[j-nsp] Strange IS-IS errors

[Eric]

All,

I am mostly sharing this so other people seeing this error can save 
themselves the trouble trying to find the solution themselves...

I suddenly saw these messages appearing in my system log and router 
generally going haywire, including a PE-1GE card starting to spit random 
MAC addresses...

Aug 31 13:08:49  r1-yyy1 rpd[2645]: RPD_ISIS_ADJDOWN: IS-IS lost L2 
adjacency to r1-xxx1 on ge-1/2/0.0, reason: Address Mismatch
Aug 31 14:13:56  r1-yyy1 rpd[2645]: RPD_ISIS_LSPCKSUM: IS-IS L2 LSP 
checksum error, interface so-0/1/1.0, LSP id r1-xxx1.00-00, sequence 
0x45177, checksum 0x181, lifetime 630
Aug 31 14:13:56  r1-yyy1 rpd[2645]: RPD_ISIS_LSPCKSUM: IS-IS L2 LSP 
checksum error, interface so-0/1/1.0, LSP id r2-xxx1.00-00, sequence 
0x3707a, checksum 0x9c98, lifetime 416
Aug 31 14:13:57  r1-yyy1 rpd[2645]: RPD_ISIS_ADJDOWN: IS-IS lost L2 
adjacency to r1-zzz on so-0/1/0.0, reason: Bad Hello
Aug 31 14:13:57  r1-yyy1 rpd[2645]: RPD_ISIS_LSPCKSUM: IS-IS L2 LSP 
checksum error, interface so-0/1/1.0, LSP id r1-zzz1.00-02, sequence 
0xe95, checksum 0xe0a, lifetime 1198
Aug 31 14:13:57  r1-yyy1 rpd[2645]: RPD_ISIS_LSPCKSUM: IS-IS L2 LSP 
checksum error, interface ge-1/3/0.0, LSP id r1-zzz1.00-02, sequence 
0xe95, checksum 0xe0a, lifetime 1196
Aug 31 14:13:58  r1-yyy1 rpd[2645]: RPD_ISIS_LSPCKSUM: IS-IS L2 LSP 
checksum error, interface so-0/1/2.0, LSP id r1-zzz1.00-02, sequence 
0xe95, checksum 0xe0a, lifetime 1192
Aug 31 14:14:05  r1-yyy1 rpd[2645]: RPD_ISIS_ADJUP: IS-IS new L2 
adjacency to r1-zzz1 on so-0/1/0.0
Aug 31 13:08:49  r1-yyy1 rpd[2645]: RPD_ISIS_ADJDOWN: IS-IS lost L2 
adjacency to r1-xxx1 on ge-1/2/0.0, reason: Address Mismatch

A little birdie whispered to me that this is almost without failing a 
FEB/FPC issue... and so apparently it was, one FEB replacement later 
everything works again.

Just to share!

Cheers!
--
Eric Loos