The UNIX nslookup program can be used to determine a variety of information about machines and domains in the internet. For security reasons, most machines and domains will not respond to all types of querys made by nslookup. Most will respond to the query types described in the following sections.
Here is an example using nslookup to find the address of ub.d.umn.edu. The command typed by the the user is shown with a light blue background.
csdev03 23% nslookup -type=a ub.d.umn.edu Server: netadm.d.umn.edu Address: 131.212.32.32 Name: ub.d.umn.edu Address: 131.212.109.7
Here is an example using nslookup to find the mail exchanger for a network domain. The command typed by the the user is shown with a light blue background.
csdev03 24% nslookup -type=mx tc.umn.edu Server: netadm.d.umn.edu Address: 131.212.32.32 Non-authoritative answer: tc.umn.edu preference = 10, mail exchanger = mhub-w.tc.umn.edu tc.umn.edu preference = 10, mail exchanger = mhub-a.tc.umn.edu tc.umn.edu preference = 10, mail exchanger = mhub-m.tc.umn.edu Authoritative answers can be found from: tc.umn.edu nameserver = hanna.cac.washington.edu tc.umn.edu nameserver = ns-auth-1.umn.edu tc.umn.edu nameserver = ns-auth-2.umn.edu mhub-a.tc.umn.edu internet address = 134.84.119.205 mhub-m.tc.umn.edu internet address = 160.94.23.20 mhub-w.tc.umn.edu internet address = 160.94.160.20 hanna.cac.washington.edu internet address = 140.142.5.5 ns-auth-1.umn.edu internet address = 128.101.101.1 ns-auth-2.umn.edu internet address = 128.101.101.9
Here is an example using nslookup to find the name server for a domain. The command typed by the the user is shown with a light blue background.
csdev03 26% nslookup -type=ns mit.edu Server: netadm.d.umn.edu Address: 131.212.32.32 Non-authoritative answer: mit.edu nameserver = W20NS.mit.edu mit.edu nameserver = STRAWB.mit.edu mit.edu nameserver = BITSY.mit.edu Authoritative answers can be found from: BITSY.mit.edu internet address = 18.72.0.3 csdev03 27% nslookup -type=ns edu Server: netadm.d.umn.edu Address: 131.212.32.32 Non-authoritative answer: edu nameserver = H3.NSTLD.COM edu nameserver = L3.NSTLD.COM edu nameserver = M3.NSTLD.COM edu nameserver = A3.NSTLD.COM edu nameserver = C3.NSTLD.COM edu nameserver = D3.NSTLD.COM edu nameserver = E3.NSTLD.COM edu nameserver = G3.NSTLD.COM Authoritative answers can be found from: C3.NSTLD.COM internet address = 192.26.92.32 D3.NSTLD.COM internet address = 192.31.80.32 M3.NSTLD.COM internet address = 192.55.83.32