I've got a peculiar problem that I'm hoping someone can help me resolve.
We have a voip phone system that consists of a Cisco/Linksys SPA9000 PBX and several SPA942 phones. This equipment is spread across 2 offices so we have just deployed RV042s at both sites with a gateway-gateway VPN tunnel connecting the sites. This works fine; the phones can make calls in/out like any normal PBX system should.
Now here's the issue. I am at a remote site and I need to log into the web administration pages of the SPA devices to make some changes. I have set up QuickVPN on my computer and can successfully log in to the network of either office. I can load up the web administration pages of any of the SPA devices. However, whenever I press "Submit all changes" to save the changes on the device, my changes are NOT saved. The web page will revert back to the same values as if I hadn't made any changes.
Now in the past when this SPA equipment was located at one site, we port-forwarded a port on that router so that we could get to the web administration page of each device. I had no problem making and saving changes to any SPA equipment.
So the only thing that has changed now is that I am accessing the web administration page via a client VPN tunnel. Can anyone shed some light about what is going on here?
BTW, an interesting observation is that via the QuickVPN tunnel, if I make a change on the RV042's web administration page, it WILL get saved properly.
I was wondering if this was because of an MTU issue so I tried changing the RV042's MTU size from 'auto' to 'manual' down to 1400 but that didn't help.
I've tried this with different web browsers (Firefox and IE), with the computer firewall off and as well disabling the firewall on the RV042. No change.
Anybody have any clues?