Hi,

I am very new to linux. I have to build a netwrok for small lab and office setup.


Setup as below
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I have a PC running with Centos 5.4 and has 4 NIC cards. eth0, eth1, eth2 and eth3.

eth0 --- Connected to DSL and getting the Public IP address using PPPoE.
eth1 --- 192.168.4.1 statically configured on the interface
eth2 --- 192.168.5.1 statically configured on the interface
eth3 --- 192.168.6.1 statically configured on the interface



I have
Host1 conncted behind eth1 (host1) which has static IP address
192.168.4.10/24 and GW 192.168.4.1 and DNS: same as from PPPoE

Host2 conncted behind eth2 (host2) which has static IP address
192.168.5.10/24 and GW 192.168.5.1 and DNS: same as from PPPoE

Host3 conncted behind eth2 (host3) which has static IP address
192.168.6.10/24 and GW 192.168.6.1 and DNS: same as from PPPoE

Config
=======
ip_forward is enabled on the CentOS machine
iptable is configured as belwo,
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE


Issue
=====

Now host1 can able to talk to host2 and host3 and also it can reach eth0 and DNS server IP is reachable. Even it can ping any public NTP server or ftp server IP address.

But when I ping ping google.com its not able to resolve.

This is even tru for other hosts host2 and host3.
I want all the hosts access internet and able to browse.

At the same time I can ping google.com from the eth0 from centOS machine.

All hosts are Windows PC (host1, hots2 and host3)

Please let me know what is the issue here.

if you are using pppoe then your outbound interface may be ppp0 that is where you should be doing the masquarading.

Sorry, It was my mistake... I did masqurade on pppoe itself

Hi,

I did install yum install chaching-nameserver on the machine and problem is resloved.