Background: I'm using a Linksys WRT610Nv2 with (Shibby) tomato-K26USB-1.28.RT5x-MIPSR2-087V-Big-VPN. My idea was (still is) to create a guest wireless network by using my old AR670W (running a DD-WRT build) as a wireless attach point going into a new virtual LAN on port 4 of the WRT610N.
There seem to be a few issues with this, some no doubt 'pilot error', and possibly some bugs in tomato software.
The first issue: I create a new bridge (br1, using the GUI), and then create a new VLAN3 associated with port 4 (LAN1-br1, again using the GUI). Save and reboot. The association between LAN and eth2 (the 5GHz radio device) disappears on VLAN1. So the 2.4 GHZ works fine, but the status page shows the 5.2 GHz interface DOWN - and it is.
The situation is remedied by inserting some code in the Administration -> Scripts -> init:
nvram set lan_ifnames="vlan1 eth1 eth2" ifconfig eth2 up
This seems to be a bug. Creating a new bridge and VLAN should not break the existing association between the original LAN and the 5 GHz radio.
Not an urgent problem, as long as a work-around has been found. Having this fixed will save the next people to try it a good deal of problem solving time.