(1)在本端看邻居。
Router1#sh ip os nei
Neighbor ID Pri State &nbs p; Dead Time Address Interface
2.2.2.2 0 EXCHANGE/ - 00:00:38 192.168.0.1 ATM2/0.1
.Dec 1 12:15:35: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on ATM2/0.1 from EXCHANGE to DOWN, Neighbor Down: Too many
retransmissions
#freebeme评：不一会就ospf邻居就是down状态了。#
(2)首先我们在本地ping对端路由器的atm子接口地址。扩展ping，ping1000个包。
Router1#ping
Protocol [ip]:
Target IP address: 192.168.0.1
Repeat count [5]: 1000
Datagram size [100]:
Timeout in seconds [2]:
Extended commands [n]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 1000, 100-byte ICMP Echos to 192.168.0.1, timeout is 2 seconds:
.!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!
!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!
!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!
!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!
!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!
!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
.Dec 1 12:15:35: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on ATM2/0.1 from EXCHANGE to DOWN, Neighbor Down: Too many
retransmissions!!!!!!!!
!!!!!!!!!!!!!!!!!!!!
Success rate is 97 percent (976/1000), round-trip min/avg/max = 76/96/112 ms
Router1#
#明显，Down, Init, Attempt, 2-way, Exstart, Exchange, Loading 以及Full是ospf的几个
邻接状态。Exchange，是将要flooding的状态。现在看到，链路有问题，不足以维持
稳定的flooding。
(3)然后看看对端的接口是否起了ospf
Router2#sh ip os int brie
Interface PID Area IP Address/Mask Cost State Nbrs F/C
AT7/1/0.88 1 0 192.168.0.1/30 10 P2P 0/1
Lo0 152 0 2.2.2.2/32 1 LOOP 0/0
(4)在对端路由器看接口。
Router2#sh ip os int AT7/1/1.1
.Dec 1 11:54:04: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on ATM2/0.1 from DON to DOWN, Neighbor Down: Ignore timer expired52
ATM7/1/0.88 is up, line protocol is up
Internet Address 192.168.0.1/30, Area 6
Process ID 1, Router ID 2.2.2.2, Network Type POINT_TO_POINT, Cost: 651
Transmit Delay is 1 sec, State POINT_TO_POINT
Timer intervals configured, Hello 10,
oob-resync timeout 40
Hello due in 00:00:08
Supports Link-local Signaling (LLS)
Index 15/36, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 42
Last flood scan time is 0 msec, maximum is 4 msec
neighbor count is 0
Suppress hello for 0 neighbor(s)
(5)问题出在哪呢?
Router1#sh run int atm2/0.1
Building configuration...
Current configuration : 240 bytes
!
interface ATM2/0.1 point-to-point
description connect to Nenjiang R2 www.uptmd.com 15M
bandwidth 15360
ip address 10.10.253.142 255.255.255.252
pvc tobeijing 7/100
broadcast
encapsulation aal5snap
就是这里了。
查了查cisco文档。
http://www.cisco.com/en/US/tech/tk39/tk48/technologies_configuration_example09186a0080094570.shtml
这个里为了solves a communication problem 。使用了oam-pvc manage。
Router1#sh run int atm2/0.1
Building configuration...
Current configuration : 240 bytes
!
interface ATM2/0.1 point-to-point
description connect to Nenjiang R2 www.uptmd.com 15M
bandwidth 15360
ip address 10.10.253.142 255.255.255.252
pvc tobeijing 7/100
broadcast
oam-pvc manage
encapsulation aal5snap
我敲进去，md马上建立邻居了。。
Router1#sh ip os nei
Neighbor ID Pri State Dead Time Address Interface
