We have a Redhat 7 Linux server acting as the gateway and firewall for our office network. We recently upgrade our DSL line to a new higher speed, which means we have new static IP addresses and new DNS servers, and a new DSL Modem/Router with a new gateway address. I'm trying to get our server to route email, host the website, and route internet traffic through the new DSL line. I tried editing the following files:

/etc/hosts
/etc/resolv.conf
/etc/sysconfig/network
/etc/sysconfig/network-scripts/ifcfg-eth1 (ifcfg-eth0 is for our internal network, and I don't think it needs to change)

I changed the addresses in those files, but it didn't seem to work. Are there some configuration files that I'm missing that I need to change? Anywhere else that might tell the server what it's IP address is and how to route traffic? Any help would be greatly appreciated.

The current server configuration is doing everything we need to do and working great plugged into the old DSL line. It simply doesn't route traffic when switched to the new line.

make sure about network configuration.
u can check them with followings:
ifconfig
route -n
etc...

and your firewall configuration?? probably your firewall-NAT script is generated for old network configuration. so u will probably have to reconfigure it. and u have an old version of redhat. what does it use for firewalling/NAT ?
i think it has ipchains. check the output of followings.
#rpm -qa |grep ipchains
#rpm -qa |grep iptables
#rpm -qa|grep ipfwadm

if u have iptables, i can help u about it. if it isnt, sorry i dont know others

good luck.

Maxut: Thanks for your rapid response. I do have iptables installed, but it turned out to be easier than I thought.

Since everything was already configured correctly, I just used grep to locate all instances of the old domain ip, old DNS ips, and old Gateway ip. I edited all those files, and viola, it worked. I ended up having to edit the following files, if anyone else runs into this problem:

/etc/hosts
/etc/resolv.conf
/etc/sysconfig/network
/etc/sycsonfig/network-scripts/ifcfg-eth1
/etc/portsentry/portsentry.ignore
/etc/rc.d/rc.firewall

Thanks for the response.

good
thnx for posting the easy solition.