here are few posts (quite some time ago) telling the same trouble:

The VPN Client does *NOT* restore the original DNS settings.

Upon BM3.8.2 Massimo told, that this is a bug in that version of the VPN
client. I face this issue with 3.8.16 and nwclient 4.91.4 with or without
the three currently available hotfixes [1]

Anybody else facing this trouble with the current VPN client release?
May be an older one works better, any experiences?

This trouble is fact even after clean disconnects. But it happens only now and then,
I might need to try it 50 times to see it once.

a followup in CMD boxes with ipconfig /all does show, that the times
to restore the original DNS settings vary from 2 to 30 seconds. Mostly about 5 seconds.

Massimo also told, that a "VPN-down" due to a Win-Shutdown can cause this: So is
there a possibility to trigger a "clean-VPN down" in the Win-shutdown sequence?

As a workaround I packed this line into all users "run" key:

netsh int ip set dns name="LAN-Verbindung" source=dhcp

so at least after a reboot it's corrected.

Any suggestions appreciated,

Novell Client 4.91 Post-SP2/3/4 NWSPOOL.DLL
Novell Client post-4.91 SP4 LGNCXW32.DLL
Novell Client 4.91 Post-SP4 NWGINA.DLL 1

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