGRP: Received HELLO on Loopback0 nbr 3.3.3.3
*Mar 1 00:31:41.843: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:31:41.847: EIGRP: Packet from ourselves ignored
*Mar 1 00:31:42.579: EIGRP: Sending HELLO on Ethernet0
*Mar 1 00:31:42.583: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
r3-2514#
*Mar 1 00:31:43.411: EIGRP: Received HELLO on Ethernet0 nbr 10.1.1.1
*Mar 1 00:31:43.415: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
*Mar 1 00:31:43.487: EIGRP: Sending HELLO on Serial1
*Mar 1 00:31:43.491: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
r3-2514#
*Mar 1 00:31:45.003: EIGRP: Received HELLO on Serial1 nbr 10.1.3.4
*Mar 1 00:31:45.007: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#
*Mar 1 00:31:46.587: EIGRP: Received HELLO on Ethernet0 nbr 10.1.2.4
*Mar 1 00:31:46.587: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:31:46.591: IP-EIGRP(Default-IP-Routing-Table:1): Neighbor 10.1.2.4 not on common subnet for Ethernet0
*Mar 1 00:31:46.819: EIGRP: Sending HELLO on Loopback0
*Mar 1 00:31:46.823: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:31:46.827: EIGRP: Received HELLO on Loopback0 nbr 3.3.3.3
*Mar 1 00:31:46.831: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:31:46.835: EIGRP: Packet from ourselves ignored
*Mar 1 00:31:47.107: EIGRP: Sending HELLO on Ethernet0
*Mar 1 00:31:47.111: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
r3-2514# iidbQ un/rely 0/0
*Mar 1 00:31:47.883: EIGRP: Received HELLO on Ethernet0 nbr 10.1.1.1
*Mar 1 00:31:47.887: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#
*Mar 1 00:31:48.315: EIGRP: Sending HELLO on Serial1
*Mar 1 00:31:48.319: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
r3-2514#
*Mar 1 00:31:49.535: EIGRP: Received HELLO on Serial1 nbr 10.1.3.4
*Mar 1 00:31:49.535: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#
*Mar 1 00:31:50.911: EIGRP: Received HELLO on Ethernet0 nbr 10.1.2.4
*Mar 1 00:31:50.911: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:31:51.091: EIGRP: Sending HELLO on Loopback0
*Mar 1 00:31:51.095: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:31:51.099: EIGRP: Received HELLO on Loopback0 nbr 3.3.3.3
*Mar 1 00:31:51.103: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:31:51.107: EIGRP: Packet from ourselves ignored
r3-2514#
*Mar 1 00:31:51.915: EIGRP: Sending HELLO on Ethernet0
*Mar 1 00:31:51.919: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:31:52.791: EIGRP: Received HELLO on Ethernet0 nbr 10.1.1.1
*Mar 1 00:31:52.795: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#
*Mar 1 00:31:53.195: EIGRP: Sending HELLO on Serial1
*Mar 1 00:31:53.199: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:31:53.983: EIGRP: Received HELLO on Serial1 nbr 10.1.3.4
*Mar 1 00:31:53.983: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#
*Mar 1 00:31:55.435: EIGRP: Received HELLO on Ethernet0 nbr 10.1.2.4
*Mar 1 00:31:55.435: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:31:55.739: EIGRP: Sending HELLO on Loopback0
*Mar 1 00:31:55.743: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:31:55.747: EIGRP: Received HELLO on Loopback0 nbr 3.3.3.3
*Mar 1 00:31:55.751: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:31:55.755: EIGRP: Packet from ourselves ignored
r3-2514#
*Mar 1 00:31:56.811: EIGRP: Sending HELLO on Ethernet0
*Mar 1 00:31:56.815: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:31:57.391: EIGRP: Received HELLO on Ethernet0 nbr 10.1.1.1
*Mar 1 00:31:57.395: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
