internal network problem

[Zou Min <zoum@comp.nus.edu.sg>]

Hi, all,

There is a LAN consisting several computers, one of which is a Debian linux
machine serving as a gateway server. The gateway server connects to a cable
modem to get into outside network. (I am using ipchains-1.3.10-14 to do the
IP-masquerade)

Recently, there is a strange problem that, when I "ftp 192.168.1.1"
(the gateway server) from 192.168.1.3 (a client computer), it takes an insanely
long time to get the ftp login prompt. (it is a just a internal connection,
and expected to be very fast). This problem also happens to internal telnet, 
ssh connection to the server. 

When doing the above ftp connection, I also ran "tcpdump" to observe 
eth0 (the external interface) at the server. It seems the server try to 
find the hostname for 192.168.1.8 from the DNS server. But I thought there 
should not be DNS-lookup involved.

For the connection to outside network from any client machines, it works 
perfectly. 

Is there any problem with the "ipchians"? (as there internal traffic seems
always to get into the outside network)

TIA.

-- 
Cheers!

Zou Min 
zoum@comp.nus.edu.sg
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