Our VPN tunnel gets disconnected every 70 minutes
Posted on 2008-06-19
For the past four years, we have had a successful VPN tunnel that goes coast to coast via a Sonic Wall and Cisco Pix (model ???). We're looking for assistance with a problem that crept up last week after Comcast installed a new modem (do not know the old or new model #). Shortly after the new modem was installed, we would get VPN drops every 20mins - 1 hour but never the internet.
Comcast has adjusted all settings on the new modem to the exact of the old modem (as far as I'm told). After one week of this problem, we decided to purchase a Watchguard X20e-W (for more reasons than this VPN drop). Hoping that the problem would magically disappear, we installed it with the same VPN configurations as best as we knew (matching those of the remote Cisco Pix device).
Now, we can set our watch to when the VPN tunnel goes down. Every 70minutes, we'll get a VPN brown out. If we click the "regenerate IPSec key" the VPN comes right back. (eg. If we get a brown out at 9:00am but do not regenerate until 9:12am, we'll still get another brown out at 10:10am). Based on the example, I'm thinking the problem exists outside of our network but do not know where to look.
Where is the problem? Comcast network - blocking critical heartbeat traffic? Remote VPN end point?