*Mar 1 00:31:57.623: EIGRP: Sending HELLO on Serial1
*Mar 1 00:31:57.627: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
r3-2514#
*Mar 1 00:31:58.875: EIGRP: Received HELLO on Serial1 nbr 10.1.3.4
*Mar 1 00:31:58.875: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#
*Mar 1 00:32:00.031: EIGRP: Received HELLO on Ethernet0 nbr 10.1.2.4
*Mar 1 00:32:00.031: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:32:00.035: IP-EIGRP(Default-IP-Routing-Table:1): Neighbor 10.1.2.4 not on common subnet for Ethernet0
*Mar 1 00:32:00.079: EIGRP: Sending HELLO on Loopback0
*Mar 1 00:32:00.083: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:32:00.087: EIGRP: Received HELLO on Loopback0 nbr 3.3.3.3
*Mar 1 00:32:00.091: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:32:00.095: EIGRP: Packet from ourselves ignored
r3-2514#
*Mar 1 00:32:01.207: EIGRP: Sending HELLO on Ethernet0
*Mar 1 00:32:01.211: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:32:01.979: EIGRP: Received HELLO on Ethernet0 nbr 10.1.1.1
*Mar 1 00:32:01.983: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#
*Mar 1 00:32:02.519: EIGRP: Sending HELLO on Serial1
*Mar 1 00:32:02.523: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
r3-2514#
*Mar 1 00:32:03.623: EIGRP: Received HELLO on Serial1 nbr 10.1.3.4
*Mar 1 00:32:03.623: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#
*Mar 1 00:32:04.659: EIGRP: Sending HELLO on Loopback0
*Mar 1 00:32:04.663: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:32:04.667: EIGRP: Received HELLO on Loopback0 nbr 3.3.3.3
*Mar 1 00:32:04.671: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:32:04.675: EIGRP: Packet from ourselves ignored
*Mar 1 00:32:04.879: EIGRP: Received HELLO on Ethernet0 nbr 10.1.2.4
*Mar 1 00:32:04.879: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
r3-2514#
*Mar 1 00:32:06.035: EIGRP: Sending HELLO on Ethernet0
*Mar 1 00:32:06.039: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un
/rely 0/0
*Mar 1 00:32:06.923: EIGRP: Received HELLO on Ethernet0 nbr 10.1.1.1
*Mar 1 00:32:06.927: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
*Mar 1 00:32:06.931: EIGRP: Sending HELLO on Serial1
*Mar 1 00:32:06.935: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
r3-2514#
*Mar 1 00:32:07.943: EIGRP: Received HELLO on Serial1 nbr 10.1.3.4
*Mar 1 00:32:07.943: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
r3-2514#uanl
*Mar 1 00:32:09.147: EIGRP: Sending HELLO on Loopback0
*Mar 1 00:32:09.151: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:32:09.155: EIGRP: Received HELLO on Loopback0 nbr 3.3.3.3
*Mar 1 00:32:09.159: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
*Mar 1 00:32:09.163: EIGRP: Packet from ourselves ignored
*Mar 1 00:32:09.399: EIGRP: Received HELLO on Ethernet0 nbr 10.1.2.4
*Mar 1 00:32:09.403: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0
r3-2514#un
*Mar 1 00:32:10.379: EIGRP: Sending HELLO on Ethernet0
*Mar 1 00:32:10.383: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
*Mar 1 00:32:11.223: EIGRP: Received HELLO on Ethernet0 nbr 10.1.1.1
*Mar 1 00:32:11.227: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
*Mar 1 00:32:11.379: EIGRP: Sending HELLO on Serial1
*Mar 1 00:32:11.383: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0
r3-2514#un all
All possible debugging has been turned off
r3-2514#
*Mar 1 00:32:12.759: EIGRP: Received HELLO on Serial1 nbr 10.1.3.4
*Mar 1 00:32:12.763: AS 1, Flags 0×0, Seq 0/0 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0
路由器一旦接到10.1.2.4发来的HELLO就返回一个那样的提示信息出来,看上面的蓝色部分.
