Strange DHCP issue

Got a problem with Viscosity or need help? Ask here!

matt.wasserman

Posts: 14
Joined: Sun May 22, 2011 9:41 pm

Post by matt.wasserman » Sat Jan 14, 2012 8:37 am
Not Viscosity specific, seems to be an OpenVPN issue.

When the DHCP lease on the local network gets renewed, the DNS server assigned by local DHCP gets wiped out, leaving only the DHCP server on VPN. So users can't resolve anything but VPN resources.

Anyone else seen anything like this? Anyone have any ideas? We are stumped.

Thanks
Matt

James

User avatar
Posts: 1973
Joined: Thu Sep 04, 2008 9:27 pm

Post by James » Tue Jan 17, 2012 1:59 am
Hi Matt,

Yes, a local network DHCP renew will cause the DNS settings to become overridden - Viscosity watches out for this and will instantly restore your VPN DNS server's if this occurs. However as your DNS servers are coming from the remote DHCP server, rather than using Viscosity's DNS support, then this restore process won't take place.

Switching to pushing out your DNS servers and domains from the OpenVPN server (with Viscosity's DNS support enabled) for the connection will solve the issue. However it would be nice to see if we can come up with a solution for your current setup as well - how have you implemented DHCP DNS support (using the scripts here)?

Cheers,
James
James Bekkema
Viscosity Developer

Web: http://www.sparklabs.com
Support: http://www.sparklabs.com/support
Twitter: http://twitter.com/sparklabs

matt.wasserman

Posts: 14
Joined: Sun May 22, 2011 9:41 pm

Post by matt.wasserman » Tue Jan 17, 2012 11:10 am
What I don't understand is why this only became an issue very recently. Since the first of the year.

But thanks for directing me toward that script - I'll take a look.

James

User avatar
Posts: 1973
Joined: Thu Sep 04, 2008 9:27 pm

Post by James » Fri Jan 20, 2012 1:01 pm
Hi Matt,

Are you using Viscosity's simultaneous DNS support setting, or are you using normal DNS support?

It has been quite some time since we have released any updates that change DNS behaviour (and we haven't released any Mac updates at all this year), so I'm unsure of what could have changed. Perhaps the problem could have always existed, but a shorter DHCP-lease time is making it more noticeable?

Cheers,
James
James Bekkema
Viscosity Developer

Web: http://www.sparklabs.com
Support: http://www.sparklabs.com/support
Twitter: http://twitter.com/sparklabs
4 posts Page 1 of 1