Draytek Support - we really could do with a fix on this issue (3.3.3/3.3.4). It's been broken far too long; this is unacceptable given it was working functionality that was broken with a new release of firmware.

Thanks
Mike

mikeysoft wrote: After liasing with Draytek UK support, I've narrowed this down to a bug in 3.3.3 where "NAT loopback" (as I should have described it in my original post!) breaks when you enable IP routing for an IP address block.

It breaks even if you don't enable IP routing for a second subnet, which is only required if you actually want to assign those IP addresses to machines on the LAN. I have a block of 16 (obviously, only 14 usable) IP addresses, some of which are mapped using port forwarding to a Web server on the LAN that has a "Martian" Class C private address. I moved my 2820 here from another site to replace a 2800 and found that I couldn't access* those Web sites from inside the LAN any more.

It's still broken on 3.3.4.1 (3.3.4.1_232201) and I was about to try 3.3.5 but I've decided not to for the moment.

* If it helps anyone at Draytek, this isn't strictly true. I experimented because I was getting a timed-out "can't connect" on the browser, so I tried browsing via my own caching proxy inside the LAN. If I keep trying to refresh, and wait a long time, some or all of the pages get served up eventually. But it's very hit-or-miss. Just thought that this might help with the debugging!

Thanks for the reply. I'm still disgusted that something so basic has broken for so long (that used to work!) with no sign of a fix after MONTHS AND MONTHS AND MONTHS.