Changing repository in openwrt

I have a router flashed to run openwrt (BARRIER BREAKER (Bleeding Edge, r36234)) But opkg can't find packages. According to the error messages and /etc/opkg.conf it seems to be trying to find them at : http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages which is clearly a deprecated address. So where is the new repository? And can I point opkg at it simply by updating the address in the first line of /etc/opkg.conf? (currently : src/gz barrier_breaker http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages )