IS-IS 인접성 문제 해결

업데이트:2023년 7월 27일
문서 ID:220649

편견 없는 언어

본 제품에 대한 문서 세트는 편견 없는 언어를 사용하기 위해 노력합니다. 본 설명서 세트의 목적상, 편견 없는 언어는 나이, 장애, 성별, 인종 정체성, 민족 정체성, 성적 지향성, 사회 경제적 지위 및 교차성에 기초한 차별을 의미하지 않는 언어로 정의됩니다. 제품 소프트웨어의 사용자 인터페이스에서 하드코딩된 언어, RFP 설명서에 기초한 언어 또는 참조된 서드파티 제품에서 사용하는 언어로 인해 설명서에 예외가 있을 수 있습니다. 시스코에서 어떤 방식으로 포용적인 언어를 사용하고 있는지 자세히 알아보세요.

이 번역에 관하여

Cisco는 전 세계 사용자에게 다양한 언어로 지원 콘텐츠를 제공하기 위해 기계 번역 기술과 수작업 번역을 병행하여 이 문서를 번역했습니다. 아무리 품질이 높은 기계 번역이라도 전문 번역가의 번역 결과물만큼 정확하지는 않습니다. Cisco Systems, Inc.는 이 같은 번역에 대해 어떠한 책임도 지지 않으며 항상 원본 영문 문서(링크 제공됨)를 참조할 것을 권장합니다.


    소개

    이 문서에서는 Cisco IOS® XE 플랫폼용 IS-IS 프로토콜의 문제를 해결하는 방법을 설명합니다.

    사전 요구 사항

    요구 사항

    다음 주제에 대한 지식을 보유하고 있으면 유용합니다.

    • 중간 시스템에서 중간 시스템으로(IS-IS)
    • Cisco IOS XE

    이러한 항목에 대한 자세한 내용은 다음을 참조하십시오.

    사용되는 구성 요소

    이 문서의 정보는 Cisco IOS XE 소프트웨어를 기반으로 합니다.

    이 문서의 정보는 특정 랩 환경의 디바이스를 토대로 작성되었습니다. 이 문서에 사용된 모든 디바이스는 초기화된(기본) 컨피그레이션으로 시작되었습니다. 현재 네트워크가 작동 중인 경우 모든 명령의 잠재적인 영향을 미리 숙지하시기 바랍니다.

    IS-IS 인접성 중단


    이 섹션에서는 IS-IS 다운의 일반적인 문제에 대한 해결책을 제공합니다. 이 네트워크 다이어그램은 예시입니다:

    Baseline Topology기준 토폴로지

    IS-IS가 DeviceA와 DeviceB 사이에 있습니다.

    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

    문제 진단:

    1. 장치 간의 연결을 확인합니다.

    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. 양쪽의 구성을 검토합니다.

    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. 인접성이 CLNS(Connectionless Network Service). 디바이스에 연결된 네이버에 대한 요약을 제공합니다.

    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#

    각 CLNS 인접 디바이스에 나열된 mac 주소는 로컬 디바이스와 피어링하는 원격 디바이스의 mac 주소입니다.

    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. 명령을 실행합니다 show clns interface 매개변수가 피어와 일치하는지 확인하기 위해

    다음 값과 일치하는지 확인합니다.

    • 최대 전송 단위(MTU)
    • 회로 유형
    디바이스A 
    DeviceA#show clns interface TenGigabitEthernet0/0/4
    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 19 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 908 milliseconds
    if state DOWN
    장치B 
    DeviceB#show clns interface TwentyFiveGigE1/0/9 
    TwentyFiveGigE1/0/9 is up, line protocol is up
    Attached to: isis 
    Checksums enabled, MTU 9213, 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 8 seconds
    Routing Protocol: IS-IS
    Circuit Type: level-1-2
    Interface number 0x0, local circuit ID 0xB
    Neighbor Extended Local Circuit ID: 0x5
    Neighbor System-ID: 0000.0000.000A
    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 2 seconds
    if state INIT

