I have a switch configured to resolve hostnames, it works fine, if I ping xxx.xxx.local or whatever it looks up the IP and displays output.
Can this be done in reverse? So If I find an IP address in the arp table and want to resolve its hostname, is there a command like Windows nslookup that will allow for this?
There is nothing built-in, but attached is a Tcl script I wrote to do A and PTR DNS lookups using the IOS tclsh (in IOS 12.3(2)T or later, 12.2(18)SXF5 or higher, 12.2(40)SE or higher, etc.). Tclsh doesn't support UDP sockets right now, so my script uses TCP. It works similarly to the UNIX host command. If you do not specify a DNS server, it tries to obtain one by looking at the device's config. The usage is:
host.tcl address [dns_server]
Router#tclsh flash:host.tcl 10.1.1.1
126.96.36.199.in-addr.arpa domain name pointer host.company.com
Router#tclsh flash:host.tcl host.company.com
host.company.com has address 10.1.1.1
The script is pretty simplistic, but it should accomplish what you want.