Windows 10 / F5 VPN Client: Sometimes when my VPN client connection dies, I lose all remote network connectivity – WHY?

  adapter, networking, ping, vpn, windows

I have been having this issue for quite some time. It is intermittent and doesn’t happen too often, but when my VPN dies, it usually takes down all remote connectivity with it. Local LAN connectivity is fine – I can reach all local hosts. But when I try doing a traceroute to a remote IP, e.g. 8.8.8.8, it fails. If I try to PING a remote IP address, this is the bizaar output I get:

enter image description here

No one has been able to provide anything close to a satisfactory answer. The best I got was "uninstall all the WAN Miniport Adapters then reboot." Um…no! Damnit! Why should I have to even reboot, let alone uninstall Adapters?

"Microsoft, sort your stupid network stack out!" … at least, that is how I felt, until tonight (although that feeling will never fully dissipate…).

This has had me positively stumped for months. I’ve tried Wiresharking, Process Monitoring, but nothing of any meaning shows up.

Tonight, however, I discovered a smoking gun:

enter image description here

Even better, I found a workaround (though on this machine it requires elevation):

route delete 0.0.0.0
route add 0.0.0.0 mask 0.0.0.0 192.168.1.1 metric 1
route delete 224.0.0.0
route add 224.0.0.0 mask 240.0.0.0 192.168.1.1 metric 1

Multicast routes I’m not so concerned about, but for the sake of completeness I also did that since it was obvious to me that whatever jacked up the default route metric also jacked up the Multicast route metric.

So this got my remote connectivity working again. Good.

BUT, this still leaves me with these questions:

  1. What could cause the ROUTE METRIC to be set so high like that? My gut tells me the F5 VPN client, but is feels like a bug to me.
  2. Does anyone know if the F5 VPN client has a client policy setting that changes the ROUTE METRIC of the default route?
  3. What on earth does the Windows error message "No resources" actually refer to? What "resource" do I have no more of?
  4. Where does this message come from? I.e. What process, executable or DLL generates this output or has this message complied into it?

I am glad I now have a workaround and I hope it helps others with the same issue, but if anyone can enlighten me as to the answers of any of the above questions I’d like to hear from you.

Source: Windows Questions

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