排除IS-IS邻接问题
简介
本文档介绍如何对Cisco IOS® XE平台的IS-IS协议进行故障排除。
先决条件
要求
Cisco 建议您了解以下主题：
- 中间系统到中间系统(IS-IS)
- 思科IOS XE
有关这些主题的详细信息，请参阅：
使用的组件
本文档中的信息基于Cisco IOS XE软件。
本文档中的信息都是基于特定实验室环境中的设备编写的。本文档中使用的所有设备最初均采用原始（默认）配置。如果您的网络处于活动状态，请确保您了解所有命令的潜在影响。
IS-IS邻接断开
本节提供解决IS-IS关闭这一常见问题的方法。此网络图用作示例：
基线拓扑
IS-IS在DeviceA和DeviceB之间关闭。
DeviceA#show isis neighbors detail System Id Type Interface IP Address State Holdtime Circuit Id DeviceA#
DeviceB#show isis neighbors detail System Id Type Interface IP Address State Holdtime Circuit Id DeviceA L1L2 Twe1/0/9 192.0.2.1 DOWN 28 05 Area Address(es): 49.0001 SNPA: a84f.b1c3.9484 State Changed: never Format: Phase V Remote TID: 0 Local TID: 0 Interface name: TwentyFiveGigE1/0/9 Neighbor Circuit Id: 5 Adj sync: Full
诊断问题:
1.验证设备之间的连通性。
DeviceA#ping 192.0.2.2 size 1500 df-bit Type escape sequence to abort. Sending 5, 1500-byte ICMP Echos to 192.0.2.2, timeout is 2 seconds: Packet sent with the DF bit set !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms DeviceA#
DeviceB#ping 192.0.2.1 size 1500 df-bit Type escape sequence to abort. Sending 5, 1500-byte ICMP Echos to 192.0.2.1, timeout is 2 seconds: Packet sent with the DF bit set !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms DeviceB#
2.检查两端的配置。
DeviceA#show running-config | sec router isis ip router isis router isis net 49.0001.0000.0000.000a.00 DeviceA#
DeviceB#show running-config | sec router isis ip router isis router isis net 49.0001.0000.0000.000b.00 DeviceB#
3.验证邻接关系是否在 无连接网络服务(CLNS)。这会提供连接到设备的邻居的摘要。
DeviceA#show clns neighbors detail System Id Interface SNPA State Holdtime Type Protocol 0000.0000.000B Te0/0/4 6c31.0edb.3b5f Up 257 IS ES-IS Area Address(es): 49.0001 Uptime: 02:02:11 Interface name: TenGigabitEthernet0/0/4 DeviceA#
DeviceB#show clns neighbors detail System Id Interface SNPA State Holdtime Type Protocol 0000.0000.000A Twe1/0/9 a84f.b1c3.9484 Down 20 L1L2 IS-IS Area Address(es): 49.0001 IP Address(es): 192.0.2.1* Uptime: 02:02:09 NSF capable Interface name: TwentyFiveGigE1/0/9 DeviceB#
每个CLNS邻居上列出的MAC地址是与本地设备对等连接的远程设备的MAC地址。
DeviceA#show interface TenGigabitEthernet0/0/4
TenGigabitEthernet0/0/4 is up, line protocol is up
Hardware is 8xSFP+, address is a84f.b1c3.9484 (bia a84f.b1c3.9484) < mac address appeared on SNPA DeviceB
Internet address is 192.0.2.1/30
MTU 1500 bytes, BW 10000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
DeviceB#show interface TwentyFiveGigE1/0/9
TwentyFiveGigE1/0/9 is up, line protocol is up (connected)
Hardware is Twenty Five Gigabit Ethernet, address is 6c31.0edb.3b5f (bia 6c31.0edb.3b5f) < mac address appeared on SNPA DeviceA
Internet address is 192.0.2.2/30
MTU 9216 bytes, BW 10000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
4.运行命令 show clns interface
以验证参数是否与对等体匹配。
确保匹配以下值：
- 最大传输单位 (MTU)
- 电路类型
| 设备A |
DeviceA#show clns interface TenGigabitEthernet0/0/4 |
| 设备B |
DeviceB#show clns interface TwentyFiveGigE1/0/9 |
在此场景中，问题与MTU不匹配有关。如果无法访问远程对等体， debug isis adj-packets
可以显示正在发送和接收的MTU值。
注：仅当该命令出现时，此命令才适用 show clns interface打印 if state INIT.
