IS-IS not forming Adjacency - stuck on ES-IS

[Amos Kafwembe]

Hey all,

got a strange one here. I am using ME 3600 and 3800 on a point to point fiber link. I have done my config as below, however, the IS-IS adjacency isn't forming. When i do a "show clns neighbor" i can see the neighbor but the protocol is stuck on ES-IS. Checking the logs i am getting the below error message; please advise. Most documentation is pointing to a mismatched MTU but i have checked and i don't have any mismatched MTU.

router isis as47888
 net 49.0001.aaaa.bbbb.ccfg.00
 is-type level-2-only
 ispf level-2 60
 metric-style wide
 fast-flood 10
 ignore-attached-bit
 set-overload-bit on-startup wait-for-bgp
 max-lsp-lifetime 65535
 lsp-refresh-interval 65000
 spf-interval 5 1 20
 prc-interval 5 1 20
 lsp-gen-interval 5 1 20
 no hello padding
 log-adjacency-changes
 metric 100000
 fast-reroute per-prefix level-2 all
 fast-reroute remote-lfa level-2 mpls-ldp
 passive-interface Loopback0
 bfd all-interfaces
!
!
interface GigabitEthernet0/11
 no switchport
 mtu 9000
 ip address 10.0.0.245 255.255.255.254
 ip router isis as47888
 bfd interval 50 min_rx 50 multiplier 3
 no bfd echo
 isis network point-to-point
 isis metric 2 level-2
 isis csnp-interval 10
end

####################

router isis as47888
 net 49.0001.aaaa.bbbb.ccde.00
 is-type level-2-only
 ispf level-2 60
 metric-style wide
 fast-flood 10
 ignore-attached-bit
 set-overload-bit on-startup wait-for-bgp
 max-lsp-lifetime 65535
 lsp-refresh-interval 65000
 spf-interval 5 1 20
 prc-interval 5 1 20
 lsp-gen-interval 5 1 20
 no hello padding
 log-adjacency-changes
 metric 100000
 fast-reroute per-prefix level-2 all
 fast-reroute remote-lfa level-2 mpls-ldp
 passive-interface Loopback0
 bfd all-interfaces
!
!
interface GigabitEthernet0/24
 no switchport
 mtu 9000
 ip address 10.0.0.244 255.255.255.254
 ip router isis as47888
 bfd interval 50 min_rx 50 multiplier 3
 no bfd echo
 isis network point-to-point
 isis metric 2 level-2
 isis csnp-interval 10
end

sh logg

056533: *Aug  4 20:04:05.080 CAT: ISIS-Adj: Sending serial IIH on GigabitEthernet0/24, 3way state:DOWN, length 8996
056534: *Aug  4 20:04:14.268 CAT: ISIS-Adj: Sending serial IIH on GigabitEthernet0/24, 3way state:DOWN, length 8996

#sh clns neighbors
Tag as47888:
System Id      Interface   SNPA                State  Holdtime  Type Protocol
2883.3004.1180 Gi0/24      362.882a.fdcf      Up     254       IS   ES-IS

[Amos Kafwembe]

Peter,

the issue has been resolved by adding this command under MPLS "mpls ldp igp sync holddown 600000" it had something to do with the LDP synchronising before the IGP. therefore, before ISIS could converge it would find that the LDP had already converged and therefore not proceed to form an adjacency.

[Peter Paluch]

Hi Amos,

I am glad you got it running - whatever workaround worked is probably good enough at this point. The solution you have implemented has basically told IS-IS to wait up to 600 seconds (why so long, though?) for LDP to signal that it has exchanged all labels and the IGP adjacency can go up.

However, why should this command - mpls ldp igp sync holddown - have an effect? Your IS-IS configuration does not contain the mpls ldp sync command and your interfaces do not have the mpls ip command configured, at least in the configurations you have posted. Have you been posting simplified, shortened configurations?

Best regards,
Peter

[Amos Kafwembe]

Hi Peter,

No, i haven't been posting shortened configs. The configs posted are full interface configs.

[Peter Paluch]

Hi Amos,

I am sorry to return to this thread so late.

Is there anything new in this issue? I am still not convinced about the solution although I am glad it is working for you.

Best regards,
Peter