另外从这个上面也可以看出HELLO消息在以太网链路上是5秒一次,在这个全互连帧中继线路上也是5秒一次.
[原创]BSCI第二章实验(人邮自学指南BSCI)
环境及拓扑图说明请参看[原创]BSCI第一章实验2之任务2(人邮自学指南BSCI)里的说明
本次实验目的主要是研究RIP V1 V2下路由选择的特性.
任务一:清除配置,这个没什么可多说的,主要是删除P1R1 P1 R2上的默认路由.
任务二:在P1R1/R2/R3/R4上启用RIP V1,这个也比较简单,注意书上要求 R1/2/3/4都显式申明使用V1,最终路由器的路由表如下:
P1R1:
r1-2514#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
C 1.0.0.0/8 is directly connected, Loopback0
172.31.0.0/24 is subnetted, 1 subnets
C 172.31.1.0 is directly connected, Serial0
10.0.0.0/24 is subnetted, 4 subnets
R 10.1.3.0 [120/1] via 10.1.1.3, 00:00:04, Ethernet0
R 10.1.2.0 [120/1] via 10.1.0.2, 00:00:20, Serial1
C 10.1.1.0 is directly connected, Ethernet0
C 10.1.0.0 is directly connected, Serial1
P1R3:
r3-2514#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
C 3.0.0.0/8 is directly connected, Loopback0
R 172.31.0.0/16 [120/1] via 10.1.1.1, 00:00:00, Ethernet0
10.0.0.0/24 is subnetted, 4 subnets
C 10.1.3.0 is directly connected, Serial1
R 10.1.2.0 [120/1] via 10.1.3.4, 00:00:02, Serial1
C 10.1.1.0 is directly connected, Ethernet0
R 10.1.0.0 [120/1] via 10.1.1.1, 00:00:00, Ethernet0
从P1R3 ping 10.254.0.5的结果是:
*Mar 1 01:37:59.951: IP: s=10.1.1.3 (local), d=10.254.0.5, len 100, unroutable.
*Mar 1 01:38:01.951: IP: s=10.1.1.3 (local), d=10.254.0.5, len 100, unroutable.
很显然不可能PING通,调试结果表明路由器没有到达10.254.0.5的路由条目,为什么会没有呢?
在上面的配置中,我们启用的是RIP V1版本,这是个分类路由选择协议,在跨越网络边界的时候,路由器会自动汇总成主类网络,所以说BBR1路由器,也就是我们这里的R5路由器的E0口所属的10.254.0.0/24网络,再通告道P1R1时候被自动汇总了成了10.0.0.0/8,所以P1R1不会有具体的10.254.0.0/24这个条目了,而只有红色的那部分.同时RIP V1,当路由器没有跨越网络边界通告路由时候,路由器会用自己接道更新的接口所属网络分类的掩码来套用到更新上,因此这个时候必须注意同一主类下的子网必须使用统一相同的掩码,否则路由器就会套用错误,本实验掩码都是255.255.255.0所以路由器套用正确,可以正确认识象10.1.1.0/ 10.1.2.0 /10.1.3.0/ 10.1.0.0这样的子网,请看上面的蓝色部分.
好了,上面总结下来就是路由器没有到目标网络的路由,那么书上在此步骤中提出了使用default-information originate注入一条静态路由,这个命令的作用其实就是向直连的其他路由器中注入一条通过自己的静态路由(是向其他人的路由表里注入,自己的路由表里不会有),但是我们这个实验环境由于网夹1里的路由器构成了一个环路,当P1R1启用该命令后,自己的路由表里也会有静态路由产生,^_^,为什么会有大家自己思考吧(观察R1上的静态路由,会发现,静态路由不停的变,一会通过这个口 一会通过那个口,而且度量值也在不停的变,仔细观察的话,还会发现有的条目会到最大跳数,为什么会不停的变,可以结合RIP的水平分割来理解下.这个地方很有趣),由于静态路由不停的翻动,就算是碰巧当前默认路由走的路径是对的话,也可以这么说如果按照书上的先关闭ip classless的话,还是PING不通,为什么?因为在关闭ip classless时候,在分类路由协议情况下,路由器如果首先发现有匹配的主类网络存在,那么路由器就会很笨的认为它知道了该主类网络下的所有子网,路由器此时不再会通过默认路由发送数据包,当然如果没有首先发现有主类存在那就会通过默认路由的.
