Our datacenter is requiring that our 7510 controller be dual homed to two seperate Nexus 5k switches set up for vPC.There are eight HA pairs of 7510's with about 4k AP's on each WLC in FlexConnect mode . They have connected the primary WLC in the pair to one set of switches and its HA standby to two other switches in another rack in the datacenter. Prior to that, each WLC was connected to one switch over a port channel with LAG enabled.
So, now to the problem....when the switches were cabled in the new required way, only half of them were done. Some WLC pairs remained in the single switch/Port Channel configuration. Mobility pairs were configured between some of the WLC's and then things got a little crazy. AP's couldn't find their way back to the WLC HA pair that was configured as their primary controller (no secondary configured). The AP's started showing up on other controllers in the mobility group and lost some of the FlexConnect settings like VLAN mappings on the WLAN's. All of these AP's were in production and it starting taking down sites. Several thousand went down before we figured out what was going on.
To stop AP's from migrating, we broke the mobility between all of the controllers. Now none of them has a mobility peer. The WLC's are now one HA pair of 4k AP's each. The cable configuration is four controller pairs have split connections to two separate 5k running vPC with 7K's upstream that are also vPC. The second WLC in the pair is split between to switches with the same vPC configuration.
Of course the AP's stopped moving once we stopped the mobility between WLC's. Nevertheless, now we are unable to ping some of the WLC's from the Nexus 5K's to the management interface of some of the WLC's even though they are all in the same subnet. In a few cases, some CPI's lost communication to some WLC's as well. This is not good.
My contention is that we should have all of the WLC's in the single switch configuration up to the 5k's with LAG and Port Channel like we normally do to Catalyst switches. There is no need to and it appears to be counterproductive to split the connections of the primary WLC to one set of switches with vPC and the HA WLC to two other switches and vPC. I think there is adequate redundancy upstream and our additional failsafe is the WLC's are already in HA.
I know this is long but I have to have a good solution if the datacenter manager won't change the requirement for connecting to 5k and vPC. Bottomline, how would anyone design a HA pair of 7510's to Nexus 5k or even 2K FEX and use vPC?????
Regards,