DeviceA#debug isis adj-packets TenGigabitEthernet 0/0/4
IS-IS Adjacency related packets debugging is on for router process null
*Jul 18 23:24:16.598: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5
*Jul 18 23:24:16.599: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496 < MTU sent to the neighbor >
*Jul 18 23:24:25.189: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5
*Jul 18 23:24:25.189: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496
*Jul 18 23:24:34.057: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5
*Jul 18 23:24:34.057: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496
*Jul 18 23:24:42.866: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5
*Jul 18 23:24:42.866: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496
*Jul 18 23:24:51.646: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5
*Jul 18 23:24:51.646: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496
*Jul 18 23:24:59.606: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5
*Jul 18 23:24:59.606: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496
DeviceB#debug isis adj-packets twentyFiveGigE 1/0/9
*Jul 18 23:53:22.420: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:INIT, length 9212 < MTU sent to the neighbor >
*Jul 18 23:53:22.591: ISIS-Adj: Rec serial IIH from a84f.b1c3.9484 (TwentyFiveGigE1/0/9)
*Jul 18 23:53:22.591: ISIS-Adj: cir type L1L2, cir id 05, length 1496 < MTU received from neighbor >
*Jul 18 23:53:22.592: ISIS-Adj: rcvd state DOWN, old state INIT, new state INIT, nbr usable TRUE
*Jul 18 23:53:22.592: ISIS-Adj: RCV:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x49000184 Length:5
*Jul 18 23:53:22.592: ISIS-Adj: Nghbr Ckt ID changed: FALSE
*Jul 18 23:53:22.592: ISIS-Adj: newstate:1, state_changed:0, going_up:0, going_down:0
*Jul 18 23:53:22.592: ISIS-Adj: Action = ACCEPT
*Jul 18 23:53:22.592: ISIS-Adj: ACTION_ACCEPT:
...
ISIS邻接关系断开（与MTU不匹配无关）
IS-IS关闭，且接口上的MTU匹配。
DeviceA#show clns neighbors System Id Interface SNPA State Holdtime Type Protocol DeviceA#
DeviceB#show clns neighbors System Id Interface SNPA State Holdtime Type Protocol DeviceB#
- 验证与对等体匹配的配置。
- 确保物理接口处于正常传输状态（无错误或信号电平问题）。
- 检查对等体之间的连接（ping测试添加MTU大小和df-bit）。
- 验证对等体之间的CLNS邻居。
- 确保两端的MTU和电路类型与状态相同。
| 设备A |
DeviceA#show clns interface TenGigabitEthernet 0/0/4 |
| 设备B |
DeviceB#show clns interface twentyFiveGigE 1/0/9 |
6.启用 debug isis adj-packet
并验证发送和接收的数据包。
DeviceA#debug isis adj-packets TenGigabitEthernet 0/0/4
IS-IS Adjacency related packets debugging is on for router process null *Jul 19 13:32:52.788: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5 *Jul 19 13:32:52.788: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496 *Jul 19 13:33:00.708: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5 *Jul 19 13:33:00.709: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496 *Jul 19 13:33:09.726: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5 *Jul 19 13:33:09.726: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496 *Jul 19 13:33:18.376: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5 *Jul 19 13:33:18.376: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496 *Jul 19 13:33:26.132: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5 *Jul 19 13:33:26.132: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496 DeviceA#
DeviceB#debug isis adj-packets TwentyFiveGigE1/0/9 IS-IS Adjacency related packets debugging is on for router process null *Jul 19 14:01:32.125: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x0 Length:5 *Jul 19 14:01:32.125: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:DOWN, length 1496 *Jul 19 14:01:40.005: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x0 Length:5 *Jul 19 14:01:40.005: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:DOWN, length 1496 *Jul 19 14:01:49.602: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x0 Length:5 *Jul 19 14:01:49.602: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:DOWN, length 1496 *Jul 19 14:01:58.284: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x0 Length:5 *Jul 19 14:01:58.284: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:DOWN, length 1496
