Ssh can't resolve host name, but the host command can?

Question

I'm having some weird issue that I cannot understand (I'm trying to ssh to alexus and according to ssh it tells me it cannot resolve, yet when i use host to resolve it resolves w/out any issues:

mbp:~ alexus$ ssh -v alexus
OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011
debug1: Reading configuration data /Users/alexus/.ssh/config
debug1: Reading configuration data /etc/ssh_config
debug1: /etc/ssh_config line 20: Applying options for *
debug1: /etc/ssh_config line 53: Applying options for *
ssh: Could not resolve hostname alexus: nodename nor servname provided, or not known
mbp:~ alexus$ host alexus
alexus.XXXXXXXXX.org is an alias for XXX.XXXXXXXXX.org.
XXX.XXXXXXXXX.org has address 10.XX.XXX.XXX
mbp:~ alexus$

How do I troubleshoot this issue?

Do you have anything in `~/.ssh/config` which might point `alexus` to a different IP for SSH? — c4urself, Jan 30 '14 at 16:20
Just in case, in `/etc/resolv.conf` do you have `search XXXXXXXXX.org` ? — NickW, Jan 30 '14 at 16:24
@c4urself : there is nothing in my `~/.ssh/config` that relates to `alexus`. @MadHatter : I don't have `/etc/nsswitch.conf`. @NickW : yes, I do! — alexus, Jan 30 '14 at 16:27
This guy blames it on the glibc resolver.. http://askubuntu.com/questions/149540/host-is-able-to-resolve-a-hostname-ssh-isnt — NickW, Jan 30 '14 at 17:46

score 0 · Answer 1 · answered Jan 30 '14 at 23:49

A quick and dirty way that should resolve the issue is to just add the name to /etc/hosts, like this:

10.XX.XXX.XXX alexus

Other thoughts:

Does ssh -v alexus.XXXXXXXXX.org work? Is alexus.XXXXXXXXX.org a name that resolves on the Internet? If so, does setting up /etc/resolv.conf to use Google's name servers resolve the problem? e.g.

search XXXXXXXXX.org
nameserver 8.8.8.8
nameserver 8.8.4.4

Also, what do the name servers say when directly connected? What does "dig @10.1.2.3 alexus.XXXXXXXXX.org" give you (replace 10.1.2.3 with the actual IP of the DNS server you are using)? How about "dig @10.1.2.3 alexus.XXXXXXXXX.org AAAA"?

if hostname is dns resolvable then there is no need to add anything to hosts file.. — alexus, Aug 03 '15 at 13:53

Ssh can't resolve host name, but the host command can?

1 Answers1