WiFi good, but packet loss when pinging certain WLC interface

[Andrew White]

Hello,

Strange one here.  Firstly I'm no expert on our WLC 5508 (2 in HA mode).

We have a few interfaces under Controller > Interfaces I guess these are the VLANs for the SSIDs.

Our main SSID is on VLAN 121 and all is ok.  However if I ping the IP of the WLC interface for this VLAN there is about 50% packet loss.  The WLC connects to 2 Nexus core switches (port channel) and If I go onto both and ping this interface they have about 70% packet loss.

Form the WLC CLI the ping is 100% to itself (you never know).

Again no issues.  Other less busy interfaces are all good and 100% ping success.

Not sure if the interface is using QoS to put pings down the to the bottom of the queue and drop, not sure how I would find this out?

Thanks

[Flavio Miranda]

Hi

 You´re saying that your WLC is connected to Nexus via trunk and when you ping from Nexus to WLC you face packet loss?  I´d start revising the cabling/fiber  and GBIC  between booth. This can be a physical problem.

Check on Nexus interfaces is there are any drop, CRC etc. 

-If I helped you somehow, please, rate it as useful.-

[Andrew White]

Well I can see any errors/CRCs on any ports from the 2 x Nexus to the WLC. Strange the both have the issue. What is strange other VLANs that traverse the same cables from the Nexus’s to the WLC are all fine.

[Flavio Miranda]

If different vlans are fine, it must not be physical. 

  I´d check the config just to make sure but I agree that this make no sense.

-If I helped you somehow, please, rate it as useful.-

[Leo Laohoo]

What firmware is the WLC running on?

[Andrew White]

It's on 8.2.166 and we have 27 APs in FlexConnect mode.

We plan to go to 8.5.x soon.

I am pining today where no one is really using it and pings are fine.

Maybe bandwidth?  How can I check this though?

Can I upgrade straight to 8.5.x.x from 8.2.x.x?

Thanks

[patoberli]

Make sure you have all the needed VLANs allowed in the Trunk / VPC.
The WLC has LAG mode enabled?
Have you made sure that the active WLC is using one VPC and the standby WLC is using another VPC?

[Andrew White]

Hello,

Fixed! Well it will be soon. I put this IP in our monitoring system as noticed all weekend it was fine, but when users started to turn up I started to get packet loss.  I then thought is it another device and it turns out a laptop has been statically configured with the same IP (oh my).  

Anyway I'm now interested how I can check if I'm using LAF ports on the WLC, how do I check?  The Nexus swtiches already do and have the correct VLANs allowed across.

Thanks

[patoberli]

It's under Controller - General. Please note, this is normally configured correct and only rarely needs to be changed. The switch interfaces also must be correctly configured for this. Lastly, some WLC models don't allow this to be changed anyway.

[Andrew White]

Thanks, just says LAG mode enabled.

The Nexus ports are Port Channels leading to the WLC

[patoberli]

Ok, that sounds correct.