任务三:
在任务三中,书上打开了IP classless特性,由于上面我说,默认路由在我们这个有环路的实验环境下,很难遇到当前每个路由器的默认路由走的路正好是从r3–r1–r5这一顺序,我在多次测试PING的情况下才遇到了一次返回U提示的(返回U提示表示PING包有路径出去了,但没接到返回包,也就是路由不可达了.)
r3-2514#ping 10.254.0.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.254.0.5, timeout is 2 seconds:
…U.
Success rate is 0 percent (0/5)
那么为什么这个时候数据包有去的路径没回的路径呢?分析BBR1,BBR1路由器上不会有10.1.1.0/24这样的具体网络,如下
r5-2501#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is 172.31.1.1 to network 0.0.0.0
C 5.0.0.0/8 is directly connected, Loopback0
172.31.0
.0/24 is subnetted, 1 subn
ets
C 172.31.1.0 is directly connected, Serial0
10.0.0.0/24 is subnetted, 1 subnets
C 10.254.0.0 is directly connected, Ethernet0
R* 0.0.0.0/0 [120/7] via 172.31.1.1, 00:00:00, Serial0
因为从P1R1过来的路由更新是跨网络的,刚才上面说了 跨网络时候RIP是要自动汇总成主类的,就汇成10.0.0.0/8了,而BBR1的e0口分配的地址是10.254.0.5 BBR1路由器会认为10.0.0.0/8网络是个直连网络,所以路由器BBR1不知道将返回信息送到哪,这里有人会问,不是有默认路由了吗??对是有,但是刚才上面说了,分类路由在主类一旦存在的情况下是不会去找默认路由的,就算没有子网能匹配它也不找,丢弃.
总结上面,看来静态路由/打开ip classless特性 由于分类路由的本身特性限制,都不能PING通,看来只有启用分类路由了,启用RIPV2了.
这里我来一步一步起,先起用V2 但不不关闭自动汇总看是什么情况.如下,P1R1的路由表:
r1-2514#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is 172.31.1.2 to network 0.0.0.0
C 1.0.0.0/8 is directly connected, Loopback0
172.31.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.31.1.0/24 is directly connected, Serial0
R 172.31.0.0/16 [120/1] via 10.1.0.2, 00:00:20, Serial1
10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
R 10.1.3.0/24 [120/1] via 10.1.1.3, 00:00:00, Ethernet0
R 10.1.2.0/24 [120/1] via 10.1.0.2, 00:00:20, Serial1
C 10.1.1.0/24 is directly connected, Ethernet0
R 10.0.0.0/8 [120/1] via 172.31.1.2, 00:00:01, Serial0
C 10.1.0.0/24 is directly connected, Serial1
R* 0.0.0.0/0 [120/10] via 172.31.1.2, 00:01:42, Serial0
[120/10] via 172.31.1.5, 00:01:42, Serial0
[120/10] via 10.1.0.2, 00:00:21, Serial1
注意看红色斜体部门和蓝色斜体部分,注意看到路由表里不但存在有主类下下的具体子网条目还有一个汇总过的主类条目,这个汇总的是哪来的?分析下就知道172.31.0.0/16这个通过的接口是10.1.0.2 所以是172.31.1.0/24这个网络通过P1R2跨主网络汇总给P1R1的,10.0.0.0/8是通过接口172.31.1.2 且跳数是1(呵呵这里看好像不太合理,其实多显示几次陆游表就又发现了,这里还是一个环路网络,10.0.0.0/8这个跳数不停的变.),这说明BBR的10网络还是被自动汇总过来.此时来PING10.254.0.5同样是…..不通.可以看出由于此时还是没有关闭自动汇总功能,路由器还是没有到10.254.0.0/24网络的路由,不过这里有个疑问,此时是无类路由协议了,且打开了ip classless
特性,应该说有默认路由的存在网络应该能PING通,就算本实验的默认路由会不停的变,但多PING一些 应该会有通的可能,但实际测试PING 100个包没有一个通的,可能是没有关闭自动汇总功能,路由器还是向分类路由一样,不去找默认路由吧.
