ISIS BAD_PDU_FORMAT

[ElshanMammadli5597]

We faced issue related to ISIS. Two N540 connect each other over bundle interface.

so we saw that  isis is up but ping is unstable. ping's success percent is 30% and appears some logs related to  isis bad lsp. we  some logs is below

RP/0/RP0/CPU0:Sep 11 05:54:09.153 +04: isis[1005]: %ROUTING-ISIS-4-ERR_BAD_PDU_FORMAT : ISIS (aztelekom): P2P IIH received from Bundle-Ether11 SNPA d46a.35e6.e4db contains a format error: Item at offset 0 within Area Addresses TLV at packet offset 7252 overflows end of TLV (length 256; space available

RP/0/RP0/CPU0:Sep 11 05:54:44.325 +04: isis[1005]: %ROUTING-ISIS-4-LSPCKSUM : ISIS (aztelekom): Bad L2 LSP 0020.0019.0001.00-00 checksum a367 received on Bundle-Ether36, length 1413, should be 9670, bad count 9060

RP/0/RP0/CPU0:Sep 11 05:55:10.446 +04: isis[1005]: %ROUTING-ISIS-4-ERR_BAD_PDU_FORMAT : ISIS (aztelekom): P2P IIH received from Bundle-Ether11 SNPA d46a.35e6.e4db contains a format error: Item at offset 0 within Area Addresses TLV at packet offset 7252 overflows end of TLV (length 256; space available

RP/0/RP0/CPU0:Sep 11 05:55:44.328 +04: isis[1005]: %ROUTING-ISIS-4-LSPCKSUM : ISIS (aztelekom): Bad L2 LSP 0020.0019.0001.00-00 checksum a367 received on Bundle-Ether36, length 1413, should be ac5e, bad count 9551

RP/0/RP0/CPU0:Sep 11 05:56:44.331 +04: isis[1005]: %ROUTING-ISIS-4-LSPCKSUM : ISIS (aztelekom): Bad L2 LSP 0020.0019.0001.00-00 checksum a367 received on Bundle-Ether36, length 1413, should be 9670, bad count 10164 RP/0/RP0/CPU0:

Sep 11 05:56:47.171 +04: isis[1005]: %ROUTING-ISIS-4-ERR_BAD_PDU_FORMAT : ISIS (aztelekom): P2P IIH received from Bundle-Ether36 SNPA 00bc.6045.30dd contains a format error: Item at offset 0 within Area Addresses TLV at packet offset 7252 overflows end of TLV (length 256; space available

RP/0/RP0/CPU0:Sep 11 05:57:44.334 +04: isis[1005]: %ROUTING-ISIS-4-LSPCKSUM : ISIS (aztelekom): Bad L2 LSP 0020.0019.0001.00-00 checksum a367 received on Bundle-Ether36, length 1413, should be ac5e, bad count 10842

RP/0/RP0/CPU0:Sep 11 05:58:14.541 +04: isis[1005]: %ROUTING-ISIS-4-ERR_BAD_PDU_FORMAT : ISIS (aztelekom): P2P IIH received from Bundle-Ether36 SNPA 00bc.6045.30dd contains a format error: Item at offset 0 within Area Addresses TLV at packet offset 7252 overflows end of TLV (length 256; space available

RP/0/RP0/CPU0:Sep 11 05:58:44.337 +04: isis[1005]: %ROUTING-ISIS-4-LSPCKSUM : ISIS (aztelekom): Bad L2 LSP 0020.0019.0001.00-00 checksum a367 received on Bundle-Ether36, length 1413, should be 9670, bad count 11528 RP/0/RP0/CPU0:

Sep 11 05:59:15.176 +04: isis[1005]: %ROUTING-ISIS-4-ERR_BAD_PDU_FORMAT : ISIS (aztelekom): P2P IIH received from Bundle-Ether11 SNPA d46a.35e6.e4db contains a format error: Item at offset 0 within Area Addresses TLV at packet offset 7252 overflows end of TLV (length 256; space available

[M02@rt37]

Hello @ElshanMammadli5597 

As concerned the log message "%ROUTING-ISIS-4-ERR_BAD_PDU_FORMAT"

https://quickview.cloudapps.cisco.com/quickview/bug/CSCef66715

Workaround: Ensure the NET router id's are of the same length

[ElshanMammadli5597]

We have to swap existing router to new router. Routers are in same familiy(Cisco N540). Everything on old box works well but when we do copy+paste to new router issue appears. I verify all config all are same

[Giuseppe Larosa]

Hello @ElshanMammadli5597 ,

>> I verify all config all are same

>> Everything on old box works well but when we do copy+paste to new router issue appears.

the new router needs to use a different NET or they will have the same system ID .

You cannot test the new device versus the old one without some changes.

Edit:

check the errors on bundle interface member links

>> so we saw that isis is up but ping is unstable. ping's success percent is 30% and appears some logs related to isis bad lsp. we some logs is below

if you get only 30% of success for ping the error messages can be the sign of errors in received ISIS PDUs, for example  LSP complains of a bad checksum or a not correct packet length .

so use show interface type x/y/z/k to check input errors.

then you may  want to check transceivers for rx/tx power levels if the links are fiber based.

note if they are single mode fiber optics they may be too strong for back to back connection.

Hope to help

Giuseppe

[ElshanMammadli5597]

we copy config one to one. NET was correct. i  have verified several time.  also we have clear al config and configure it as new router with new parametrs, new ip addressed . but result is same

[ElshanMammadli5597]

When we configure ospf we saw same issue with ospf.  some log appear  related to ospf bad cheksum.

[M02@rt37]

 @ElshanMammadli5597 

Which IOS-XR version, please ?

[ElshanMammadli5597]

IOS-XR version is 7.11.2

[ElshanMammadli5597]

This is related my case. I have opened case about this issue. the comment Under title "Related Community Discussions" is my comments

[ElshanMammadli5597 · Accepted solution]

It was hardware issue. We changed hardware with same configuration and the issue solved

[M02@rt37]

Thank's for your feedback @ElshanMammadli5597