[lug] ipchains -L hangs

Deva Samartha YTAFTDJAHCWS at spammotel.com
Wed Dec 13 01:55:57 MST 2000

>My ppp0 input chain listed 86 rules in about 6 seconds. They displayed
>in chunks, with pauses between chunks. I believe it is possible the
>pauses were caused by attempting name lookup of a numeric ip that took a
>brief moment. Possibly it is slowed when doing that?

I checked it and - see there - every line in ipchains -L  does a bunch of 
DNS requests to the USwest DNS server which does not make much sense at 
all! I am not very familiar with the tcpdump format below but it looks as 
if it tries to do a reverse address lookup for the

20:31:46.510946 me.mydom.com.1049 > ns2.dnvr.uswest.net.domain: 36691+ PTR? (42)
20:31:46.532356 ns2.dnvr.uswest.net.domain > me.mydom.com.1049: 36691 
NXDomain* 0/1/0 (124)

Same happens when going from the firewall (where the chain resides ) with 
browser to httpd in DMZ with local IP - it hangs too with varying times 
doing DNS lookups on local IP's.

I tried putting names and network addresses in /etc/networks  and rebooted 
- no change of behavior.

/etc/nsswitch has:

networks:       files dns

Any suggestions of what to do in order to talk the programs into dropping 
their DNS weirdness?

Thank you

Boobledrops ( Samartha )

More information about the LUG mailing list