Yes this is the correct diagra.
Mean while I have agian posted my question with the diagram fixed. Please ignore it.
Got your point Martin about why its not working. I will try it later again.
I apologise for posting the wrong question.. and thank once again to Martin for taking the pains to correct the diagram and sending and answer. I was in a fix and didnt knew where to send the question. I paniced.. sorry..
I will take care of this in future.. Thanks Dp
Martin A. Brown wrote:
Dhirendra,
: Dsl feed goes to gateway 1. Its internal ip address is of 192.168.1.XXX. : Now from here goes the feed to another gateway which eth0 ip address is : 192,168.1.50. It has 2 more eth - eth1 and eth2. Their ip address are : 192.168.2.51 and 192.168.3.XXX respectively. : Now my problem is that all the computers connect to 192.168.2.XXX are : unable to point to the computers of 192.168.1.XXX. Though strangely I : can ping to 192.168.1.1 wich is the internal ip address of the gateway 1.
Is this your network, or did I mangle it in reconstruction?
eth0 192.168.1.50 \ |----------| |----------| | gateway 1|-------------------------| gateway2 | /|__________|\ | |----------| / \ | / \ eth0 eth1 | / \ 61.X.X.X 192.168.1.1 | eth1 eth2 (public) | 192.168.2.51 192.168.3.52 | | ------------ | | BOX 1 | ------------- ------------ | Box 3 | 192.168.1.101 ------------- 192.168.3.101
You can ping 192.168.1.1 because it is a locally hosted IP on the default gateway of the machines in the 192.168.2.0/24 network.
: I have the following setup on redhat linux 8.0 ... : : A) I am unable to ping from Box 3 (192.168.3.101) to Box 1. Any : comments or reasons why?
It looks like you have a common routing problem. If you examine the routing tables on gateway 1 and box 1, they are probably missing routes to 192.168.3.0/24 and 192.168.2.0/24 via 192.168.1.50. Host 1 probably has a default route to 192.168.1.1 and gateway 1 certainly doesn't have a default route pointing *into* your network.
<gripe> This is not really a LAR (and certainly not a TC) question. This is a basic routing question. Let's try to keep these questions off the LARTC list....this is probably better for a forum like comp.os.linux.networking or a LUG. </gripe>
<helpful-hat> You may find some of my documentation useful in conceptualizing static routing:
http://linux-ip.net/ http://linux-ip.net/html/ch-routing.html
For others who are following along with questions like this, I would recommend using a network analyzer of some kind to look at the packets on each of the machines involved.
- use tcpdump or ethereal on each affected router and end-host - generate regular traffic (ping, nc, socat, etc.) while trying to determine where the packets are getting dropped or misrouted </helpful-hat>
So, Dhirendra:
Remove the masquerading from gateway2
[root@xxxx]# ip route add 192.168.3.0/24 via 192.168.1.50 [root@xxxx]# ip route add 192.168.2.0/24 via 192.168.1.50 [user@xxxx]$ ping -n 192.168.1.101
You should get a response.
[root@xxxx]# ip route add 192.168.3.0/24 via 192.168.1.50 [root@xxxx]# ip route add 192.168.2.0/24 via 192.168.1.50
: B) I have figured out that if I enable Masquerading then problem A is : solved. Can someone explain why?
Because you are changing the source IP on the packets to a 192.168.1.0/24. When you do this, the other hosts in 192.168.1.0/24 have a direct route for reply packets.
: C) Is it possible without Masquerading ?
Yes.
-Martin
Anybody think a LARTC FAQ is a good idea?