两台设备都在发送，但是它们没有收到来自邻居的Hello数据包。
7.启用捕获，以验证数据包是否已发送到每个邻居。捕获完成后，将其导出到bootflash或flash作为.pcap file
DeviceA#show monitor cap cap parameter
monitor capture cap interface TenGigabitEthernet0/0/4 BOTH < Interface from where send and receive the Hello Packets >
monitor capture cap control-plane IN < Packets to be process and generated by the CPU >
monitor capture cap access-list TAC < ACL for capture only the IS-IS packets >
monitor capture cap buffer size 10
monitor capture cap limit pps 1000
DeviceA#show access-list TAC
Extended MAC access list TAC
permit host a84f.b1c3.9484 host 0900.2b00.0005 < Local MAC address towards the IS-IS Hello >
permit host 6c31.0edb.3b5f host 0900.2b00.0005 < Remote MAC address towards the IS-IS Hello >
DeviceB#show monitor capture cap parameter monitor capture cap interface TwentyFiveGigE1/0/9 BOTH < Interface from where send and receive the Hello Packets > monitor capture cap control-plane BOTH < Packets to be process and generated by the CPU > monitor capture cap match any < match all the packets on the switch > monitor capture cap buffer size 10
注意:Catalyst Cisco IOS XE交换机的EPC仅捕获传出IS-IS问询，而不捕获入口数据包。作为替代方法，建议使用SPAN捕获。
下表中显示了对Hello数据包的引用。
| 名称 | 目的 MAC 地址 |
| 所有L1 IS | 0180.c200.0014 |
| 所有L2 IS | 0180.c200.0015 |
| 所有IS | 0900.2b00.0005 |
| 所有ES | 0900.2b00.0004 |
8.检查导出的捕获并确保邻居之间交换hello数据包。
设备A发送hello数据包，添加其系统ID（红方块）。预期会收到其邻居发来的带有其系统ID的数据包。在此捕获中，您可以了解到DeviceB不会将这些数据包转发给对等体。
设备A ISIS已关闭捕获
DeviceB捕获显示hello数据包已发送到其邻居（红方形）。但是，与上次捕获类似，它不会收到来自邻居的Hello数据包。
DeviceB ISIS关闭捕获
此场景中的问题是由于中间设备不允许发送hello数据包。如果您观察到类似情况并需要进一步排除故障，请打开Cisco TAC案例。
IS-IS邻接不稳定
本节提供解决IS-IS襟翼常见问题的方法。
诊断问题:
IS-IS在设备A和设备B之间不稳定。
DeviceA#show logging
Jul 19 15:05:03.623: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Down, hold time expired
Jul 19 15:05:15.075: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Up, new adjacency
Jul 19 15:07:04.575: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Down, hold time expired
Jul 19 15:07:15.759: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Up, new adjacency
Jul 19 15:09:04.983: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Down, hold time expired
Jul 19 15:09:14.835: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Up, new adjacency
DeviceB#show logging
Jul 19 15:05:02.316: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Down, hold time expired
Jul 19 15:05:18.191: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Up, new adjacency
Jul 19 15:07:09.280: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Down, hold time expired
Jul 19 15:07:18.876: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Up, new adjacency
Jul 19 15:09:06.080: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Down, hold time expired!
Jul 19 15:09:17.948: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Up, new adjacency
1.检查对等体之间的连接（使用MTU大小和df-bit设置执行ping测试）。
2.确保物理接口处于良好的传输状态（无错误或信号电平问题）。
3.使用命令验证CLNS邻居相互发送流量 show clns traffic interface
.
DeviceA#show clns traffic interface TenGigabitEthernet0/0/4 CLNS: Time since last clear: 00:01:57 CLNS & ESIS Output: 3, Input: 21 Dropped Protocol not enabled on interface: 0 CLNS Local: 0, Forward: 0
Interface TenGigabitEthernet0/0/4: IS-IS: Time since last clear: 00:01:57 IS-IS: Level-1 Hellos (sent/rcvd): 0/0 IS-IS: Level-2 Hellos (sent/rcvd): 0/0 IS-IS: PTP Hellos (sent/rcvd): 15/11 < DeviceA sends hello packets and receives less than its sends> IS-IS: Level-1 LSPs flooded (sent/rcvd): 2/2 IS-IS: Level-2 LSPs flooded (sent/rcvd): 2/2 IS-IS: Level-1 CSNPs (sent/rcvd): 1/1 IS-IS: Level-2 CSNPs (sent/rcvd): 1/1 IS-IS: Level-1 PSNPs (sent/rcvd): 1/1 IS-IS: Level-2 PSNPs (sent/rcvd): 1/1 IS-IS: Level-1 DR Elections: 0 IS-IS: Level-2 DR Elections: 0
DeviceB#show clns traffic interface TwentyFiveGigE1/0/9
CLNS: Time since last clear: 00:00:27
CLNS queue depth: 0/100, drops: 0, highest: 2
CLNS & ESIS Output: 1, Input: 14
Dropped Protocol not enabled on interface: 0
CLNS Local: 0, Forward: 0
