Network Errors in RH 7.2 500 marks

Is the second NIC a 10/100 card and does it connect to a 10/100 hub or switch? It's possible that the NIC isn't auto-negotiating the correct link speed and mode if the answer to those two questions is yes, which will lead to lots of errors. You could also have a bad cable, NIC or hub/switch port. Most of the time a link speed/mode problem can be solved by forcing one or both ends of the link to the appropraiet mode. How that gets done depends on what hardware is involved.

I'm guessing that question 2 means that you pould ping the IP of the first NIC from a host connected to the network attached to the second nic, but not beyond. Most likely that is because the next router upstream from the first NIC hasn't been told that the "2.x" network is reachable via the IP of the first NIC. Obviously I don't know what that router is, but someone will have to create a static route for the hosts in the "2.x" network to be able to talk to anything on the "1.x" network or further out.

Thnx for ur Suggestions Jlevie! i found the NIC is the problem for the first Issue. Regarding the second let me tell u something more about the setup.


         -------  1.232 ---------- 2.35    -------
         - 1.X -________-  Linux  -________- 2.x -
         -     -        -    Box  -        -     -
         -------        ----------         -------

a, 1.232 is eth0 of linux box
b, 2.35 is eth1 of linux box
c, i have connected one client machine on each network (1.x and 2.x), and from 2.x i can ping 1.232 also from 1.x i can ping 2.35. but nothing more than that point on either side.

i got a cisco 2500 series router on the 1.x network which connects to outseide world.

now do i have to add route in the linux box ?
FYI i have added one route like this on eth1( 2.x) interface.

route add -net 0.0.0.0  netmask 0.0.0.0 gw 192.168.1.232

anything else to be needed for this thing to work?

Also i had enabled ip_forwarding

Thanks and Regards
Sakthish

=======              ======== 2.35         =======    
@ 1.x @______________@ Linux @_____________@ 2.x @
@     @        1.232 @  Box  @             @     @
=======              ========              =======

a better picture...Sorry in not good at drawing ...

Some better this would be..
1.x <----> 1.232 (Linux Box IPs) 2.35 <----> 2.x
                 

First of all it's important to reliaze that all nodes on a given network are always reachable by each other without routing. So, the Linux box can reach any node on the 192.168.1.0/24 network because it's first NIC is directly connected to that network. And the Linux box can reach any node on the 192.168.2.0/24 network because it is attached to the second NIC. In a like manner the router can see all of the nodes on the 1.0 network because it has an interface on that network.

Since IP Forwarding is enabled on the Linux box, it knows to forward a packet from the 2.x network that is destined to the 1.x network. It also has a default route pointing to the Cisco router so it also knows that packets destined for outside of the local lan need to be forwarded to the Cisco. Consider what happens when a node on the 2.x net sends something out to the Internet. Assuming the client has the correct default gateway set, namely 2.35, the packet will go to the Linux box which will forward it to the Cisco. All okay so far.

Now think about the return packet from the Internet. It gets to the Cisco and there's a problem. The router knows where the 1.x network is but it doesn't know where the 2.x network is. That's where the static route comes into play. The Cisco must have a static route that says that the 2.x network can be reached by sending packets destined for the 2.x network to 1.232. By the logic above, Linux, once it receives the packet forwarded by the router knows where the 2.x network is an it'll send the packet out its second NIC

Oh yes, since you are using an RFC 1918 private address scheme on you local network the Cisco also has to be told that both the 192.168.1.0/24 and 192.168.2.0/24 networks need to be NAT'd onto your outside IP address space.

thnx for the reply, but my concerns are

1. i cant able to ping from any of nodes in 2.x to any other hosts in 1.x, but i can ping 1.232 from any host in 2.x

2. the same thing happenes for the 1.x also. ie i can ping 2.35 from any host iin 1.x network and not anyother hosts in 2.x

as im going to use this setup internally i dont want the cisco to come into picture.

all i need is to access the hosts in both networks from both 1.x and 2.x networks using ip address.

once again thnx from the reply.
sakthish

just listening :)

thnx for u suggestions on this issue, i could able to sort out the problem. i would like to keep in touch with you. my eamil ID is sakthish@yahoo.com would like to know urs.

bye...u deserve these points fully cheers!!!