Dnswalk is a DNS debugger. It performs zone transfers of specified domains, and checks the database in numerous ways for internal consistency, as well as accuracy. dnswalk requires perl and the Net::DNS Perl package. If you do not have these, get them. (perl is assumed to be in /usr/local/bin, edit the first line of dnswalk if it is not)
-r Recursively descend sub-domains of the specified domain.
-a Turn on warning of duplicate A records.
-d Print debugging and ‘status’ information to stderr. (Use only if redirecting stdout).
-m Perform checks only if the zone has been modified since the previous run.
-F Perform “fascist” checking. When checking an A record, compare the PTR name for each IP address with the forward name and report mismatches.
-i Suppress check for invalid characters in a domain name.
-l Perform “lame delegation” checking. For every NS record, check to see that the listed host is indeed returning authoritative answers for this domain.
cyborg@cyborg:~$ dnswalk -d ztrela.com. Checking ztrela.com.