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ISIS Neighbprship flapping and error msg

Hello ,

i have faced problem with ISIS operation which after isis neoghbor ship  came up and i check Neighbor status " sh isis neigh " , " sh clns neigh "  and checked " sh isis database " then " sh ip route isis " , log on the  P router appear as following :

*Oct 13 14:26:25.527: %CLNS-4-LSPCKSUM: ISIS: Bad L2 LSP  0001.0000.0009.00-00 checksum E46D received on FastEthernet1/1, length  83, should be B244, bad count 3

R3-P-router#

*Oct 13 14:26:46.495: %CLNS-3-BADPACKET: ISIS: L2 CSNP, packet length 0  less than header length 33 from ca09.1ae0.001c (FastEthernet1/0)

R3-P-router#

*Oct 13 14:27:54.547: %CLNS-3-BADPACKET: ISIS: LAN L2 hello, bad circuit type 0 from ca09.1ae0.001c (FastEthernet1/0)

R3-P-router#

*Oct 13 14:29:03.263: %CLNS-3-BADPACKET: ISIS: LAN L2 hello, bad circuit type 0 from ca09.1ae0.001c (FastEthernet1/0)

R3-P-router#

*Oct 13 14:30:07.443: %CLNS-3-BADPACKET: ISIS: LAN L2 hello, bad circuit type 0 from ca09.1ae0.001c (FastEthernet1/0)

R3-P-router#

*Oct 13 14:31:08.383: %CLNS-3-BADPACKET: ISIS: LAN L2 hello, bad circuit type 0 from ca0a.1ae0.001c (FastEthernet1/1)

R3-P-router#

*Oct 13 14:32:17.955: %CLNS-3-BADPACKET: ISIS: LAN L2 hello, bad circuit type 0 from ca0a.1ae0.001c (FastEthernet1/1)

and led to BGP flapping between Edges also LDP flapping .

also i performed below commands to get more details :

R3-P-router#sh isis spf-log

    TID 0 level 1 SPF log

   When   Duration  Nodes  Count    First trigger LSP   Triggers

01:28:03        0       1       1                            PERIODIC

01:26:46        4       1       1    R3-P-router.00-00  TLVCONTENT

01:13:12        0       1       1                            PERIODIC

00:58:12        0       1       1                            PERIODIC

00:43:12        0       1       1                            PERIODIC

00:28:12        0       1       1                            PERIODIC

00:13:12        0       1       1                            PERIODIC

    TID 0 level 2 SPF log

   When   Duration  Nodes  Count    First trigger LSP   Triggers

00:14:20       12       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:14:00        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:13:12       12       7       1                            PERIODIC

00:12:55        4       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:11:57        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:10:48       12       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:10:37        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:09:38        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:09:28        4       7       1                            NEWADJ

00:08:23       12       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:07:18        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:06:08        4       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:05:00        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:02:39        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:01:41        4       7       1 0000.0000.0000.00-00  LSPEXPIRED

00:01:32        8       5       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:01:22        4       7       2    R3-P-router.00-00  NEWADJ TLVCONTENT

00:00:25        0       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:00:15        4       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

and

R3-P-router# sh isis spf-log

    TID 0 level 1 SPF log

   When   Duration  Nodes  Count    First trigger LSP   Triggers

01:29:13        0       1       1                            PERIODIC

01:27:56        4       1       1    R3-P-router.00-00  TLVCONTENT

01:14:22        0       1       1                            PERIODIC

00:59:22        0       1       1                            PERIODIC

00:44:22        0       1       1                            PERIODIC

00:29:22        0       1       1                            PERIODIC

00:14:22        0       1       1                            PERIODIC

    TID 0 level 2 SPF log

   When   Duration  Nodes  Count    First trigger LSP   Triggers

00:14:05        4       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:13:07        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:11:58       12       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:11:46        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:10:47        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:10:37        4       7       1                            NEWADJ

00:09:33       12       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:08:27        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:07:17        4       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:06:10        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:03:49        8       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:02:50        4       7       1 0000.0000.0000.00-00  LSPEXPIRED

00:02:41        8       5       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:02:31        4       7       2    R3-P-router.00-00  NEWADJ TLVCONTENT

00:01:34        0       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:01:24        4       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:00:43        4       7       1 0000.0000.0000.00-00  LSPEXPIRED

00:00:27        4       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

00:00:17       12       7       3    R3-P-router.00-00  NEWADJ TLVCONTENT

Topology as : [R8-PE1]-----[R3-P]---[R10-PE2]

                                          I

                                              I

                                   [R-9PE2]

only this logs for R8 neighborship  and R9,R10 happens sometimes !!!

Configuration on all routers very simple .

router isis 1

net 49.0001.0000.000X.00    ==> X = Router number

is-typ level-2-only

passive-interface lo0

and under connected interfaces [ ip  router isis 1 ]

N.B : i used 4 VXR 7606 , IOS 12.2[33] SRE9

if any one can support and help ,

thanks in advance

Mohamed

6 Replies 6

Peter Paluch
Cisco Employee
Cisco Employee

Hi Mohamed,

It seems as if there were corrupted IS-IS packets being originated in your network, or they got damaged during delivery.

Can you isolate the router with the SystemID of 0001.0000.0009? Is it the PE9? Also, which devices have the MAC addresses ca09.1ae0.001c and ca0a.1ae0.001c? I find it curious that you happen to have two devices with their MAC addresses differing in a single octet of their OUI but otherwise identical.

Can you verify using show interfaces and show ip traffic if there are any errors recorded for received frames and IP packets? I am trying to find out if there is a general problem in your network that causes frames/packets being corrupted in transit.

Have you just recently observed this phenomenon, or was it present all the time you are running IS-IS? If this is a sudden incident, were there any changes performed to the network, either to the physical installation or to the configuration, that preceded the occurence of this problem?

Best regards,

Peter

thank you peter for your reply , i know it's too late but i tried the same lab using another version of GNS3 and i didn't face this problem , may be this problem related to the simulator it self no networking issue .

Thank you again and have a nice day

Hi Mohamed,

Thank you for letting us know. Take care!

Best regards,

Peter

Peter

Just wanted to check you got my reply and that you didn't think i was being ignorant asnd ignoring you ?

Jon

Jon,

Please do not worry at all - everything is all right. I got your answer and I was very, very pleased to read it. I did not have time to respond, these are some hard days for me but please rest assured that I received your response, read it with the utmost pleasure, and that I have absolutely no bad feelings or thoughts whatsoever.

It is so good to see you being back, my friend...

Best regards,

Peter

Peter

Thanks, i just wasn't sure my PMs were getting through. Just for your info i don't have your e-mail (sorry i went a bit mad when i cleared up my inbox).  But feel free to drop me a line anytime and no rush if you are pressed for time.

Jon

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