Intradomain DNS Anycast revisited

Joe Shen joe_hznm at
Fri Mar 25 04:49:56 UTC 2005


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 :


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 ( 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
by OSPF ( our border router inject default route into
OSPF ); there should be
two equal cost path to 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?


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