提示：命令 clns traffic 根据IS-IS级别和IS-IS网络类型显示IS-IS Hello。
4.启用 debug ISIS adj-packets
以便查看邻居之间交换的数据包。
DeviceA#show isis adj-packets TenGigabitEthernet0/0/4 < Hellos sent to the DeviceB with no response > Jul 19 18:58:34.779: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15 Jul 19 18:58:34.779: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496 Jul 19 18:58:42.719: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15 Jul 19 18:58:42.719: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496 Jul 19 18:58:50.430: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15 Jul 19 18:58:50.430: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496 Jul 19 18:58:58.356: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15 Jul 19 18:58:58.356: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496 < IS-IS declares the protocol down > Jul 19 18:59:01.879: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Down, hold time expired < IS-IS sends hellos to the neighbor and receives a response from DeviceB > Jul 19 18:59:01.879: ISIS-Adj: L2 adj count 0 Jul 19 18:59:07.724: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5 Jul 19 18:59:07.724: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496 Jul 19 18:59:15.894: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x0 Length:5 Jul 19 18:59:15.894: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:DOWN, length 1496 Jul 19 18:59:15.896: ISIS-Adj: Rec serial IIH from 6c31.0edb.3b5f (TenGigabitEthernet0/0/4) Jul 19 18:59:15.896: ISIS-Adj: cir type L2, cir id 0B, length 1496 Jul 19 18:59:15.896: ISIS-Adj: RCV:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15 Jul 19 18:59:15.896: ISIS-Adj: Nghbr Ckt ID changed: TRUE Jul 19 18:59:15.896: ISIS-Adj: received Neighbor System-ID (must be our) 0000.0000.000A Jul 19 18:59:15.896: ISIS-Adj: received Neighbor ext.circuit ID (must be our) 0x5 Jul 19 18:59:15.896: ISIS-Adj: newstate:1, state_changed:1, going_up:0, going_down:0 Jul 19 18:59:15.896: ISIS-Adj: Action = GOING UP, new type = L2 < DeviceA declares that the adjacency is UP and starts to establish the session > Jul 19 18:59:15.896: ISIS-Adj: New serial adjacency Jul 19 18:59:15.896: ISIS-Adj: rcvd state INIT, old state DOWN, new state INIT, nbr usable TRUE Jul 19 18:59:15.898: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15 Jul 19 18:59:15.898: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:INIT, length 1496 Jul 19 18:59:15.900: ISIS-Adj: Rec serial IIH from 6c31.0edb.3b5f (TenGigabitEthernet0/0/4) Jul 19 18:59:15.900: ISIS-Adj: cir type L2, cir id 0B, length 1496 Jul 19 18:59:15.900: ISIS-Adj: rcvd state UP, old state INIT, new state UP, nbr usable TRUE Jul 19 18:59:15.900: ISIS-Adj: RCV:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15 Jul 19 18:59:15.900: ISIS-Adj: Nghbr Ckt ID changed: FALSE Jul 19 18:59:15.900: ISIS-Adj: received Neighbor System-ID (must be our) 0000.0000.000A Jul 19 18:59:15.900: ISIS-Adj: received Neighbor ext.circuit ID (must be our) 0x5 Jul 19 18:59:15.900: ISIS-Adj: newstate:0, state_changed:1, going_up:1, going_down:0 Jul 19 18:59:15.900: ISIS-Adj: Action = GOING UP, new type = L2 Jul 19 18:59:15.900: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Up, new adjacency
DeviceB#debug isis adj-packets TwentyFiveGigE1/0/9 < Hello sent to the DeviceA with no response > Jul 19 18:58:44.105: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15 Jul 19 18:58:44.105: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:UP, length 1496 Jul 19 18:58:51.814: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15 Jul 19 18:58:51.814: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:UP, length 1496 Jul 19 18:58:59.768: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15 Jul 19 18:58:59.768: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:UP, length 1496 < IS-IS declares the protocol down > Jul 19 18:59:07.886: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Down, hold time expired
< IS-IS sends hellos to the neighbor and receives a response from DeviceA >
