Installing and Administering Internet Services

142 Chapter3
Configuring and Administering the BIND Name Service
Troubleshooting the BIND Name Server
5. Network connectivity problems may cause certain lookups to fail. See
the Installing and Administering LAN/9000 Software manual for
information on troubleshooting network connectivity.
• Name server debugging output
Turn on debug level 1. ping the host name. Check the name server
debugging output in /var/tmp/named.run for lines like this:
req: found 'cucard.med.columbia.edu' as 'columbia.edu'
resend(addr=1 n=0) -> 128.59.32.1 6 (53) nsid=18 id=1 0ms
resend(addr=2 n=0) -> 128.59.40.130 6 (53) nsid=18 id=1
0ms
resend(addr=3 n=0) -> 128.103.1.1 6 (53) nsid=18 id=1
764ms
In this case the name server is trying to contact the columbia.edu
name servers but is not getting a response. Check network
connectivity by pinging the addresses the server is trying to
contact.
If the addresses being tried are the root name servers, either the
host does not have connectivity to these machines, or the root
server addresses are wrong.
• nslookup
nslookup times out while trying to look up the name.
• ping hostname
A message is returned saying that the host is unknown.
6. Secondary master is unable to load from another master. This may be
caused by a configuration error or problems with network
connectivity. Check that the domain being loaded and the address of
the remote server are correct in the boot file.
• syslogd
An error message is logged indicating the master server for the
secondary zone is unreachable.
• Name Server debugging output
Start the secondary server at debugging level 2 or 3. Watch for
error messages in the debug output. These could show that the
other server is unreachable, the other server is not authoritative
for the domain, or the local SOA serial number is higher than the