It has been my experience in the deployment of such anycasted dns server pods that pushing ospf from the dns server hosts introduces complexity and reduces reliability to the point that other, simpler solutions become much more attractive. You should also take a moment to take a look at your spanning tree configuration, depending on how you care configuring your switches. matto On Fri, 25 Mar 2005, Joe Shen wrote: I'm trying to set up a anycast DNS server farm for customer service. In order to improve availability, we plan to install those servers in one LAN which has the similar structure like : server-(1,3)---switch1---router-1---(outside) | | server-(2,4)---switch2---router-2---(outside) The four unix servers are all unix boxes, switch-1 & switch-2 are interconnected to guarantee the availability. BIND is to be used as DNS cache server software, Quagga OSPFD is used to be routing software. According to above configuration, both routers will know multiple paths to dns cache server, while dns cache server should know two paths to outside network. Here comes my questions: 1) should each dns cache server be configured a static default route (0.0.0.0/0.0.0.0)? If server-(1,3) is configured statically to use router-1 as default router, will Quagga make it use router-2 when router-1 is not reachable? 2) If each server is configured two default router ( router-1 & router-2), or each server learn route 0.0.0.0/0.0.0.0 by OSPF ( our border router inject default route into OSPF ); there should be two equal cost path to 0.0.0.0/0.0.0.0 on each DNS server, the DNS server should disperse any outgoing packets onto the two paths, will that do harm to DNS service ? 3) Is there any requirement on BIND to fit to such multipath routing situation? Joe __________________________________________________ Do You Yahoo!? Log on to Messenger with your mobile phone! http://sg.messenger.yahoo.com --matt@snark.net------------------------------------------<darwin>< The only thing necessary for the triumph of evil is for good men to do nothing. - Edmund Burke