Jul 19 18:59:07.887: ISIS-Adj: L2 adj count 0 Jul 19 18:59:08.422: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x0 Length:5 Jul 19 18:59:08.422: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:DOWN, length 1496 Jul 19 18:59:16.144: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x0 Length:5 Jul 19 18:59:16.144: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:DOWN, length 1496 Jul 19 18:59:19.001: ISIS-Adj: Rec serial IIH from a84f.b1c3.9484 (TwentyFiveGigE1/0/9) Jul 19 18:59:19.001: ISIS-Adj: cir type L2, cir id 05, length 1496 Jul 19 18:59:19.001: ISIS-Adj: RCV:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0x49000184 Length:5 Jul 19 18:59:19.001: ISIS-Adj: Nghbr Ckt ID changed: TRUE Jul 19 18:59:19.001: ISIS-Adj: newstate:1, state_changed:1, going_up:0, going_down:0 Jul 19 18:59:19.001: ISIS-Adj: Action = GOING UP, new type = L2 < DeviceB declares that the adjacency is UP and starts to establish the session > Jul 19 18:59:19.001: ISIS-Adj: New serial adjacency Jul 19 18:59:19.001: ISIS-Adj: rcvd state DOWN, old state DOWN, new state INIT, nbr usable TRUE Jul 19 18:59:19.002: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15 Jul 19 18:59:19.002: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:INIT, length 1496 Jul 19 18:59:19.004: ISIS-Adj: Rec serial IIH from a84f.b1c3.9484 (TwentyFiveGigE1/0/9) Jul 19 18:59:19.004: ISIS-Adj: cir type L2, cir id 05, length 1496 Jul 19 18:59:19.004: ISIS-Adj: rcvd state INIT, old state INIT, new state UP, nbr usable TRUE Jul 19 18:59:19.004: ISIS-Adj: RCV:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15 Jul 19 18:59:19.004: ISIS-Adj: Nghbr Ckt ID changed: FALSE Jul 19 18:59:19.004: ISIS-Adj: received Neighbor System-ID (must be our) 0000.0000.000B Jul 19 18:59:19.004: ISIS-Adj: received Neighbor ext.circuit ID (must be our) 0xB Jul 19 18:59:19.004: ISIS-Adj: newstate:0, state_changed:1, going_up:1, going_down:0 Jul 19 18:59:19.004: ISIS-Adj: Action = GOING UP, new type = L2 Jul 19 18:59:19.004: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Up, new adjacency
5.启用捕获，以验证数据包是否已发送到每个邻居。捕获完成后，将捕获导出到bootflash作为 .pcap file 并将其上传到TFTP服务器以了解更多详细信息。
收到此数据包后，设备A收到来自设备B(19:15.05)的数据包。设备A发送其相应的hello数据包，而邻居没有任何回复，直到其达到保持时间（默认情况下为30秒）（红方块）。
这时路由器会声明邻接关系已关闭。在此时间段之后，设备B发送其hello数据包并由DeviceA接收，这些数据包交换时没有问题（绿色方块）。
ISIS不稳定设备A
从设备B捕获类似于从对等设备捕获症状。设备不会收到来自其邻居的hello数据包。最后一个数据包从DeviceB发送，直到到达30秒保留计时器，才会从DeviceA收到应答。此交换机认为邻接关系已断开。发生此故障后，交换机收到来自DeviceA的hello并启动邻居关系。
ISIS不稳定设备B
传输问题到此结束，您必须检查数据包丢失的原因。
IS-IS邻接关系不稳定（随机摆动）
IS-IS在设备A和设备B之间不稳定。协议遇到随机摆动。
DeviceA#show logging Jul 21 10:03:38.633: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Down, hold time expired Jul 21 10:05:10.272: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Up, new adjacency Jul 21 10:33:41.528: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Down, hold time expired Jul 21 10:35:07.979: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Up, new adjacency Jul 21 11:03:42.442: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Down, hold time expired Jul 21 11:05:08.469: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Up, new adjacency
DeviceB#show logging Jul 21 10:03:44.535: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Down, hold time expired Jul 21 10:05:13.281: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Up, new adjacency Jul 21 10:33:38.408: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Down, hold time expired Jul 21 10:35:10.989: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Up, new adjacency Jul 21 11:03:39.291: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Down, hold time expired Jul 21 11:05:11.479: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Up, new adjacency
出现问题时，请确保继续执行以下操作：
- 验证配置是否与对等体匹配。
- 确保物理接口处于正常传输状态（无错误或信号电平问题）。
- 检查对等体之间的连接（使用MTU大小和df-bit设置执行ping测试）。
提示：由于存在随机摆动，因此很难解决此类问题。要解决此问题，请考虑使用脚本运行必要的命令并继续排除故障。
4.继续使用访问列表配置监控器捕获，以便更详细地了解故障排除过程。
5.禁用日志记录控制台，并启用 debug isis adj-packets
.
DeviceA(config)#no logging console DeviceA(config)#exit DeviceA#debug isis adj-packets TenGigabitEthernet0/0/4
