My office have 2 Internet line (line 1 and line 2)connect via a cisco router 2811 (IOS AdIPvervice), I use route-map to load sharing internet traffic. Route-map, Rouing is ok. But several websites are not accessed, I check as Ping to that website as domain name and ip address are ok.
when I replace cisco router as a modem, that websites are accessed normal.
I have not solved this problem, i think route-map is ok, routing is ok, but dns have problem when use cisco IOS