    이 시나리오에서 문제는 MTU 불일치와 관련이 있습니다. 원격 피어에 액세스할 수 없는 경우 debug isis adj-packets 전송 및 수신되는 MTU 값을 표시할 수 있습니다.

    note-icon

    참고: 이는 명령이 실행되는 경우에만 적용됩니다 show clns interface인쇄 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 인접성 중단(MTU 불일치 관련 아님)


    IS-IS가 다운되고 인터페이스에서 MTU가 일치합니다.

    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#
    1. 피어와 일치하는 컨피그레이션을 확인합니다.
    2. 물리적 인터페이스가 전송 하기에 좋은 상태인지 확인합니다(오류 또는 조명 레벨 문제 없음).
    3. 피어 간의 연결을 확인합니다(MTU 크기 및 df 비트 추가 ping 테스트).
    4. 피어 간의 CLNS 네이버를 확인합니다.
    5. 양쪽 끝이 상태와 함께 동일한 MTU 및 동일한 Circuit-Type을 가지고 있는지 확인합니다.
    디바이스A 
    DeviceA#show clns interface TenGigabitEthernet 0/0/4
    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 41 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 2 seconds
    if state DOWN
    장치B 
    DeviceB#show clns interface twentyFiveGigE 1/0/9
    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 42 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 5 seconds
    if state DOWN

    6. 사용 debug isis adj-packet  전송 및 수신된 패킷을 검증합니다.

    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

    두 디바이스 모두 전송 중이지만 인접 디바이스로부터 Hello 패킷을 수신하지 않습니다.
    7. 각 네이버에 패킷이 전송되는지 확인하기 위해 캡처를 활성화합니다. 캡처가 완료되면 부트플래시 또는 플래시에.pcap file 자세한 내용을 보려면 TFTP 서버에 업로드하십시오.

    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
    note-icon

    참고: Catalyst Cisco IOS XE 스위치의 EPC는 발신 IS-IS Hello만 캡처하고 인그레스 패킷은 캡처하지 않습니다. 대안으로 SPAN 캡처를 사용하는 것이 좋습니다.


    이 표에서는 Hello 패킷에 대한 참조를 보여 줍니다.

    이름 대상 Mac 주소
    모든 L1 IS 0180.c200.0014
    모든 L2 IS 0180.c200.0015
    모든 IS 09,002억중국위안
    모든 ES 09,002b00.0004


    8. 내보낸 캡처를 검토하고 인접 디바이스 간에 hello 패킷이 교환되는지 확인합니다.

    DeviceA는 시스템 ID를 추가하여 hello 패킷을 전송합니다(빨간색 사각형). 시스템 ID를 사용하여 인접 디바이스로부터 패킷을 수신해야 합니다. 이 캡처에서는 DeviceB가 이러한 패킷을 피어로 전달하지 않음을 알 수 있습니다.


    DeviceA ISIS Down CaptureDeviceA ISIS 다운 캡처

    DeviceB 캡처는 hello 패킷이 네이버로 전송됨을 보여줍니다(빨간색 사각형). 그러나 마지막 캡처와 마찬가지로, 네이버에서 Hello 패킷을 수신하지 않습니다.


    DeviceB ISIS Down CaptureDeviceB ISIS 다운 캡처


    이 시나리오의 문제는 hello 패킷 전송을 허용하지 않는 중간 디바이스 때문입니다. 유사한 상황을 관찰하여 추가 트러블슈팅이 필요한 경우 Cisco TAC 케이스를 여십시오.

    IS-IS 인접성이 불안정함


    이 절에서는 IS-IS 플랩의 일반적인 문제에 대한 해결책을 제공합니다.

    문제 진단:

    IS-IS는 DeviceA와 DeviceB 간에 불안정합니다.