6.在设备上启用数据包捕获并激活它。
DeviceA#show monitor capture cap parameter
monitor capture cap interface TenGigabitEthernet0/0/4 BOTH monitor capture cap control-plane IN monitor capture cap access-list TAC > match only the packets allowed on the ACL monitor capture cap buffer size 100 circular > when the capture reaches the size of 100 MB this overwrite the previous information. monitor capture cap limit pps 1000
DeviceA#show access-lists TAC Extended MAC access list TAC permit host a84f.b1c3.9484 host 0900.2b00.0005 < Local MAC address towards the IS-IS Hello > permit host 6c31.0edb.3b5f host 0900.2b00.0005 < Remote MAC address towards the IS-IS Hello >
DeviceA#monitor capture cap start
7.在思科设备上配置嵌入式事件管理器(EEM)。一旦问题触发系统日志模式，就会生成存储在闪存中的日志，作为 .txt 文件.有关详细信息，请继续将其上传到TFTP服务器。
DeviceA#show running-config | sec event event manager applet ISIS_Flap authorization bypass
event syslog pattern "%CLNS-5-ADJCHANGE:.*hold time expired"
action 1.0 syslog msg "ISIS down Please wait - capturing the traffic"
action 1.1 cli command "enable"
action 1.2 cli command "show clns interface ten0/0/4 | append bootflash:ISIS_DeviceA.txt"
action 1.3 cli command "show clns traffic interface tenGigabitEthernet 0/0/4 | append bootflash:ISIS_DeviceA.txt"
action 2.0 cli command "show logging | append bootflash:debug_DeviceA.txt"
action 2.1 cli command "undebug all"
action 2.2 cli command "monitor capture cap stop"
action 3.0 cli command "end"
For switches to append the logs it is neccesary to use the append flash:, as example:
event manager applet ISIS_Flap authorization bypass event syslog pattern "%CLNS-5-ADJCHANGE:.*hold time expired" action 1.0 syslog msg "ISIS down Please wait - capturing the traffic" action 1.1 cli command "enable" action 1.2 cli command "show clns interface ten0/0/4 | append flash:ISIS_DeviceB.txt"
action 3.0 cli command "end"
8.一旦问题触发，继续导出bootflash/flash上的捕获并确保 .txt 文件可正确存储在同一位置。
DeviceA#monitor capture cap export bootflash:ISIS_DeviceA.pcap Exported Successfully DeviceA#dir bootflash:*.txt Directory of bootflash:/*.txt Directory of bootflash:/ 19 -rw- 6048 Jul 22 2023 13:33:40 +00:00 ISIS_DeviceA.txt 20 -rw- 103153 Jul 22 2023 13:33:40 +00:00 debug_DeviceA.txt 26975526912 bytes total (20527607808 bytes free)
DeviceB#monitor capture cap export location flash:ISIS_DeviceB.pcap
Exported Successfully
DeviceB#dir bootflash:*.txt Directory of bootflash:/*.txt Directory of bootflash:/ 356939 -rw- 660 Jul 22 2023 13:33:42 +00:00 ISIS_DeviceB.txt 356943 -rw- 103283 Jul 22 2023 13:33:42 +00:00 debug_DeviceB.txt
9.将文件上传到TFTP服务器，以比较设备之间的日志。
DeviceA#copy bootflash:ISIS_DeviceA.txt tftp:
Address or name of remote host []? < TFTP IP address >
Destination filename [ISIS_DeviceA.txt]?
10.比较捕获和日志，以验证是否从两台路由器发送和接收数据包。
IS-IS日志分析：
- 两个IS-IS接口配置有相同的网络类型L1-L2。
- Interfaces状态（如果状态为DOWN）显示两个接口均未收到hello数据包。
- IS-IS:PTP Hello在发送和接收的数据包中存在不匹配。当设备A发送205个数据包并从对等设备接收199个数据包时，设备B有202个数据包（共202个）。这表示传输不可靠。
DeviceA
TenGigabitEthernet0/0/4 is up, line protocol is up Attached to: isis Checksums enabled, MTU 1497, Encapsulation SAP ERPDUs enabled, min. interval 10 msec. CLNS fast switching disabled CLNS SSE switching disabled DEC compatibility mode OFF for this interface Next ESH/ISH in 30 seconds Routing Protocol: IS-IS Circuit Type: level-1-2 Interface number 0x0, local circuit ID 0x5 Neighbor Extended Local Circuit ID: 0x0 Level-1 Metric: 10, Priority: 64, Circuit ID: DeviceA.05 Level-1 IPv6 Metric: 10 Number of active level-1 adjacencies: 0 Level-2 Metric: 10, Priority: 64, Circuit ID: DeviceA.05 Level-2 IPv6 Metric: 10 Number of active level-2 adjacencies: 0 Next IS-IS Hello in 574 milliseconds if state DOWN CLNS: Time since last clear: 00:29:37 CLNS & ESIS Output: 33, Input: 241 Dropped Protocol not enabled on interface: 0 CLNS Local: 0, Forward: 0
