[mpls-linux-general] Problems with ethernet cards

[Daniel G. C. <da...@on...>]

Hi!I'm making a network with some Pcs with MPLS-Linux installed over
Red Hat 7.1.
Now, I'm connecting the PCs directly with cross-connect cables and I
have some problems.
I am trying to connect 3 Pcs in this way 1--2--3, the first PC have a
Realtek and
a 3Com card but I use the Realtek to connect to the second PC, the second PC
have
two ethernet cards, one Realtek RTL 8139(A) and one 3Com 3c509 Tornado
series, and the third PC have two 3Com cards and a Realtek one
but I use one of the 3Com cards to connect to the second PC.

This is:

1 (Realtek) <--> (Realtek) 2 (3Com) <--> (3Com) 3

Before I try to use mplsadm to configure the MPLS network, I am trying
to test the connections making ping between them, but when I try it,
it only work in one way, for example between 2 and 3 or between 1 and
2. And when I deactivate the card that seems that doesn't work in 2,
and then when I reactivate it, it begins to work in the other way but it
doesn't work in the first way that was working before.

It is:

   if the Realtek cards work in 2 <--> 1
       I deactivate the Realtek (in 2) that works 2 <--> 1
       I reactivate it
       now, the 3Com works in 2 <--> 3
       but the Realtek doesn't works in 2 <--> 1

   else
        if the 3Com cards work in 2 <--> 3
           I deactivate the 3Com (in 2) that works 2 <--> 3
           I reactivate it
           now, the Realtek works in 2 <--> 1
           but the 3Com doesn't works in 2 <--> 3

(To activate and deactivate the cards I use the ifconfig command or
the 'network configuration' utilitie that is in the 'System' menu on
Gnome X-window system)
(I am using IP addresses that belongs to the same network for all the
cards, but I don't think this is a problem because I am doing a ping between
two PCs that are directly connected.)

I don't know what it happens, if somebody have seen it before and
know how to fix it, please help me!

And I don't know if it would make problems when I try to configure
the MPLS network with mplsadm, I supose that if I can't ping in one
way, MPLS wouldn't work in this way. Please, help me I don't know what to do
so I
would be very pleased if someone can help me.

Best regards.

Dani