Good day all,
We have 7 Nexus 2000 dual-homed to 2 cisco nexus 5548UP using vPC in production, deployed as a routed access layer because the nexus 5000 have the layer 3 daughtercard and it does eigrp routing and also HSRP .
This weekend we did some tests for high availability, the first one was to take down the vpc peer-link and it behaved as stated in the documentation, the vpc secondary shut down the vpc members, we got the vpc peer-link and all good, no problems whatsoever. Second test was shutting down the vpc secondary nexus 5000 and we had no problems either, we powered on the nexus 5000 again and all good.
Problem was with our final test, we shut down the nexus 5000 configured as vpc primary, no problems there. Then we powered on the switch and the vpc adjacency formed ok, after the delay the vpcs went up and the FEX started to go online one by one, and just when i was thinking "what a wonderful technology", when the final FEX became online and something happened, the communication in all the DataCenter was intermittent, 6 to 10 pings got through and then 10 pings timed out and so on, and it happened to all the devices in the datacenter, I didn't have much time to do the troubleshooting because it affected all the datacenter but the show vpc results seemed OK and all the FEX appeared as Online so i don't really know what happened, I had to reload the vpc primary nexus 5000 and when it started back again it worked.
Have any of you encountered this problem? I thought the failure of a vpc peer (primary or secondary) would be seamless, or at least that's what cisco states.
both N5K have the same specs and NX-OS version:
BIOS: version 3.5.0
loader: version N/A
kickstart: version 5.0(3)N2(1)
system: version 5.0(3)N2(1)
power-seq: Module 1: version v1.0
Module 2: version v1.0
Module 3: version v5.0
uC: version v126.96.36.199
SFP uC: Module 1: v188.8.131.52
BIOS compile time: 02/03/2011
kickstart image file is: bootflash:/n5000-uk9-kickstart.5.0.3.N2.1.bin
kickstart compile time: 6/13/2011 6:00:00 [06/13/2011 07:43:33]
system image file is: bootflash:/n5000-uk184.108.40.206.N2.1.bin
system compile time: 6/13/2011 6:00:00 [06/13/2011 09:33:42]
cisco Nexus5548 Chassis ("O2 32X10GE/Modular Universal Platform Supervisor")
Intel(R) Xeon(R) CPU with 8299528 kB of memory.