[TriLUG] Networking questions
Mon, 3 Sep 2001 14:14:23 +0500
I've configured IP masquerading with ipchains on a RH 7.1 box so that I can
use the server's modem from any other machine in the house. I have a few
questions that I was hoping someone could answer so that I don't have to
do any more digging today.
1) I now have nameserver entries in /etc/resolv.conf on the client machines
(all Linux boxes) on my network. When the server isn't connected to the
internet, connections within my internal network are taking a long time. I'd
like to make each box check /etc/hosts before going to a nameserver, but I
can't remember how to do that.
2) I use a laptop at work and home, so I use DHCP to configure its IP address
on both networks. I'm not sure which of the dhcpd.conf options need to be
set so that the laptop can get the correct IP address (the machine with the
modem) for the default gateway. Is it the "routers" option?
3) I was a little confused by the IP Masquerading HOWTO. I have a 2.4.x
kernel but am still using ipchains. In testing, it had me run
echo "1" > /proc/sys/net/ipv4/ip_forward
echo "1" > /proc/sys/net/ipv4/ip_dynaddr
Right now, I've added those lines to /etc/init.d/ipchains, but I thought that
there might be a better way to do it on a Red Hat (7.1) system.
4) The HOWTO also said to
echo "1" > /proc/sys/net/ipv4/ip_always_defrag
but I don't see an ip_always_defrag file in that directory. I'm not sure
what that means, but I would like to defragment all packets coming into my
5) The HOWTO made a passing remark about adding
to /etc/sysconfig/network on a 2.2.x kernel. If I'm using ipchains on a
2.4.x kernel, does that still apply.
I could probably test all of these things myself, but the server that
currently has the modem is also the NFS fileserver. :) I'm trying to avoid
unnecessary reboots since I'd then have to shut down my other machines.