We have two 2820s, with the latest 3.3.3 firmware (also tried with 3.2.1) and have set it up so that site A dials in to site B. Everything seems to work OK - site B can ping various PCs at site A, and log into site A's router. However, no other traffic seems to get through - I cannot for example access a file share at site A or log in to an IP phone at site A.

We have isolated it as being a problem with Site A, as I've set up two other VPNs lan-lan connections from my home router (also a 2820) to site A and to Site B respectively and the problem only exhibits itself with site A - I cannot access anything at that site (except with ping, which works fine).

At site A it's set up with:
My WAN IP 0.0.0.0
Remote Gateway IP 0.0.0.0
Remote Network IP 192.168.3.0
Remote Network Mask 255.255.255.0
RIP Direction TX/RX Both (we've tried none)
From first subnet to remote: Route

and my home router:
My WAN IP 0.0.0.0
Remote Gateway IP 0.0.0.0
Remote Network IP 192.168.49.0
Remote Network Mask 255.255.255.0
RIP Direction TX/RX Both (we've tried none)
From first subnet to remote: Route

The VPN is set to PPTP.

Does anyone have any ideas at all? The main point is that while one site can ping anything at the remote site OK, it is only able to access the router at the remote site (via http) - any other traffic simply doesn't get through.[/b]

I have a similar issue, though with the firmware version shipped with the unit I could share files if using the IP address, since being asked to upgrade firmware that has now ceased. I can Ping using IP's but not machines names at all across the VPN (tried IPsec and PPTP).
Under the shipped firmware I could see some machines names but intermittently and unreliably, now I can't even see the machine names.

I have one other issue, one of the routers crashes every 3-7days, in that it looses cables net connections (ie all ports lights die and PC's can't see router) and seconds later the WiFi drops then the ADSL drops, so can't access the router via any method (even remotely). The Other unit reboots randomly, no sure how often but at least 1/week ... Do you have these issues as well?

Draytek UK support have spent >3 weeks on this and got basically nowhere, we are now trying two new 2820Vn's incase there is a hardware issue (bad QA in manufacture?) but otherwise everyone is stumped!

I like to spec of the 2820Vn's and would rather stick with them, but if this fails to fix the issue I'll be back with Netgear ... but that leaves me needing to split my failover 3G or WiFi or VPN solution from a single box into either 2 or 3 separate bits of hardware ... unless anyone can recommend a solution?

I have checked my machines configurations and all seem in order, it is only a small network (2-3 PC's each site), but welcome any config checks I can do to make sure it is not something else ... There is no server and DCHP is being provided by the routers, it is just a peer to peer setup right now (2 Win Server 2008R2 going in shortly along with 20 client PC's so need to get issues resolved ASAP).

Try a teleworker PPTP VPN to see if the results are any different. If they are then perhaps it's due to firewall rules on the PC that's being accessed because a teleworker PPTP would, from the accessed PC point of view, be on the same IP range. Where as a LAN-to-LAN VPN is on a different IP range.