Hi,

I've got a Linux machine where ping doesn't seem to resolve a hostname
if the full domainname isn't specified. Other programs do fine. For
instance:

$ ping frogger
ping: unknown host frogger

$ ping frogger.cssm.iastate.edu
PING frogger.cssm.iastate.edu (129.186.6.75) 56(84) bytes of data.

======

$ telnet frogger
Trying 129.186.6.75...
telnet: connect to address 129.186.6.75: Connection refused
$ telnet frogger.cssm.iastate.edu
Trying 129.186.6.75...
telnet: connect to address 129.186.6.75: Connection refused

Any ideas appreciated.

-- Andrew Bell
andrew.bell.ia@gmail.com

In article <1191427807.683779.81530@o80g2000hse.googlegroups. com>,
"andrew.bell.ia@gmail.com" <andrew.bell.ia@gmail.com> wrote:

> Hi,
>
> I've got a Linux machine where ping doesn't seem to resolve a hostname
> if the full domainname isn't specified. Other programs do fine. For
> instance:

What's in your /etc/resolv.conf, and what does the "hosts" line of
/etc/nsswitch.conf contain?

>
> $ ping frogger
> ping: unknown host frogger
>
> $ ping frogger.cssm.iastate.edu
> PING frogger.cssm.iastate.edu (129.186.6.75) 56(84) bytes of data.
>
> ======
>
> $ telnet frogger
> Trying 129.186.6.75...
> telnet: connect to address 129.186.6.75: Connection refused
> $ telnet frogger.cssm.iastate.edu
> Trying 129.186.6.75...
> telnet: connect to address 129.186.6.75: Connection refused
>
> Any ideas appreciated.
>
> -- Andrew Bell
> andrew.bell.ia@gmail.com

--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***

On Oct 3, 8:48 pm, Barry Margolin <bar...@alum.mit.edu> wrote:
> In article <1191427807.683779.81...@o80g2000hse.googlegroups. com>,
>
> "andrew.bell...@gmail.com" <andrew.bell...@gmail.com> wrote:
> > Hi,
>
> > I've got a Linux machine where ping doesn't seem to resolve a hostname
> > if the full domainname isn't specified. Other programs do fine. For
> > instance:
>
> What's in your /etc/resolv.conf, and what does the "hosts" line of
> /etc/nsswitch.conf contain?

After I posted this I realized that this was probably the wrong group
- apologies, but thanks for the reply. Here are answers to your
questions (and more).

$ cat /etc/resolv.conf
search cssm.iastate.edu iastate.edu
nameserver 129.186.142.200
nameserver 129.186.140.200
nameserver 129.186.1.200

$ cat /etc/nsswitch.conf | grep hosts
hosts: files dns

$ cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 localhost

172.16.11.2 galaga-pvt.cssm.iastate.edu galaga-pvt
172.16.11.3 digdug-pvt.cssm.iastate.edu digdug-pvt
172.16.11.4 qbert-pvt.cssm.iastate.edu qbert-pvt
172.16.11.5 frogger-pvt.cssm.iastate.edu frogger-pvt
172.16.11.6 pacman-pvt.cssm.iastate.edu pacman-pvt

$ nslookup frogger
Server: 129.186.142.200
Address: 129.186.142.200#53

Name: frogger.cssm.iastate.edu
Address: 129.186.6.75

I'm trying to thing of a reason why ping would use some different
resolution mechanism than ssh. Could this be an IPv4 vs. IPv6 thing?

Thanks in advance,

-- Andrew Bell
andrew.bell.ia@gmail.com

On Oct 4, 6:59 am, "andrew.bell...@gmail.com"
<andrew.bell...@gmail.com> wrote:
> On Oct 3, 8:48 pm, Barry Margolin <bar...@alum.mit.edu> wrote:
>
> > In article <1191427807.683779.81...@o80g2000hse.googlegroups. com>,
>
> > "andrew.bell...@gmail.com" <andrew.bell...@gmail.com> wrote:
> > > Hi,
>
> > > I've got a Linux machine where ping doesn't seem to resolve a hostname
> > > if the full domainname isn't specified. Other programs do fine. For
> > > instance:
>
> > What's in your /etc/resolv.conf, and what does the "hosts" line of
> > /etc/nsswitch.conf contain?
>
> After I posted this I realized that this was probably the wrong group
> - apologies, but thanks for the reply. Here are answers to your
> questions (and more).
>
> $ cat /etc/resolv.conf
> search cssm.iastate.edu iastate.edu
> nameserver 129.186.142.200
> nameserver 129.186.140.200
> nameserver 129.186.1.200
>
> $ cat /etc/nsswitch.conf | grep hosts
> hosts: files dns
>
> $ cat /etc/hosts
> # Do not remove the following line, or various programs
> # that require network functionality will fail.
> 127.0.0.1 localhost
>
> 172.16.11.2 galaga-pvt.cssm.iastate.edu galaga-pvt
> 172.16.11.3 digdug-pvt.cssm.iastate.edu digdug-pvt
> 172.16.11.4 qbert-pvt.cssm.iastate.edu qbert-pvt
> 172.16.11.5 frogger-pvt.cssm.iastate.edu frogger-pvt
> 172.16.11.6 pacman-pvt.cssm.iastate.edu pacman-pvt
>
> $ nslookup frogger
> Server: 129.186.142.200
> Address: 129.186.142.200#53
>
> Name: frogger.cssm.iastate.edu
> Address: 129.186.6.75
>
> I'm trying to thing of a reason why ping would use some different
> resolution mechanism than ssh. Could this be an IPv4 vs. IPv6 thing?
>
> Thanks in advance,
>
> -- Andrew Bell
> andrew.bell...@gmail.com

Just a suggestion..

Try running "strace" on the ping to see what the resolver library is
adding to it.
That might give you an idea.

Like:
strace ping frogger.