    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. 피어 간의 연결을 확인합니다(MTU 크기 및 df 비트가 설정된 ping 테스트).

    2. 물리적 인터페이스의 전송 상태가 양호한지 확인합니다(오류 또는 표시등 문제 없음).

    3. CLNS 인접 디바이스가 명령을 사용하여 트래픽을 서로 전송하는지 확인합니다 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

    
    
Interface TwentyFiveGigE1/0/9:
IS-IS: Time since last clear: 00:00:27
IS-IS: Level-1 Hellos (sent/rcvd): 0/0
IS-IS: Level-2 Hellos (sent/rcvd): 0/0
IS-IS: PTP Hellos     (sent/rcvd): 4/5  < DeviceB, sends and receives a couple of hellos in comparison with DeviceA>
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
    tip-icon

    팁: 명령 clns traffic is-IS 레벨 및 IS-IS 네트워크 유형을 기반으로 하는 IS-IS Hello를 표시합니다.

    4. 사용 debug ISIS adj-packets 인접 디바이스 간에 어떤 패킷이 교환되는지 확인하기 위해

    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. 패킷이 각 네이버로 전송되는지 검증하려면 캡처를 활성화합니다. 캡처가 완료되면 캡처를 부트플래시에 .pcap file 자세한 내용을 보려면 TFTP 서버에 업로드하십시오.

    DeviceA는 이 패킷을 수신한 후 DeviceB(19:15.05)로부터 패킷을 수신합니다. DeviceA는 기본적으로 30초(빨간색 사각형)로 만료된 보류 시간에 도달할 때까지 인접 디바이스의 응답 없이 해당 hello를 보냅니다.
    이 라우터가 인접성을 낮게 선언하는 경우입니다. 이 기간이 지나면 DeviceB가 hello를 전송하고 DeviceA에서 수신되며 이러한 패킷은 아무런 문제 없이 교환됩니다(녹색 사각형).


    ISIS unstable DeviceAISIS 불안정한 디바이스A

    DeviceB에서 캡처하는 것은 피어의 증상과 유사합니다. 디바이스는 인접 디바이스로부터 hello 패킷을 수신하지 않습니다. 마지막 패킷은 30초 보류 타이머에 도달할 때까지 DeviceB에서 DeviceA의 응답 없이 전송됩니다. 이 스위치는 인접성을 낮춘 것으로 간주합니다. 이 실패 후 스위치는 DeviceA로부터 hello를 수신하고 네이버십을 시작합니다.

    ISIS Unstable DeviceBISIS 불안정한 디바이스B


    이것으로 전송에 문제가 있으며 패킷이 손실되는 이유를 검토해야 합니다.

    IS-IS 인접성 불안정함(임의 플랩)

    IS-IS는 DeviceA와 DeviceB 간에 불안정합니다. 프로토콜에서 임의 플랩이 발생합니다.

    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

    문제가 발생하면 다음 작업을 진행해야 합니다.

    1. 컨피그레이션이 피어와 일치하는지 확인합니다.
    2. 물리적 인터페이스가 전송 하기에 좋은 상태인지 확인합니다(오류 또는 조명 레벨 문제 없음).
    3. 피어 간의 연결을 확인합니다(MTU 크기 및 df 비트가 설정된 ping 테스트).
    tip-icon

    팁: 무작위 플랩 상태로 인해 이러한 종류의 문제를 해결하는 것은 쉽지 않습니다. 이 상황을 해결하려면 스크립트를 사용하여 필요한 명령을 실행하고 트러블슈팅을 계속하십시오.

    4. 문제 해결에 대한 자세한 내용을 보려면 Access-list를 사용하여 모니터 캡처를 구성합니다.
    5. 로깅 콘솔을 비활성화하고 debug isis adj-packets .

    DeviceA(config)#no logging console            
DeviceA(config)#exit 
DeviceA#debug isis adj-packets TenGigabitEthernet0/0/4

    6. 장비에서 패킷 캡처를 활성화하고 활성화합니다.

