nslookup works, ping <host> replies unknown host

nslookup works, ping <host> replies unknown host

Post by Andreas Wildne » Sun, 27 Feb 2000 04:00:00

Hello list/talk members,

on my Suse 6.2 - kernel 2.2.10 Im having problems looking up hostnames.

nslookup www.suse.com works fine and replies

ping www.suse.com replies unkown host: www.suse.com.

Does ping lookup names somehow different then nslookup? Same behaviour with
telnet, ftp etc - they dont work ether.

dnsquery www.suse.com works.

Any hint for me, where to look and find additional informations on this.


Posted via CNET Help.com


nslookup works, ping <host> replies unknown host

Post by Steve Housem » Sun, 27 Feb 2000 04:00:00

nslookup will use the dns system to lookup names with whichever
nameserver you give it.

ping will (probably) use the libc resolver code (man 5 resolver)
to determine the address. There are several mechanisms that can be used
to resolve addresses ... the /etc/hosts file, nis , dns.
Originally the /etc/host.conf specified the order to use the mechanisms
with the order directive eg
order  hosts,bind

says to use the /etc/hosts file and if not found then use bind ie
dns (using the nameserver specified in /etc/resolv.conf).

It is now confused in some distributions which also use the
/etc/nsswitch.conf file (which contains comments).

So if nslookup works but ping cant find it then I guess that you
have it setup to use either just files or nis.

An strace of ping will show what files are opened and whether the
named is being queried.


Steve Houseman


currently  steve.houseman at * net      


nslookup works, ping <host> replies unknown host

Post by Steve Housem » Sun, 27 Feb 2000 04:00:00

hmmm... just found a post from Malware saying that a problem
with ping returning "unknown host" might be a problem with
"SuSE 6.2 does have without an update of the libnss_dns.so.2
as available on there FTP server ftp.suse.com."


Steve Houseman

currently  steve.houseman at * net      


1. ping <ipv6-host> does not work, ping <ipv6-ip> does


I set up bind 9.2.2 on Sol8 X86.
Configuration seems correct. I can host and dig. I can ping the IP, but
pinging the FQDN gives an error "can not be resolved". Zonefiles can be
transfered correctly from external machines and ping from external
works fine, too.
Someone told me that there could be an issue with the resolver library.

Does anyone have a hint?

Thanks, Helmut

NT Admin on his quest for experience!
Please do not email me, post to the group...

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