Interface TenGigabitEthernet0/0/4: IS-IS: Time since last clear: 00:29:37 IS-IS: Level-1 Hellos (sent/rcvd): 0/0 IS-IS: Level-2 Hellos (sent/rcvd): 0/0 IS-IS: PTP Hellos (sent/rcvd): 205/199 IS-IS: Level-1 LSPs flooded (sent/rcvd): 2/2 IS-IS: Level-2 LSPs flooded (sent/rcvd): 2/2 IS-IS: Level-1 CSNPs (sent/rcvd): 0/0 IS-IS: Level-2 CSNPs (sent/rcvd): 0/0 IS-IS: Level-1 PSNPs (sent/rcvd): 2/2 IS-IS: Level-2 PSNPs (sent/rcvd): 2/2 IS-IS: Level-1 DR Elections: 0 IS-IS: Level-2 DR Elections: 0 DeviceB TwentyFiveGigE1/0/9 is up, line protocol is up Attached to: isis Checksums enabled, MTU 1497, Encapsulation SAP ERPDUs enabled, min. interval 10 msec. CLNS fast switching disabled CLNS SSE switching disabled DEC compatibility mode OFF for this interface Next ESH/ISH in 20 seconds Routing Protocol: IS-IS Circuit Type: level-1-2 Interface number 0x0, local circuit ID 0xB Neighbor Extended Local Circuit ID: 0x0 P2P retransmit queue size: 0 Level-1 Metric: 10, Priority: 64, Circuit ID: DeviceB.0B Level-1 IPv6 Metric: 10 Number of active level-1 adjacencies: 0 Level-2 Metric: 10, Priority: 64, Circuit ID: DeviceB.0B Level-2 IPv6 Metric: 10 Number of active level-2 adjacencies: 0 Next IS-IS Hello in 7 seconds if state DOWN CLNS: Time since last clear: 00:29:34 CLNS queue depth: 0/100, drops: 0, highest: 1 CLNS & ESIS Output: 34, Input: 243 Dropped Protocol not enabled on interface: 0 CLNS Local: 0, Forward: 0
Interface TwentyFiveGigE1/0/9: IS-IS: Time since last clear: 00:29:34 IS-IS: Level-1 Hellos (sent/rcvd): 0/0 IS-IS: Level-2 Hellos (sent/rcvd): 0/0 IS-IS: PTP Hellos (sent/rcvd): 202/202 IS-IS: Level-1 LSPs flooded (sent/rcvd): 2/2 IS-IS: Level-2 LSPs flooded (sent/rcvd): 2/2 IS-IS: Level-1 CSNPs (sent/rcvd): 0/0 IS-IS: Level-2 CSNPs (sent/rcvd): 0/0 IS-IS: Level-1 PSNPs (sent/rcvd): 2/2 IS-IS: Level-2 PSNPs (sent/rcvd): 2/2 IS-IS: Level-1 DR Elections: 0 IS-IS: Level-2 DR Elections: 0
下一步是比较调试和捕获。
DeviceA
Jul 22 19:17:24.929: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15 Jul 22 19:17:24.929: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496 Jul 22 19:17:31.685: ISIS-Adj: Rec serial IIH from 6c31.0edb.3b5f (TenGigabitEthernet0/0/4) Jul 22 19:17:31.685: ISIS-Adj: cir type L1L2, cir id 0B, length 1496 Jul 22 19:17:31.685: ISIS-Adj: rcvd state UP, old state UP, new state UP, nbr usable TRUE Jul 22 19:17:31.685: ISIS-Adj: RCV:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15 Jul 22 19:17:31.685: ISIS-Adj: Nghbr Ckt ID changed: FALSE Jul 22 19:17:31.685: ISIS-Adj: received Neighbor System-ID (must be our) 0000.0000.000A Jul 22 19:17:31.685: ISIS-Adj: received Neighbor ext.circuit ID (must be our) 0x5 Jul 22 19:17:31.685: ISIS-Adj: newstate:0, state_changed:0, going_up:0, going_down:0 Jul 22 19:17:31.685: ISIS-Adj: Action = ACCEPT Jul 22 19:17:31.685: ISIS-Adj: ACTION_ACCEPT: Jul 22 19:17:33.626: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15 Jul 22 19:17:33.627: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496 Jul 22 19:17:42.671: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15 Jul 22 19:17:42.672: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496 Jul 22 19:17:52.008: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15 Jul 22 19:17:52.008: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496 Jul 22 19:18:01.475: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15 Jul 22 19:18:01.475: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496 Jul 22 19:18:01.685: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Down, hold time expired Jul 22 19:18:01.685: ISIS-Adj: L1 adj count 0 Jul 22 19:18:01.685: ISIS-Adj: L2 adj count 0
DeviceB
Jul 22 19:17:25.693: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15
Jul 22 19:17:25.693: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:UP, length 1496
Jul 22 19:17:27.882: ISIS-Adj: Rec serial IIH from a84f.b1c3.9484 (TwentyFiveGigE1/0/9)
Jul 22 19:17:27.882: ISIS-Adj: cir type L1L2, cir id 05, length 1496
Jul 22 19:17:27.882: ISIS-Adj: rcvd state UP, old state UP, new state UP, nbr usable TRUE
Jul 22 19:17:27.882: ISIS-Adj: RCV:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15
Jul 22 19:17:27.882: ISIS-Adj: Nghbr Ckt ID changed: FALSE
Jul 22 19:17:27.882: ISIS-Adj: received Neighbor System-ID (must be our) 0000.0000.000B
