IS-IS Routers not establishing adjacency

Discussion in 'Cisco' started by alex_edwards2000, Mar 27, 2006.

  1. Hi,

    I am working through an IS-IS configuration in the SYBEX BSCI book. I
    followed the example configs exactly but my routers can not establish
    adjacency. Any IS-IS gurus with any ideas?

    I don't want to post configs yet as the config from the sample chapter
    is very straightforward. I'm probably missing a trick.

    Thanks
     
    alex_edwards2000, Mar 27, 2006
    #1
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  2. alex_edwards2000

    chris Guest

    You're not giving any information to go on. How are we supposed to know what
    you have configured?
     
    chris, Mar 27, 2006
    #2
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  3. alex_edwards2000

    Charlie Root Guest

    MTU mismatch comes first to my mind.I don't know what is in BSCI book, so
    without seeing what have you configured there are many guesses. Did you
    configure clns routing? did you configure 'clns routing', is-is routing
    process with NET, and 'ip router isis' on the interfaces?

    'debug isis adj' should give you some idea what might be wrong

    Kind regards,
    iLya
     
    Charlie Root, Mar 27, 2006
    #3
  4. I thought it may be a problem with MTU sizes but the mtu size used by
    RouterA and RouterB are the same.

    OK, here is the scenario and config:

    Two routers - RouterA and RouterB connected across a serial interface.

    Config for Router A - level 1
    ----------------------------
    RouterA#show run
    Building configuration...

    Current configuration : 640 bytes
    !
    version 12.2
    service timestamps debug uptime
    service timestamps log uptime
    no service password-encryption
    !
    hostname RouterA
    !
    !
    ip subnet-zero
    !
    clns routing
    !
    !
    !
    interface Ethernet0
    ip address 192.168.50.1 255.255.255.0
    ip router isis
    clns router isis
    no shutdown
    !
    interface Ethernet1
    no ip address
    shutdown
    !
    interface Serial0
    no ip address
    !
    interface Serial0.1
    ip address 192.168.40.1 255.255.255.0
    ip router isis
    clns router isis
    !
    interface Serial1
    no ip address
    !
    router isis
    net 01.0000.0000.0001.00
    is-type level-1
    !
    ip classless
    no ip http server
    !
    !
    !
    line con 0
    exec-timeout 0 0
    line aux 0
    line vty 0 4
    login
    !
    end

    Config for RouterB - level-1-2
    --------------------------
    RouterB#show run
    Building configuration...

    Current configuration : 1043 bytes
    !
    version 12.2
    service timestamps debug uptime
    service timestamps log uptime
    no service password-encryption
    !
    hostname RouterB
    !
    !
    ip subnet-zero
    !
    clns routing
    !
    !
    !
    interface Serial0
    no ip address
    shutdown
    !
    interface Serial1
    no ip address
    clockrate 64000
    !
    interface Serial1.1
    ip address 192.168.30.1 255.255.255.0
    ip router isis
    !
    interface Serial2
    no ip address
    clockrate 64000
    !
    interface Serial2.1
    ip address 192.168.40.2 255.255.255.0
    ip router isis
    clns router isis
    !
    router isis
    net 01.0000.0000.0002.00
    !
    ip classless
    no ip http server
    !
    !
    !
    line con 0
    line aux 0
    line vty 0 4
    login
    !
    end

    On RouterA, here is the output of show clns neighbor and debug isis
    adj:
    RouterA#show clns neighbor

    RouterA#
    01:29:09: ISIS-Adj: Sending L1 LAN IIH on Ethernet0, length 1497
    01:29:16: ISIS-Adj: Sending serial IIH on Serial0.1, length 1499
    01:29:18: ISIS-Adj: Sending L1 LAN IIH on Ethernet0, length 1497
    01:29:25: ISIS-Adj: Sending serial IIH on Serial0.1, length 1499
    01:29:25: ISIS-Adj: Sending L1 LAN IIH on Ethernet0, length 1497
    01:29:33: ISIS-Adj: Sending serial IIH on Serial0.1, length 1499
    01:29:35: ISIS-Adj: Sending L1 LAN IIH on Ethernet0, length 1497
    01:29:41: ISIS-Adj: Sending serial IIH on Serial0.1, length 1499show
    clns neighb
    or
    01:29:43: ISIS-Adj: Sending L1 LAN IIH on Ethernet0, length 1497

