Page 1 of 1

HELP!! GIT 0.99b4 + MS Loopback adapter scenario fails

PostPosted: Fri Nov 18, 2005 5:35 pm
by hckRoBiN
Hi all,

Here is the scenario (this is a test setup to figure out what's wrong)

I have 2 computers directly connected via ethernet.

PC1: IP: 10.0.0.1 / 255.255.255.0
PC2: IP: 10.0.0.12 / 255.255.255.0

They see each other perfectly, there is no firewall turned on.

Both machines also have a MS Loopback interface configured,
PC1 has 192.168.0.1 / 255.255.255.0
PC2 has 192.168.0.2 / 255.255.255.0

What I want to achieve is to have the 2 loopback device see each other
as if they were real cards connected.

So, I installed Git0.94b4 on both machines, and configured it
to "forward arp, ethernet II, ieee802.2, tcp, udp, icmp, also
match source port" in advanced config, sniffing on the loopback device.

I configured tcp connect on PC1 (port 213) to 10.0.0.1
and I configured PC2 to tcp listen (port 213) from 10.0.0.12

After that, the connection state was "UP"

I tried to ping 192.168.0.1 from the machine that has the other IP (192.168.0.2) and vice versa, but both failed.

I tried packet capturing with ethereal on both machines to monitor the loopback devices. It seems to me that the problem is that the ARP
request (whois) is forwarded from the "pinger" machine to the other,
and the ARP reply is even on the wire on the "pinged" site, but the ARP
reply doesn't get forwarded back to the first computer, so
the real ICMP ping package is never sent.

(When pinging in the other direction also only the first ARP request
gets through to one direction...)

What am I doing wrong?
Is this really a configuration error?
What more info do you need to help me? :)
What did I miss in the earlier posts? :)

PostPosted: Mon Nov 21, 2005 4:51 pm
by hckRoBiN
Okay, finally I found it myself.
First I have to specify unique MAC addresses to the loopback interfaces.
After that it seems to work. (Although problems occur with large traffic,
for example an ftp transfer on the virtual lan)