1. Goal
We're introducing anycast as mechanism to increase the availability of
a server, in this case a DNS server.
We're interested in seeing anycast workin and at the moment we're not
so much interested in which routing protocol is being used. We'll use
RIP because it is easy.
We're also not so much interested in security (at first at least), so forget
the enable password, the banner and ssh for the moment.
Also, we're using /24 networks for simplification so I don't have
to calculate netmasks.
1.1. Network layout
Two data centres are connected through an ethernet-like interface (I don't
need the trouble of a serial link in this lab). Both data centres have a
DNS server (xenial1 and xenial2) and both have a DNS client (xenial3 and xenial4).
Between the datacentres there are routers, and the DNS server is behind a
second router.
1.2. Steps
We'll go through the configuration in different steps:
-
set-up the network in GNS3
-
set-up the DNS-servers on the Debian
-
verify that it works with unicast DNS calls
-
set-up any-cast
1.3. Versions
1
|
february 2016
|
based on debian
|
2
|
april 2018
|
introduced vagrant; precise server and fedora clients
|
3
|
february 2020
|
all machines to xenial; no more tap-devices (all vboxnet)
|