    RouterA#
    RouterA#
    RouterA#
    RouterA#show clns int e
    01:29:51: ISIS-Adj: Sending serial IIH on Serial0.1, length 1499 0
    Ethernet0 is up, line protocol is up
    Checksums enabled, MTU 1497, Encapsulation SAP
    ERPDUs enabled, min. interval 10 msec.
    RDPDUs enabled, min. interval 100 msec., Addr Mask enabled
    Congestion Experienced bit set at 4 packets
    CLNS fast switching enabled
    CLNS SSE switching disabled
    DEC compatibility mode OFF for this interface
    Next ESH/ISH in 0 seconds
    Routing Protocol: IS-IS
    Circuit Type: level-1-2
    Interface number 0x0, local circuit ID 0x1
    Level-1 Metric: 10, Priority: 64, Circuit ID: RouterA.01
    Number of active level-1 adjacencies: 0
    Next IS-IS LAN Level-1 Hello in 7 seconds
    RouterA#

    Some debug on RouterB:
    01:36:46: ISIS-Adj: Sending serial IIH on Serial2.1, length 1499ug isis
    a
    01:36:49: ISIS-Adj: Sending serial IIH on Serial1.1, length 1499dj
    IS-IS Adjacency related packets debugging is off
    RouterB#
    RouterB#show clns int s2.1
    Serial2.1 is up, line protocol is up
    Checksums enabled, MTU 1500, Encapsulation HDLC
    ERPDUs enabled, min. interval 10 msec.
    RDPDUs enabled, min. interval 100 msec., Addr Mask enabled
    Congestion Experienced bit set at 4 packets
    CLNS fast switching enabled
    CLNS SSE switching disabled
    DEC compatibility mode OFF for this interface
    Next ESH/ISH in 16 seconds
    Routing Protocol: IS-IS
    Circuit Type: level-1-2
    Interface number 0x0, local circuit ID 0x100
    Level-1 Metric: 10, Priority: 64, Circuit ID: RouterB.00
    Number of active level-1 adjacencies: 0
    Level-2 Metric: 10, Priority: 64, Circuit ID: RouterB.00
    Number of active level-2 adjacencies: 0
    Next IS-IS Hello in 2 seconds
     
    alex_edwards2000, Mar 27, 2006
    #4
  5. alex_edwards2000

    Charlie Root Guest

    That won't work with sub-interfaces when main serial interface uses HDLC -
    the router doesn't know where to deliver packets once they reach the
    router's main interface. Configure IP directly on the main interface.

    Kind regards,
    iLya
     
    Charlie Root, Mar 27, 2006
    #5
  6. This worked. The example in the book was configured for FRAME-RELAY.

    Many Thanks
     
    alex_edwards2000, Mar 28, 2006
    #6
  7. alex_edwards2000

    Charlie Root Guest

    with Frame-relay sub-interfaces surely will work because there is DLCI to
    distinguish between sub-interfaces.

    Kind regards,
    iLya
     
    Charlie Root, Mar 28, 2006
    #7
  8. alex_edwards2000

    ciscodagama Guest

    When using IS-IS with frame relay, you will also have to add a frame
    relay map for the CLNS protocol for IS-IS to work.

    Cisco da Gama
    http://ciscostudy.blogspot.com
     
    ciscodagama, Mar 29, 2006
    #8
  9. alex_edwards2000

    Xangadib Guest

    Have you solved it yet?

    Xangadib

     
    Xangadib, Apr 12, 2006
    #9
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