This got me yesterday! I configured an interface on my asr9000 with an incorrect mask..the mask overlapped (encompassed) another pre-existing interface . I guess IOS XR doesn't give you the warning like old IOS about overlapping networks.look what it did! .it forced down the other pre-existing interface. Then while I was unable to figure out my typo with the incorrect mask and had not yet look into the logs, but I just knew I had a bad problem with this core 9k, I simply rolled back config and it fix the backbone link. then later I found this in the logs. Thought I'd share with y'all.
RP/0/RSP0/CPU0:Aug 13 16:26:56.586 : ipv4_arm[268]: %IP-IP_ARM-3-CFLCT_FORCED_DOWN : The IPv4 address 10.101.1.10/30 on Bundle-Ether2 conflicts with other IPv4 addresses and has been forced down (this is after I did a config rollback) RP/0/RSP0/CPU0:Aug 13 16:46:00.738 : ipv4_arm[268]: %IP-IP_ARM-6-CFLCT_NO_LONGER : The IPv4 address 10.101.1.10/30 on Bundle-Ether2 is no longer forced down due to IPv4 address conflicts Aaron _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/