Entry

Is there something special about the @ file? I want to list ORSC servers there.

How do I configure djbdns to use alternate servers for some domains? (eg: OpenNIC)

Aug 29th, 2001 14:25
Brian Coogan,

Is there something special about the @ file?
Are the IP addresses in there checked in some order?
Answer:
The addresses in the @ file are chosen randomly and only the first 16 
entries are ever used. The default @ file curently contains 13 servers, 
so appending the ORSC servers to the file means you have only a 3/16 
chance of getting an ORSC server on each attempt (assuming the first 
root server contacted always responds)!
There are 12 ORSC servers, so if you list them at the top and leave the 
ICANN servers there, you'd have a 12/16 chance of getting an ORSC 
server on each attempt!
In other words, you shouldn't mix entries in the @ file.  Use all of 
the ORSC servers, or all of the ICANN servers, but not both.  If you 
follow this rule you can use either the ICANN servers or the ORSC 
servers.
The ORSC instructions for setting up dnscache to use the ORSC servers 
are here:
  http://support.open-rsc.org/How_To/unix/djbdns
A smart alternative to using the @ file is to delegate the required 
TLDs to the ORSC servers - an excerpt from the excellent Kuro5hin 
article (see articles links on main page) on setting up DNS follows 
(this example's for OpenNIC):
"   Configuring dnscache for using alternate name servers for some 
domains is easy. You merely add a file to '/etc/dnscache/root/servers' 
which is named for the zone (such as 'thock.com'), and contains IPs of 
authoritative name servers on each line. OpenNIC was an idea proposed 
on Kuro5hin, which later became a reality. The following example 
scriptlet sets up dnscache to work with OpenNIC:
  #!/bin/sh
  cd /etc/dnscache/root
  # Note: I have modified these slightly from the ones on OpenNIC's
  # page to have the format which dnscache wants.
  wget http://web.thock.com/Dylan/dns/opennic.tlds
  wget http://web.thock.com/Dylan/dns/opennic.servers
  cd servers
  cat ../opennic.tlds | xargs -l ln ../opennic.servers 
  svc -t /service/dnscache
  echo Done!
Ping ns1.dev.null to be sure it works."
The advantage of delegating the TLDs like this is that you can mix and 
match nameservers in a really very flexible manner, for instance, you 
could intermix ICANN, ORSC and OpenNIC servers as appropriate.
-- Rob Mayoff/Brian Coogan  June 2001