Can't resolve hostname by ip address over nslookup

Question

I've got an Ubuntu Server on my LAN. I can fully use it (samba, ssh, apache2, xmpp...) by using it's ip address. But I want to use the hostname to connect (e.g. ssh). When I do a nslookup with the ip address of the server, the answer is: name = noname (which is NOT the server's hostname ;-) Other hosts on the LAN are responding with the correct hostname.

Output of nslookup 10.0.0.24 (this is my ubuntu server): shows no hostname

Server:     127.0.1.1
Address:    127.0.1.1#53
24.0.0.10.in-addr.arpa  name = noname.

Output of nslookup 10.0.0.21 (this is my raspberryPi): shows the right hostname.

Server:     127.0.1.1
Address:    127.0.1.1#53
21.0.0.10.in-addr.arpa  name = retropie.

All hosts get their ip address over DHCP. So the hosts, who show their hostname correctly were never configured separately.

Of course I have admin rights to my server :) I didn't set up an extra DNS Server. On my LAN there is only a router with connection to my ISP and a few other hosts. Those other hosts are a RaspberryPi and a Windows machine. Both show up the right hostnames when doing nslookup. — bastele, May 13 '16 at 17:39
@Bert What do you mean with registering to my server's DNS ? — bastele, May 13 '16 at 17:42
I'm trying to guess where they come from since it should normally be done through a DNS server. Please provide a full output of one that works to clarify. — Julie Pelletier, May 13 '16 at 17:47
My router recognizes my server and any other host, but he doesn't get the hostname of m ubuntu server. However the router does get the hostname of the raspberryPi and my Windows PC. Full output of nslookup? — bastele, May 13 '16 at 17:50

score 1 · Accepted Answer · answered May 13 '16 at 23:14

For such a small network and without the assumption that there is dns server on this network you can simply add the ip addresses to the local hosts file on each machine. I know this is a bit "old school" but it will be 100% solid and never fail.

The reason dns may failing is that your dhcp server may be providing dns settings for a dns server that either you do not control or one that does not get automatic updates from the dhcp system. If you add a static entry into your (dns server you control whose ip address is given out via dhcp) then you will get the correct nslookup from a cli from any machine on your network.

yes, it seems that ubuntu doesn't provide the hostname over DHCP by default. But because the rasberryPi does it, i search for a solution to also provide the hostname automatically for the DHCP-Server (router) — bastele, May 14 '16 at 07:07

score 0 · Answer 2 · answered May 13 '16 at 17:55

0

There's no automatic system for making your hostname known to the rest of the network. If you have a DHCP server (often on your router in home setups) that might know it (I can see that mine does, but I don't know the DHCP protocol well enough to know how it's done). If you want others to know what IP address a certain name corresponds to, you (typically) have to set up DNS.

answered May 13 '16 at 17:55

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I edited my Question: The router gets the corresponding hostnames automatically for all my hosts but my ubuntu machine(s) – bastele May 13 '16 at 17:59

Can't resolve hostname by ip address over nslookup

2 Answers2