Firmware: 3.3.7.7_232201
Build date: Jan 6 2016 11:50:15

Hi,
I've recently dusted off my old 2820n having had enough of virgin's super hub 2 wifi issues. I've upgraded the firmware but every couple of days I'm getting these max session limit reached error messages even when i've not set one up. I have reboot the router to clear it.
I've tried telnet-ing in and setting the life time of each session as advised on various sites:

portmaptime -t 60

But to no avail. I'm using the 2820 on WAN2 with the Super Hub as a cable modem.

Anybody else having this problem? Is it safe to downgrade the firmware to a year ago?

Firmware Version : 3.3.7.7_2471201
Build Date/Time : Jan 6 2016 11:54:18

Same problem here using WAN1.
The only solution is reboot router or downgrade firmware to previous version.

Well it's good to know I'm not the only one affected and it's not just my settings.
The limit bug does seem like it's a memory leak. Its definitely worse during half term as the kids are at home. There was one day this week that I had to reboot the router twice!
I've not been on torrents and the kids are just on the PS4 and Steam. So it's unusual that I could easily rack up so many IP sessions in a day.
I suppose one of the household laptops could have been hacked to act as a net bot but from the Data Flow Monitor - i've never seen the TOTAL sessions peak beyond 1000. It's around 800~900 sessions before we get the session limit.

But anyway - until a new firmware is released to fix it (which probably is next Feb/Jan as per last couple of releases) then i've scheduled an automatic reboot every night. Hopefully that will keep the kids happy for now.

The default firewall filters is what appears to be causing the session limit. There is a fixed 17000 session limit by default for "call filter" and "data filter".
I don't really understand completely what they are for but i've disabled them both and no session limits for the past few days.

BUT - is my firewall compromised?

Why can't i change the maximum default session limit? I can reduce it but not increase it.

Any help would be much appreciated.

No workaround about session limit issue.
Draytek already know the problem and a new version of firmware (3378) will be released in a few days.

Have a nice day.

That sounds great step19. Thanks for the info.