Well a week down the line and no further problems so I've done a couple more now. The number of sessions shown under NAT sessions (Diagnostics - NAT sessions table) and (Diagnostics - data flow monitor - sessions) seem to be related to each other but bear no relationship at all to the sessions reported by Firewall - general setup which is the one that was causing my problems. Changing the session timeout from the default 1440 minutes down to something more realistic (For us) like 60 minutes certainly seems to have resolved it

Only 2 more to do now - both in remote locations so I'll leave them a week or so just to double check there are no further problems...

Thanks for the help offered and hopefully anybody else having the same issues will come across this post and it will help them as well

We've had the exact same problem on two of our routers now. They both come close to the 15,000 session limit and then start showing users these errors.

It also seems to stop new WAN traffic going over the VPN. Prime example is when a user prints over the VPNs the job never arrives as the router is blocking the new data connection. We have been restarting the routers to cure the issue but now reading this thread i have reduced the session time out to 90 minutes. I hope this doesn't drop our WAN traffic connections every 90 minutes or our Citrix users maybe mad!!

Liam

Was a solution found? I'm hitting 11000 sessions after a day or so. Started after upgrading 2710 to 3.6.9.

This probably won't help Jaked but I now have the same problem with my own 2710n and also on a customers router. This all seemed to start after a firmware upgrade. I have been in touch with Draytek UK support and have been advised to try a different version of the firmware. I have tried this and now it is definitely accumulating the session count. As soon as it hits 11,000 up comes the error message for the users.

My current sessions bear no relation to the session count under the Firewall section. I have emailed support today to say that the firmware update has not resolved this issue. I look after quite a few Draytek routers and have checked a few of my customers devices. The one 2710 I looked at appears to have the same problem but with only one user most of the time I suspect it has never reached the 11,000 limit before it gets rebooted or turned off. All the others looked completely right and had a session count in the Firewall section that was very close to the total for the sessions shown under the Traffic Monitor.

I will probably have to decrease the default session time-out to something much shorter simply to try and avoid having to reset the router several times a day. Hopefully this will get sorted out with another firmware update.

I have the same problem on my 2710n having upgraded to the latest firmware {3.6.9). It didn't do it under the previous firmware version in an otherwise identical environment.

I'm really disappointed to find that with the newest firmware on a 2710, it still has the same bug in the firewall sessions limit.

I reverted back to a much older firmware version a few months ago and that version worked correctly. Having tried several newer versions only to find that all of them had the same bug I just went back to my last known working version. Not great but it helped to keep me sane.

I had hoped that the newest version would be fixed as I have made Draytek UK aware of this problem. I was wrong. The current version, 3.7.0 is showing the same problem. As soon as I have time I will inform Draytek support that this version still shows the same issue. To be fair to the UK guys, they have at least been interested but the only solution seems to be to roll back to an older version. I will update this post with the version number that works once I have downgraded the 2710.