    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. Cisco 장치에 EEM(Embedded Event Manager)을 구성합니다. 문제가 syslog 패턴을 트리거하면 플래시에 저장되는 로그가 .txt 파일을 클릭합니다. 자세한 내용을 보려면 계속해서 TFTP 서버에 업로드하십시오.

    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. 문제가 발생하면 bootflash/flash에서 캡처를 내보내고 .txt 파일은 동일한 위치에 올바르게 저장됩니다.

    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. 장치 간 로그를 비교하기 위해 TFTP 서버에 파일을 업로드합니다.

    DeviceA#copy bootflash:ISIS_DeviceA.txt tftp:
Address or name of remote host []? < TFTP IP address >
Destination filename [ISIS_DeviceA.txt]? 
    
    
!!
18144 bytes copied in 0.095 secs (190989 bytes/sec)

    10. 두 라우터에서 패킷이 전송 및 수신되는지 확인하기 위해 캡처와 로그를 비교합니다.

    IS-IS 로그 분석:

    • 두 IS-IS 인터페이스는 모두 동일한 네트워크 유형 L1-L2로 구성됩니다.
    • Interfaces 상태(DOWN 상태인 경우)는 두 인터페이스가 hello 패킷을 수신하지 않음을 보여줍니다.
    • IS-IS: PTP Hello에서 전송 및 수신된 패킷이 일치하지 않습니다. DeviceA가 205개의 패킷을 전송하고 피어에서 199개를 수신하는 동안 DeviceB는 202개 중 202개를 수신합니다. 이는 전송이 안정적이지 않음을 나타냅니다.
    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

    다음 단계는 디버그와 캡처를 비교하는 것입니다.

    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 디버그 로그 분석:

    • DeviceA가 hello 패킷을 전송하고(7월 22일 19:17:24), DeviceB가 이 패킷에 응답하고(7월 22일 19:17:25), DeviceA가 이 응답을 수신합니다(7월 22일 19:17:31).

    디바이스A

    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)

    장치B

    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)
    • DeviceA는 다른 hello 패킷을 전송하고(7월 22일 19시 17분 33초), DeviceB는 hello 패킷을 전송하고(7월 22일 19시 17분 34초) 2초 후에 피어에서 패킷을 수신합니다.

    디바이스A

    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

    장치B

    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)
    • DeviceA가 DeviceB에서 보낸 패킷을 수신하지 않는 기간 동안 프로토콜은 30초 후에 자신을 아래로 선언합니다.


    디바이스A

    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
    • DeviceB가 해당 피어에서 패킷을 수신하지 않습니다. 기본 보류 기간이 지나면 이 프로토콜은 자동으로 다운됩니다.


    장치B

    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

    캡처 분석:

    DeviceA는 DeviceB에서 패킷을 수신하지만 이 라우터가 피어에서 마지막으로 수신하는 패킷은 13분 17.31입니다. 그런 다음 DeviceA가 Hello 패킷을 전송합니다

    피어에서 아무런 응답 없이

    ISIS Random Flaps DeviceAISIS 임의 플랩 장치A

    DeviceB 캡처는 유사한 조건을 보여주며, 스위치는 피어에서 마지막 hello 패킷을 수신하지만, DeviceB는 응답 없이 hello 패킷을 전송하기 시작합니다.

    ISIS Unstable DeviceBISIS 불안정한 디바이스B

    내보낸 캡처에서는 Hello 패킷이 피어 간에 전달되지 않습니다. 이 문제는 운송과 관련이 있는 것으로 보입니다.

    개정 이력

    개정 게시 날짜 의견
    1.0
    27-Jul-2023
    최초 릴리스
    TAC Authored

    Cisco 엔지니어가 작성

    • Adriana Pacheco
      Cisco TAC 엔지니어

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