[SOLVED] how to connect two networks using 2 NIC linux pc

laginagesh · 06-14-2010, 08:02 AM

hi,
We have two networks,one is 10.0.0.* with mask 255.255.255.0 & the other 20.0.0.* with mask 255.255.255.0 and one linux(RHEL5) PC with two network interface eth0,eth1.(configured as Router)
eth0 is 10.0.0.1 and eth1 is 20.0.0.1
we have enabled IP_Forward using "sysctl w net.ipv4.ip_forward=1"
cat /proc/sys/net/ipv4/ip_forward is 1
but unable to ping from one network to other network.

two networks are connected to Linux PC.(10.0.0.1 & 20.0.0.1)

still wht configuration required to establish the connection between two networks using LINUX PC.

from router(linux PC) both network PC's are pinging but not from one network to other network.

cheers
Nagesh

nimnull22 · 06-14-2010, 08:26 AM

Can you ping router (GW) 10.0.0.1 from client box with ip=10.0.0.x? And can you ping router (GW) 20.0.0.1 from client with ip=20.0.0.x?

laginagesh · 06-14-2010, 08:32 AM

i am able to ping router IP 10.0.0.1 from 10.0.0.*
20.0.0.1 from 20.0.0.*
20.0.0.* to 10.0.0.1
10.0.0.* to 20.0.0.1
but unable to ping 10.0.0.* to 20.0.0.*

cheers
Nagesh

nimnull22 · 06-14-2010, 08:40 AM

What is output of:
iptables-save
executed on your route?
If possible, please post it here without any confidential information.

laginagesh · 06-14-2010, 08:56 AM

i have executed iptables-save command on router PC
no output.

rn_ · 06-14-2010, 09:19 AM

sorry didn't read your full post before posting my response, please ignore.

rn_ · 06-14-2010, 09:23 AM

did you set a route from 10.0.0.x to 20.0.0.x via 20.0.0.1 and the other way round on your box?

nimnull22 · 06-14-2010, 09:57 AM

Please, execute on route:
1. lsmod | grep ip
2. chkconfig | grep fire
3. chkconfig | grep ip

Last two need root console.
Post output here, please if will be any.

laginagesh · 06-15-2010, 12:21 AM

Please see the output in the attached file.

Regards
Nagesh

laginagesh · 06-15-2010, 12:40 AM

OUTPUT

Quote:

[root@middle sysconfig]# lsmod | grep ip
ib_ipoib 47845 0
ib_sa 24821 5 ib_srp,rdma_cm,ib_cm,ib_local_sa,ib_ipoib
ib_core 50625 14 ib_iser,rdma_ucm,ib_ucm,ib_srp,ib_sdp,rdma_cm,ib_cm,iw_cm,ib_local_sa,ib_ipoib,ib_sa,ib_uverbs,ib_um ad,ib_mad
ipv6 251393 16
dm_multipath 21577 0
dm_mod 58457 2 dm_mirror,dm_multipath

[root@middle sysconfig]# chkconfig --list | grep fire
[root@middle sysconfig]# chkconfig --list | grep ip
hplip 0:off 1:off 2:on 3:on 4:on 5:on 6:off
ip6tables 0:off 1:off 2:on 3:on 4:on 5:on 6:off
ipmi 0:off 1:off 2:off 3:off 4:off 5:off 6:off
iptables 0:off 1:off 2:on 3:on 4:on 5:on 6:off
multipathd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
ripd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
ripngd 0:off 1:off 2:off 3:off 4:off 5:off 6:off

cheers
Nagesh

frandalla · 06-15-2010, 01:33 AM

I think what you have to do is to create a route saying that if something comes to 10.0.0.* it should go to eth0 and if something comes to 20.0.0.* it should go to eth1.
Imagine you have to groups separated by river. You need a bridge to let the people go from one side to the other. It's the same with your two interfaces.

something like:

route add -net 10.0.0.0 eth0
route add -net 20.0.0.0 eth1

nimnull22 · 06-15-2010, 08:39 AM

Code:

[root@middle sysconfig]# chkconfig --list | grep ip
iptables 0:off 1:off 2:on 3:on 4:on 5:on 6:off

Iptables is enabled and works.

Please, on root console type:
iptables
and twice press on TAB button, bash should give you choices among them should be "iptables-save"
Execute it on root console. We need to know all iptable rules, and FORWARD chain as well. Because forward chain will be used to transfer packets between interfaces.

Also please post output WITHOUT any private ip addresses of:
route -n

Thanks.

laginagesh · 06-16-2010, 06:44 AM

Thanks for reply..
problem got solved..i have not added default route in client PC's
After adding default route as
10.0.0.* computers--> route add default 10.0.0.1 netmask 255.0.0.0
20.0.0.* computers--> route add default 20.0.0.1 netmask 255.0.0.0

finally my setup is working...

is there any way to establish connection between networks without adding default route.
dynamic routing.

cheers
Nagesh