Jul 22 19:17:27.882: ISIS-Adj: received Neighbor ext.circuit ID (must be our) 0xB
Jul 22 19:17:27.882: ISIS-Adj: newstate:0, state_changed:0, going_up:0, going_down:0
Jul 22 19:17:27.882: ISIS-Adj: Action = ACCEPT
Jul 22 19:17:27.882: ISIS-Adj: ACTION_ACCEPT:
Jul 22 19:17:34.637: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15
Jul 22 19:17:34.637: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:UP, length 1496
Jul 22 19:17:36.579: ISIS-Adj: Rec serial IIH from a84f.b1c3.9484 (TwentyFiveGigE1/0/9)
Jul 22 19:17:36.579: ISIS-Adj: cir type L1L2, cir id 05, length 1496
Jul 22 19:17:36.579: ISIS-Adj: rcvd state UP, old state UP, new state UP, nbr usable TRUE
Jul 22 19:17:36.579: ISIS-Adj: RCV:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15
Jul 22 19:17:36.579: ISIS-Adj: Nghbr Ckt ID changed: FALSE
Jul 22 19:17:36.579: ISIS-Adj: received Neighbor System-ID (must be our) 0000.0000.000B
Jul 22 19:17:36.579: ISIS-Adj: received Neighbor ext.circuit ID (must be our) 0xB
Jul 22 19:17:36.579: ISIS-Adj: newstate:0, state_changed:0, going_up:0, going_down:0
Jul 22 19:17:36.579: ISIS-Adj: Action = ACCEPT
Jul 22 19:17:36.579: ISIS-Adj: ACTION_ACCEPT:
Jul 22 19:17:43.270: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15
Jul 22 19:17:43.271: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:UP, length 1496
Jul 22 19:17:51.658: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15
Jul 22 19:17:51.658: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:UP, length 1496
Jul 22 19:18:00.248: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15
Jul 22 19:18:00.248: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:UP, length 1496
Jul 22 19:18:06.579: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Down, hold time expired
Jul 22 19:18:06.579: ISIS-Adj: L1 adj count 0
Jul 22 19:18:06.579: ISIS-Adj: L2 adj count 0
IS-IS调试日志分析：
- 设备A发送hello数据包（7月22日19:17:24），设备B响应此数据包（7月22日19:17:25），设备A接收此响应（7月22日19:17:31）。
设备A
Jul 22 19:17:24.929: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15
Jul 22 19:17:24.929: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496
Jul 22 19:17:31.685: ISIS-Adj: Rec serial IIH from 6c31.0edb.3b5f (TenGigabitEthernet0/0/4)
设备B
Jul 22 19:17:25.693: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15
Jul 22 19:17:25.693: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:UP, length 1496
Jul 22 19:17:27.882: ISIS-Adj: Rec serial IIH from a84f.b1c3.9484 (TwentyFiveGigE1/0/9)
- 设备A发送另一个hello数据包(Jul 22 19:17:33)，设备B发送其hello数据包(Jul 22 19:17:34)，两秒钟后收到来自其对等体的数据包。
设备A
Jul 22 19:17:33.626: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15
Jul 22 19:17:33.627: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496
设备B
Jul 22 19:17:34.637: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15
Jul 22 19:17:34.637: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:UP, length 1496
Jul 22 19:17:36.579: ISIS-Adj: Rec serial IIH from a84f.b1c3.9484 (TwentyFiveGigE1/0/9)
- 在DeviceA未收到由DeviceB发送的数据包期间，协议会在30秒后声明自己已关闭。
设备A
Jul 22 19:17:42.671: ISIS-Adj: SND:3way Adj. Local Ckt ID:0x5 Nghbr Ckt ID:0xB Length:15
Jul 22 19:17:42.672: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496 Jul 22 19:18:01.475: ISIS-Adj: Sending serial IIH on TenGigabitEthernet0/0/4, 3way state:UP, length 1496
Jul 22 19:18:01.685: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceB (TenGigabitEthernet0/0/4) Down, hold time expired
- DeviceB没有收到来自其对等体的任何数据包。在默认保持时间段后，此协议声明其自身已关闭。
设备B
Jul 22 19:17:43.270: ISIS-Adj: SND:3way Adj. Local Ckt ID:0xB Nghbr Ckt ID:0x5 Length:15
Jul 22 19:17:43.271: ISIS-Adj: Sending serial IIH on TwentyFiveGigE1/0/9, 3way state:UP, length 1496
<snip>
Jul 22 19:18:06.579: %CLNS-5-ADJCHANGE: ISIS: Adjacency to DeviceA (TwentyFiveGigE1/0/9) Down, hold time expired
捕获分析：
DeviceA从DeviceB接收数据包，但此路由器从对等设备收到的最后一个数据包是分钟13:17.31。然后，设备A发送Hello数据包
无对等体响应。
ISIS随机襟翼设备A
DeviceB捕获显示类似情况，交换机从其对等设备收到最后一个hello数据包，但DeviceB开始发送其hello数据包，而没有响应。
ISIS不稳定设备B
在导出的捕获中，Hello数据包不会在对等体之间传输。此问题似乎出在传输上。
修订历史记录
| 版本 | 发布日期 | 备注 |
|---|---|---|
1.0 |
27-Jul-2023 |
初始版本 |
反馈