How to oblige the IP traffic to use one lan card

[Enrico Venturi]

Hi all,
the problem is very hard!
My application runs on a HP Server with 2 lan cards, namely lan0 and lan2.
Both have their IP addresses, IP0 and IP2.
The application uses a proprietary OSI stack running on lan2 to talk with an external OS; inside the application there's a subsystem which uses the IP to talk with a subsystem inside the external OS which uses IP; because this IP traffic is sent over OSI the supposed used lan card is lan2, so the application ask the remote OS to accept messages coming from IP2 (the lan2 IP); actually the used lan card is lan0, and the source IP is IP0; this produces a mismatch between the enabled source IP and the actual source IP. Now, my question is: even if two lan cards can be used to reach a remote IP, can I oblige the system to use one of them?
Thanks a lot
Enrico

[U.SivaKumar_2]

Hi,
Are the Lan cards connected to same network ?.
Or do you have another gateway (router) to connect these cards ?.
IF possible , please attach a rough sketch of your setup.
Also check with that application people that can we bind that application to any one of he
interface as we usually do in samba , bind .etc

regards,
U.SivaKumar

[Steven Sim Kok Leong]

Hi,

Use the routing table to send outbound traffic through specific interfaces.

You can hardcode the routes (the interface bound for each route is also specified) in /etc/rc.config.d/netconf.

Following command shows the interface used for routing traffic to the network of your destination.

# netstat -rn

Hope this helps. Regards.

Steven Sim Kok Leong

[Domenico_5]

Ciao Enrico

Which OS areyou using?
11i?
Un this Os two ip on the same network are not supported.

However I had a problem like yours with ftp service and I have solved it configurig a fw correctly.

So which application doesn't work?

[Enrico Venturi]

Thanks for your quick replies!
The application is a proprietary one.
We have one Operational System (OS) managing one Network Element (NE) with an ISA board .
The Operational System (OS) talks in OSI with the NE, but one OS subsystem talks in IP with the ISA board inside OS.
The operating system is HP-UX 11.
HP-UX 11 doesn't allow two IP addresses in the same network (i.e. 151.98.xxx.yyy) but it allows two or more IP in differen t networks.

The lan cards are connected to the same HUB (so, to the same gateway). Actually this is a useless configuration in this case, but we have the target to manage the NE network by the lan card 2 and to talk with the other OS by the lan card 0, which are usually on different networks.

[sven verhaegen · Accepted solution]

the answer is yes... depending on your setup :

.by creating a routing entry using the route add command and setting it to the right network you can force it to use a specific interface , some things need to be taken into account :

- the 2 lancards you are talking about "SHOULD NOT BE IN THE SAME NETWORK IP RANGE" as HP doesn't support this

- further if in the routing table there are 2 possible ways of reaching a remote network priority will go the the first route encountered even if in fact you have a default gateway or a secondary way working with a different count

. you could also activate the gated deamon on the HP-UX system and run RIP or OSPF dynamic routing protocols , that way you could start giving your interfaces weight and differtentiate the traffic accordingly

all depends on your initial lancard definitions , if you have further questions let us know