DNS on cube

From Netsoc Wiki
Jump to: navigation, search

The information on this page is outdated

DNS on cube

Cube runs two DNS servers. One is an recursive DNS server, authoritative for the netsoc.tcd.ie and netsoc.ie zones. It runs as a chrooted instance of BIND on cube.netsoc.tcd.ie.

The other server is a private, netsoc-only DNS cache, which runs on ldap.netsoc.tcd.ie. All containers on cube have ldap.netsoc.tcd.ie as their nameserver in /etc/resolv.conf . The purpose of the cache is to reduce unnecessary duplicate DNS requests made from cube to College, as well as to perform some CNAME trickery to get around our single-externally-routable-IP problem.

in /etc/pdnsd.conf, we poison the netsoc.tcd.ie zone with local CNAMEs pointing cubewww.netsoc.tcd.ie and userweb.netsoc.tcd.ie their respective containers on cube. This ensures that {cubewww,userweb}.netsoc.tcd.ie resolve to cube.netsoc.tcd.ie (our only externally routable IP address) outside cube (since that's what they're defined to do by our authoritative DNS), but resolve to the correct container inside cube (this means, for example, that the website can be viewed inside the login VM at the address www.netsoc.tcd.ie)