[ltp] DNS Name Resolution incorrect after resume

Vijay Garla linux-thinkpad@linux-thinkpad.org
Tue, 31 May 2005 13:27:23 +0100


Hi,

I have the following problem: DNS Name resolution is simply incorrect 
after resuming from suspend-to-ram or suspend-to-disk on my t40p, 
atheros chipset, with suse 9.2 or 9.3.  DNS Names are simply mapped to 
the wrong IP.  This does not happen with windows (I haven't tested 
ethernet).   After I do a reboot, names are resolved correctly.  The 
strange thing is, restarting nscd doesn't help immediately.  After i 
restart nscd, name resolution is still incorrect; however, after a few 
minutes, names are mapped correctly again.

for example, pop.gmx.net and mx.freenet.de are mapped to the same IP 
after a resume:

vijay@narasimha:~> nslookup pop.gmx.net
Server:         192.168.1.1
Address:        192.168.1.1#53

Non-authoritative answer:
Name:   pop.gmx.net
Address: 213.165.64.20

vijay@narasimha:~> nslookup mx.freenet.de
Server:         192.168.1.1
Address:        192.168.1.1#53

Non-authoritative answer:
Name:   mx.freenet.de
Address: 213.165.64.20

I know that the router (which is also a dns server) is doing the name 
resolution correctly.  The Router is a Siemens Gigaset SE 515 with 
embedded Linux (busybox).  When I log in to the router, and do the same 
name lookups, I see that the names are resolved correctly:

# ping pop.gmx.net
PING pop.gmx.net (213.165.64.20): 56 data bytes
56 data bytes from 213.165.64.20: icmp_seq=0 ttl=245 time=73.3 ms

# ping mx.freenet.de
PING mx.freenet.de (194.97.55.190): 56 data bytes
56 data bytes from 194.97.55.190: icmp_seq=0 ttl=55 time=67.4 ms

Has anybody experienced this problem before?  Does anybody have an idea, 
where I should look?

On a different note: dhcp over wireless lan takes often takes eons with 
linux (upwards of several minutes).  I've worked around this by setting 
up ip, routing, and dns statically, which works fine at home (where 
there are 3 other wlans running).  However, in other noisy environments 
(e.g. airports), I don't get an IP at all.  Why does DHCP take so long, 
even after I've associated with the AP?

TIA,

Vijay