Cisci AP 1850 CSRF token

[mheddy439]

Good Afternoon,

We just updated our 1850s to the 8.10.151.0 previously it was on version 8.7.106.0.

Everything seems to be working fine when we try to end a DHCP lease, we get the error: Invalid CSRF token presented. Request rejected

I have tried several different browsers, and different settings within the browsers and still cannot figure out why we are getting this error.

I am not 100% sure if this article has anything to do with it?

https://www.cisco.com/c/en/us/support/docs/csa/cisco-sa-20190417-wlc-csrf.html

Any help would be great.

Thank you.

[Rich R]

1. If updating why use 8.10.151.0?  As per https://www.cisco.com/c/en/us/support/docs/wireless/wireless-lan-controller-software/200046-tac-recommended-aireos.html#anc4 8.10.171.0 is currently recommended.

2. Where are you seeing that error?  How are you trying to "end a DHCP lease"?  In windows "ipconfig /release" at command prompt does that but would never give you that kind of error!  Why would you want to do that anyway?  Just make sure the DHCP lease time is appropriate to your requirements then the lease will expire automatically after the client leaves.  You wouldn't use a browser for that!

[mheddy439]

I went off the Cisco recommended which said the upgrade to the 8.10.151.0

I get the error when I am inside Mobility Express - DHCP Server - DHCP Lease and then clicks the X to try to end the lease early.

We do it this way when we are testing certain things and just want to kick something off early, especially when we have IP Conflicts or trying to figure out a networking issue.

[Rich R]

Right! It's helpful to provide full detailed info on this from the start. So the bits we were missing:

- Mobility Express

- Internal DHCP server - note that this is only officially supported for site survey use which means it won't be tested for regular client use

- Using the ME GUI to try to clear the DHCP lease

I'd suggest updating to 8.10.171.0 - I think they've just forgotten to update the recommended release.  Generally ME should follow the same recommendations as the AireOS WLCs.

If that still has the same problem try different browsers and different versions of browsers.

If that doesn't help try CLI (console/SSH) - this is a web GUI problem so the CLI should still work fine.

If you wanted more help with the GUI you'd need to contact TAC but I'd expect them to tell you the internal DHCP is not supported apart from for AP on a stick site survey.  And realistically I don't think it would get fixed as it's approaching end of life (End of SW Maintenance 1 May 2023)