ping: unknown host www.google.com

[witha_ph]

Hey all - I've run into a problem that I'm unable to diagnose.

I orginially noticed because clamav was having a spastic trying to update it definations.

Basically, I can't seem to resolve any hostnames from my linux box.

> ping www.google.com
ping: unknown host www.google.com

Yet, my DNS seems to be working correctly.. I'm not running my own DNS server, or DHCP - merely using the server my ISP provides.

 
> dig www.google.com

; <<>> DiG 9.3.0 <<>> www.google.com
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64369
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 6, ADDITIONAL: 6

;; QUESTION SECTION:
;www.google.com.                        IN      A

;; ANSWER SECTION:
www.google.com.         515170  IN      CNAME   www.l.google.com.
www.l.google.com.       73      IN      A       66.102.7.147
www.l.google.com.       73      IN      A       66.102.7.99
www.l.google.com.       73      IN      A       66.102.7.104

;; AUTHORITY SECTION:
l.google.com.           83172   IN      NS      d.l.google.com.
l.google.com.           83172   IN      NS      e.l.google.com.
l.google.com.           83172   IN      NS      g.l.google.com.
l.google.com.           83172   IN      NS      a.l.google.com.
l.google.com.           83172   IN      NS      b.l.google.com.
l.google.com.           83172   IN      NS      c.l.google.com.

;; ADDITIONAL SECTION:
a.l.google.com.         83189   IN      A       216.239.53.9
b.l.google.com.         83189   IN      A       64.233.179.9
c.l.google.com.         83189   IN      A       64.233.161.9
d.l.google.com.         83189   IN      A       64.233.183.9
e.l.google.com.         83189   IN      A       66.102.11.9
g.l.google.com.         83189   IN      A       64.233.167.9

;; Query time: 19 msec
;; SERVER: 203.12.160.35#53(203.12.160.35)
;; WHEN: Mon Jul 24 11:46:06 2006
;; MSG SIZE  rcvd: 292

I can reach IP addresses when pinging, but not hostnames. Weirdly enough our email is still functioning quite happily on this box too postfix/courier-imap).

Quite frankly I'm not sure how to procede from here - so any help would be greatly appreciated!

/etc/resolv.conf follows

search xxx.com.au
nameserver 203.12.160.35
nameserver 203.12.160.36

[Kojak]

Try adding the following two lines to /etc/modprobe.conf

alias net-pf-10 off
alias ipv6 off

If you have a firewall running, I would disable that one, too and check the connection again. And finally, if nothing helps, you might need to fine tune the MTU and MRU settings of your network. If you use a router, reset it to factory to the defaults. Maybe that helps.

[witha_ph]

Ok - turns out I had removed the dns option from my hosts entry in nsswitch.conf

I'm a dumbass

At least its all working again now.

[ManishShrestha]

Hi,

I too had the same problem. I could ping Ip address but not hostnames. I corrected my nsswitch.conf file and it worked properly.

Thanks
Manish Shrestha