14.14 AToM

Hello,

 

I wanted to play with the packet size when pinging from SW3 to SW4, if the size is above 1474 the ping is unsuccessful.

 

In the DocCD, i see in the MTU usage guidelines, so when using ethernet port we have to set the MTU size to 1526 (26 bytes exactly the difference i had when playing with my pings).

I put on R5, R6 ip mtu 1526 and on my switches : system mtu 1526 but get no results.

 

Any help is appreciated :).

 

http://www.cisco.com/en/US/docs/ios/mpls/configuration/guide/mp_any_transport_ps6441_TSD_Products_Configuration_Guide_Chapter.html#wp1157197

Comments

  • As per the blueprint , this is not part of the lab exam . Only MPLS L3 VPN is covered .

     

  • As per the blueprint: other related topics may also appear on any specific delivery of the exam...

    Anyway, I configured my routers and suddenly everything starts to flap:

    *Mar  3 13:48:31.152: %LDP-5-NBRCHG: LDP Neighbor 150.1.5.5:0 (2) is UP
    Rack1R6#
    *Mar  3 13:48:56.708: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Mar  3 13:49:22.128: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from FULL to DOWN, Neighbor Down: Dead timer expired
    Rack1R6#
    *Mar  3 13:49:33.308: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is UP
    Rack1R6#
    *Mar  3 13:49:34.456: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from LOADING to FULL, Loading Done
    Rack1R6#
    *Mar  3 13:50:06.008: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Mar  3 13:50:12.604: %LDP-5-NBRCHG: LDP Neighbor 150.1.5.5:0 (2) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Mar  3 13:50:29.620: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from FULL to DOWN, Neighbor Down: Dead timer expired
    Rack1R6#
    *Mar  3 13:50:42.060: %TCP-6-BADAUTH: No MD5 digest from 155.1.146.4(646) to 155.1.146.6(38077) (RST)
    Rack1R6#
    *Mar  3 13:50:44.124: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is UP
    Rack1R6#
    *Mar  3 13:50:47.216: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from LOADING to FULL, Loading Done
    Rack1R6#
    *Mar  3 13:51:18.504: %LDP-5-NBRCHG: LDP Neighbor 150.1.5.5:0 (2) is UP
    Rack1R6#
    *Mar  3 13:51:32.116: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Mar  3 13:51:55.240: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from FULL to DOWN, Neighbor Down: Dead timer expired
    Rack1R6#
    *Mar  3 13:52:12.248: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from LOADING to FULL, Loading Done
    Rack1R6#
    *Mar  3 13:52:12.400: %TCP-6-BADAUTH: No MD5 digest from 155.1.146.4(646) to 155.1.146.6(63194) (RST)
    Rack1R6#
    *Mar  3 13:52:14.444: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is UP
    Rack1R6#
    *Mar  3 13:52:36.228: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Mar  3 13:52:48.520: %LDP-5-NBRCHG: LDP Neighbor 150.1.5.5:0 (2) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Mar  3 13:53:01.512: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from FULL to DOWN, Neighbor Down: Dead timer expired
    Rack1R6#
    *Mar  3 13:53:17.496: %TCP-6-BADAUTH: No MD5 digest from 155.1.146.4(646) to 155.1.146.6(21284) (RST)
    Rack1R6#
    *Mar  3 13:53:19.564: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is UP
    *Mar  3 13:53:19.632: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from LOADING to FULL, Loading Done
    Rack1R6#
    *Mar  3 13:53:37.280: %LDP-5-NBRCHG: LDP Neighbor 150.1.5.5:0 (2) is UP
    Rack1R6#
    *Mar  3 13:53:49.652: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Mar  3 13:54:14.272: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is UP
    Rack1R6#
    *Mar  3 13:54:16.208: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from LOADING to FULL, Loading Done
    Rack1R6#
    *Mar  3 13:54:19.552: %BGP-5-ADJCHANGE: neighbor 150.1.4.4 Down Peer closed the session
    Rack1R6#
    *Mar  3 13:54:37.560: %BGP-5-ADJCHANGE: neighbor 150.1.4.4 Up
    Rack1R6#
    *Mar  3 13:54:59.492: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Mar  3 13:55:24.344: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from FULL to DOWN, Neighbor Down: Dead timer expired
    Rack1R6#
    *Mar  3 13:55:38.412: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is UP
    Rack1R6#
    *Mar  3 13:55:42.208: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from LOADING to FULL, Loading Done
    Rack1R6#
    *Mar  3 13:56:10.968: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Mar  3 13:56:14.948: %LDP-5-NBRCHG: LDP Neighbor 150.1.5.5:0 (2) is DOWN (Discovery Hello Hold Timer expired)

    Has anyone experienced a similar issue?

  • Mmmm... strange...

    Configured the interfaces on SW3 and SW4 and now all is stable.

    If someone has an explanation for this, please let me know.

    Cheers

  • I am getting similar issue.

    Rack1R6#
    *Nov  2 10:06:05.531: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from FULL to DOWN, Neighbor Down: Dead timer expired
    Rack1R6#
    *Nov  2 10:06:11.671: %BGP-5-ADJCHANGE: neighbor 150.1.4.4 Down BGP Notification sent
    Rack1R6#
    *Nov  2 10:06:11.671: %BGP-3-NOTIFICATION: sent to neighbor 150.1.4.4 4/0 (hold time expired) 0 bytes
    Rack1R6#
    *Nov  2 10:06:23.827: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from LOADING to FULL, Loading Done
    Rack1R6#
    *Nov  2 10:06:38.863: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is UP
    Rack1R6#
    *Nov  2 10:06:41.999: %BGP-5-ADJCHANGE: neighbor 150.1.4.4 Up
    Rack1R6#
    *Nov  2 10:07:13.215: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Nov  2 10:07:34.619: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from FULL to DOWN, Neighbor Down: Dead timer expired
    Rack1R6#
    *Nov  2 10:07:55.667: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from LOADING to FULL, Loading Done
    Rack1R6#
    *Nov  2 10:08:00.703: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is UP
    Rack1R6#
    *Nov  2 10:08:22.371: %LDP-5-NBRCHG: LDP Neighbor 150.1.5.5:0 (2) is DOWN (Discovery Hello Hold Timer expired)
    *Nov  2 10:08:22.835: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Nov  2 10:08:47.227: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from FULL to DOWN, Neighbor Down: Dead timer expired
    Rack1R6#
    *Nov  2 10:09:04.315: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from LOADING to FULL, Loading Done
    Rack1R6#
    *Nov  2 10:09:19.355: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is UP
    Rack1R6#
    *Nov  2 10:09:47.635: %LDP-5-NBRCHG: LDP Neighbor 150.1.5.5:0 (2) is UP
    Rack1R6#
    *Nov  2 10:09:58.971: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Nov  2 10:10:23.383: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from FULL to DOWN, Neighbor Down: Dead timer expired
    Rack1R6#
    *Nov  2 10:10:40.115: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from LOADING to FULL, Loading Done
    Rack1R6#
    *Nov  2 10:10:55.155: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is UP
    Rack1R6#
    *Nov  2 10:11:10.159: %LDP-5-NBRCHG: LDP Neighbor 150.1.4.4:0 (1) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Nov  2 10:11:17.639: %LDP-5-NBRCHG: LDP Neighbor 150.1.5.5:0 (2) is DOWN (Discovery Hello Hold Timer expired)
    Rack1R6#
    *Nov  2 10:11:35.259: %OSPF-5-ADJCHG: Process 1, Nbr 150.1.4.4 on FastEthernet0/0.146 from FULL to DOWN, Neighbor Down: Dead timer expired

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