Resolve hostname from IP

cornish · 10-10-2007, 04:24 AM

Simple questions can I resolve a hostname from an IP address

When I work with windows at work I can ping -a to resolve a hostname but I would like to do this with linux?

bathory · 10-10-2007, 04:33 AM

You can use nslookup (deprecated) or dig:

Code:

nslookup xx.xx.xx.xx
dig -x xx.xx.xx.xx

cornish · 10-10-2007, 04:34 AM

Cheers mate I will try that later

cornish · 10-10-2007, 05:07 AM

I tired both of those options but neither of them work

bathory · 10-10-2007, 05:12 AM

Please define "neither of them work". Did the commands ran, or they do not exist? You can also try

Code:

host xx.xx.xx.xx

cornish · 10-10-2007, 05:15 AM

Yes they both ran but neither displayed the hostname afterwards

host didnt work either

bathory · 10-10-2007, 05:36 AM

You should get an answer like this:

Code:

dig -x 209.85.135.147

; <<>> DiG 9.2.2 <<>> -x 209.85.135.147
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 49976
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 4, ADDITIONAL: 0

;; QUESTION SECTION:
;147.135.85.209.in-addr.arpa.   IN      PTR

;; ANSWER SECTION:
147.135.85.209.in-addr.arpa. 86165 IN   PTR     mu-in-f147.google.com.

;; AUTHORITY SECTION:
135.85.209.in-addr.arpa. 86165  IN      NS      ns1.google.com.
135.85.209.in-addr.arpa. 86165  IN      NS      ns4.google.com.
135.85.209.in-addr.arpa. 86165  IN      NS      ns3.google.com.
135.85.209.in-addr.arpa. 86165  IN      NS      ns2.google.com.

;; Query time: 2 msec
;; SERVER: 193.0.0.195#53(193.0.0.195)
;; WHEN: Wed Oct 10 13:29:15 2007
;; MSG SIZE  rcvd: 152

host 209.85.135.147
147.135.85.209.in-addr.arpa domain name pointer mu-in-f147.google.com.

cornish · 10-10-2007, 05:44 AM

I get this

Quote:

mark@nb10001L:/etc$ dig -x 10.179.108.11

; <<>> DiG 9.3.4 <<>> -x 10.179.108.11
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 55919
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;11.108.179.10.in-addr.arpa. IN PTR

;; AUTHORITY SECTION:
10.in-addr.arpa. 600 IN SOA prisoner.iana.org. hostmaster.root-servers.org. 2002040800 1800 900 604800 604800

;; Query time: 44 msec
;; SERVER: 10.179.104.46#53(10.179.104.46)
;; WHEN: Wed Oct 10 11:42:09 2007
;; MSG SIZE rcvd: 121

The host should be myPC

jschiwal · 10-10-2007, 05:45 AM

Cornish might be wanting to do this on his lan without a nameserver running.

Maybe try "arp <ipaddress>" which will return the name and MAC address if the target is listed in the kernel arp table.

If it doesn't exist in the table, you could ping the ip first:

Code:

arp 192.168.1.103
192.168.1.103 (192.168.1.103) -- no entry
> ping -c 1 192.168.1.103
PING 192.168.1.103 (192.168.1.103) 56(84) bytes of data.
64 bytes from 192.168.1.103: icmp_seq=1 ttl=64 time=10.5 ms

--- 192.168.1.103 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 10.551/10.551/10.551/0.000 ms
> arp 192.168.1.103
Address                  HWtype  HWaddress           Flags Mask            Iface
laser                    ether   00:0E:7F:42:6C:65   C                     eth0

cornish · 10-10-2007, 05:52 AM

There is a DNS running on the LAN as I can ping the device via its hostname

farslayer · 10-10-2007, 10:21 AM

is the rDNS entry in the DNS server ? just because it can resolve a forward lookup doesn't mean they setup the reverse..

Your dig query shows 1 Question and 0 Answers.
Dig queried your internal DNS server (10.179.104.46) and your server basically responded "I don't Know"