Debugging VPN problems

This page is about debugging VPN problems. For more general VPN notes, see the dedicated VPN page.

The VPN is supplied and maintained by Campus IT, so if the suggestions below don't fix things, you might need to contact the helpdesk for more assistance. Although we at phas-it@glasgow.ac.uk can't fix many VPN problems, we'd like to be aware of widespread issues here, so consider letting us know about the problem too.

In late 2021, there seemed to be some intermittent problems with VPN connections, affecting online physics and astronomy labs. Being intermittent (the worst sort of problem) it's been hard to pin down the cause or even the real nature of the problem. To help the helpdesk (and us) narrow this down, when reporting VPN problems please look at the following checklist:

• Are you using the most recent version of the client?

• Web proxy settings: if used, ensure this is set to automatic only, and not configured manually (see instructions – few users these days need to use this).

• Confirm you're not connected to two VPNs simultaneously (this sort of configuration can be made to work, but it's a significant complication).

• Confirm that, when you connect, you're using the Off_Campus_Use group.

• Clear your browser cache and try again (some instructions – this is unlikely to really fix things, but it can rule out some weirdness in some circumstances, and generally does no harm).

• Try using the alternative profile GUSecure2 (if this isn't visible in your VPN client, then type in gucsasa3.cent.gla.ac.uk).

• Report anomalous behaviour:

  • The university has plenty of VPN hardware capacity, but there are various other potential choke-points, on-campus and off, so if user problems seem to be associated with high network traffic, that would be interesting to report.
  • Similarly, there are reports of VPN connections spontaneously disconnecting and reconnecting. If you're observing that, do mention it.

• As with any problem of this sort, always include the version of the client and the OS, and any error messages that have appeared (VPN errors unfortunately tend to be just ‘it doesn't work’ rather than throwing up lots of errors, but any text in a dialogue box, for example, might help someone get some insight).

• If you're on macOS or Linux and are feeling bold, it would probably be helpful, in the context of VPN problems, to open a terminal and cut-and-paste the output of the commands netstat -rn and traceroute brutha0.physics.gla.ac.uk into any problem report.

Further random thoughts:

• Does the error message provide any useful suggestion as to the cause of the issue? If the cause is not obvious, check for others mentioning this error on your preferred search engine.

• [Windows:] In some cases, completely closing the Cisco AnyConnect client (right click on Cisco icon in the taskbar and select 'Quit') and re-opening again has been known to resolve a number of issues. Specifically, this resolves an issue where local (any non-Campus) traffic fails to resolve.

• Are you able to load any other services that are only available on the Campus network? A current list to try is:

  • P&A remote desktop service
  • ‘Research impact’ site

• Although we prefer to have a reason as to why issues arise, as always, saving any open work and rebooting the affected device can sometimes make problems go away, if you're in a hurry (fingers crossed!).

• Remove any stored passwords from the Cisco client and authenticate again. If credentials are stored and your password has been changed, this will result in errors.

• Check for updates to your operating system and that you are running the latest version of the client suggested by IT Services.

  In some cases, it seems that uninstalling the current client version, prior to installing a new version, ensures that the correct VPN profiles are installed.

P&A IT documentation — directory – Last modified by Norman Gray on 2022 February 16