再关闭自动汇总看这个时候情况如何(实验中注意这个时候,BBR路由器还没启用V2).
在关闭自动汇总后,BBR1上便出现了具体的子网:
r5-2501#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
C 5.0.0.0/8 is directly connected, Loopback0
172.31.0.0/24 is subnetted, 1 subnets
C 172.31.1.0 is directly connected, Serial0
10.0.0.0/24 is subnetted, 5 subnets
R 10.1.3.0 [120/2] via 172.31.1.1, 00:02:21, Serial0
[120/2] via 172.31.1.2, 00:01:56, Serial0
R 10.1.2.0 [120/1] via 172.31.1.2, 00:01:56, Serial0
R 10.1.1.0 [120/1] via 172.31.1.1, 00:02:21, Serial0
R 10.1.0.0 [120/1] via 172.31.1.1, 00:02:21, Serial0
[120/1] via 172.31.1.2, 00:01:57, Serial0
C 10.254.0.0 is directly connected, Ethernet0
而此时由于BBR1自己还没启V2,可以看到在P1R3路由器上还有10.0.0.0/8这个汇总路由,:
r3-2514#show ip route
Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route
Gateway of last resort is not set
C 3.0.0.0/8 is directly connected, Loopback0
172.31.0.0/24 is subnetted, 1 subnets
R 172.31.1.0 [120/1] via 10.1.1.1, 00:00:26, Ethernet0
10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
C 10.1.3.0/24 is directly connected, Serial1
R 10.1.2.0/24 [120/1] via 10.1.3.4, 00:00:01, Serial1
C 10.1.1.0/24 is directly connected, Ethernet0
R 10.0.0.0/8 [120/2] via 10.1.1.1, 00:00:26, Ethernet0
R 10.1.0.0/24 [120/1] via 10.1.1.1, 00:00:26, Ethernet0
此时PING 10.254.0.5 还是
不通,为什么因为还是没有具体的匹配路由.(这里有个小插曲,大家注意看上面这2个陆游表都没了默认路由了,其实是我关闭了默认路由,经过测试,在存在默认路由情况下,路由器会返回U这个提示,表示有去无回,说明在启用V2后,没有关闭自动汇总功能的路由器上,路由行为还是如同分类路由RIPV1一样,不去寻找默认路由.)
从上面可以看出,此时要想能PING通10.254.0.5就必须让路由器P1R3上有到10.254.0.0/24这个具体条目,因此在BBR1上开启V2.并关闭自动汇总功能.实践证明,这样操作后,PING通了,见下面R3上路由表及PING结果:
Gateway of last resort is 10.1.1.1 to network 0.0.0.0
C 3.0.0.0/8 is directly connected, Loopback0
172.31.0.0/24 is subnetted, 1 subnets
R 172.31.1.0 [120/1] via 10.1.1.1, 00:00:09, Ethernet0
10.0.0.0/24 is subnetted, 5 subnets
C 10.1.3.0 is directly connected, Serial1
R 10.1.2.0 [120/1] via 10.1.3.4, 00:00:01, Serial1
C 10.1.1.0 is directly connected, Ethernet0
R 10.1.0.0 [120/1] via 10.1.1.1, 00:00:09, Ethernet0
R 10.254.0.0 [120/2] via 10.1.1.1, 00:00:09, Ethernet0
R* 0.0.0.0/0 [120/1] via 10.1.1.1, 00:00:10, Ethernet0
r3-2514#ping 10.254.0.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.254.0.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 36/39/44 ms