resolv.conf, NetworkManager, no ping response on one nameserver

[Steven Stern]

On 05/17/2010 08:08 PM, jackson byers wrote:
> resolv.conf, NetworkManager, no ping response on one nameserver
> 
> 
> byers at f12 ~]$ uname -r
> 2.6.32.11-99.fc12.i686.PAE
> this is a wired box, no wless
> router at 192.168.2.1,
> eth0 presently using static ip 192.168.2.8,
> but that is recent change from previous dhcp 192.168.2.100
> 
> I don't think that change is causing my ping symptoms:
> 
> 
> byers at f12 ~]$ cat /etc/resolv.conf
> # Generated by NetworkManager
> search pacbell.net
> nameserver 206.13.20.12
> nameserver 206.13.31.12
> nameserver 68.94.156.1
> 
> the first one fails to respond to ping
> while the next two respond to ping ok:
> 
> 
> [byers at f12 ~]$ ping -c 5 206.13.20.12
> PING 206.13.20.12 (206.13.20.12) 56(84) bytes of data.
> 
> --- 206.13.20.12 ping statistics ---
> 5 packets transmitted, 0 received, 100% packet loss, time 14000ms
> 
> 
> [byers at f12 ~]$ ping -c 5 206.13.31.12
> PING 206.13.31.12 (206.13.31.12) 56(84) bytes of data.
> 64 bytes from 206.13.31.12: icmp_seq=1 ttl=249 time=47.4 ms
> 64 bytes from 206.13.31.12: icmp_seq=2 ttl=249 time=48.2 ms
> 64 bytes from 206.13.31.12: icmp_seq=3 ttl=249 time=46.1 ms
> 64 bytes from 206.13.31.12: icmp_seq=4 ttl=249 time=46.9 ms
> 64 bytes from 206.13.31.12: icmp_seq=5 ttl=249 time=47.2 ms
> 
> --- 206.13.31.12 ping statistics ---
> 5 packets transmitted, 5 received, 0% packet loss, time 4051ms
> rtt min/avg/max/mdev = 46.114/47.217/48.293/0.725 ms
> 
> 
> [byers at f12 ~]$ ping -c 5 68.94.156.1
> PING 68.94.156.1 (68.94.156.1) 56(84) bytes of data.
> 64 bytes from 68.94.156.1: icmp_seq=1 ttl=253 time=44.7 ms
> 64 bytes from 68.94.156.1: icmp_seq=2 ttl=253 time=44.0 ms
> 64 bytes from 68.94.156.1: icmp_seq=3 ttl=253 time=44.1 ms
> 64 bytes from 68.94.156.1: icmp_seq=4 ttl=253 time=45.0 ms
> 64 bytes from 68.94.156.1: icmp_seq=5 ttl=253 time=44.8 ms
> 
> --- 68.94.156.1 ping statistics ---
> 5 packets transmitted, 5 received, 0% packet loss, time 4049ms
> rtt min/avg/max/mdev = 44.065/44.553/45.014/0.470 ms
> 
> Summary:
> I see zero response from ping 206.13.20.12,
> while ping 206.13.31.12 , 68.94.156.1   both look ok
> 
> Is this normal?
> I have been using these same IP for nameservers for years,
> most recently in F10,F11 and now F12.
> Why would NM supply a nameserver that is unresponive to ping?
> 
> pinging 206.13.29.12  and 206.13.30.12   also look ok,
> but neither of these are in the NM resolv.conf
> 
> Am I free to get rid of the one failing ping, 206.13.20.12
> and substitute one of 206.13.29.12 or 206.13.30.12?
> 
> thanks for any advice
> Jack


It looks like the first name server may be down, but the last is working:

$ nslookup
> server 206.13.20.12
Default server: 206.13.20.12
Address: 206.13.20.12#53
> www.ibm.com
;; connection timed out; no servers could be reached
[sdstern at sds-desk ~]$ nslookup
> server 68.94.156.1
Default server: 68.94.156.1
Address: 68.94.156.1#53
> www.ibm.com
Server:		68.94.156.1
Address:	68.94.156.1#53

Non-authoritative answer:
www.ibm.com	canonical name = www.ibm.com.cs186.net.
Name:	www.ibm.com.cs186.net
Address: 129.42.56.216

If this is an issue (e.g., slow to lookup addresses), change your router
(if that's what's providing your name servers via DHCP) to use OpenDNS
or edit resolv.conf to use the servers below.


  208.67.222.222
  208.67.220.220

See http://http://www.opendns.com/welcome/ for more info.

-- 
-- Steve