How to configure static route to individual LAN port

[Chew Kok Seng]

Hi,

Say I have 3 ip addresses:
172.16.9.60 on lan1
172.16.9.61 on lan2
172.16.9.62 on lan0
using a single gateway 172.16.9.1

My applications need to be routed such a way that application 1 uses only lan1, application 2 uses on lan2 and lan0 is use as management lan.

If I configure default routing on lan0 to the gateway, I see all my traffic being routed via Lan0 only. lan1 and lan2 are not used.

How can I configure such that the ip traffic destined for the ip addresses of lan1 and lan2 to use its on port and not using the default route/gateway?

[Ivan Krastev]

Configure it in netconf - see this thread http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=998591

regards,
ivan

[Chew Kok Seng]

the thread showed ip addresses on different subnets:
Head office Router.. 89.0.3.249
Router at DR Site... 89.0.2.249

But I have all addresses in the same subnet.
If I have to route message from:
172.16.9.60 to 172.16.9.12 for application 1
172.16.9.61 to 172.16.9.12 for application 2
Nothing to be sent via 172.16.9.62.

Will configuring net work for this case?

[Matti_Kurkela · Accepted solution]

It is very difficult to make this kind of configuration to work as you require.

Please see this thread:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=616802

You'll need to have the applications bind to their specific IP addresses, and enable the "Strong ES model" function:
ndd -set /dev/tcp ip_strong_es_model 1

According to HP-UX LAN Administrator's Guide, you should not enable two network interfaces of the same host into the same network segment at the same time.
http://docs.hp.com/en/B2355-90796/ch04s02.html
So, you're attempting an unsupported configuration and problems are likely.

By using the optional APA software, you can make several interfaces work like a single, higher-capacity interface and thus work around this problem somewhat. But it seems to me APA would not help you, as your needs are more complex than that.

[Chew Kok Seng]

Ok, now if I split the IP address to the two subnets
172.16.9.0/25 gw 172.16.6.1
172.16.9.128/25 gw 172.16.6.129

using ip address:
172.16.6.61
172.16.6.200

Can I do this?

ROUTE_DESTINATION[1]="net 172.16.9.0"
ROUTE_MASK[1]=255.255.0.0
ROUTE_GATEWAY[1]=122.16.9.1
ROUTE_COUNT[1]=1
ROUTE_ARGS[1]=""


ROUTE_DESTINATION[2]="net 172.16.9.128"
ROUTE_MASK[2]=255.255.0.0
ROUTE_GATEWAY[2]=172.16.9.129
ROUTE_COUNT[2]=1
ROUTE_ARGS[2]=""

With this allow the right messages to go to the right lan port?

[Matti_Kurkela]

That looks do-able, but at least one of your ROUTE_MASKs should be /25 (i.e. 255.255.255.128) too.

Routing decisions are made using binary AND operations as follows:

if ( AND ) = ( AND )
then send to

The routing table is automatically arranged so that the most specific routes are tested first. If nothing else matches, we get to the default route: it has a mask of 0.0.0.0, which means it will always match.

If you don't change your ROUTE_MASKs, your two route definitions will both match to all packets going to 172.16.*.*, which is not what you want.


ROUTE_DESTINATION[1]="net 172.16.9.0"
ROUTE_MASK[1]=255.255.0.0
ROUTE_GATEWAY[1]=172.16.9.1 #typo fixed?
ROUTE_COUNT[1]=1
ROUTE_ARGS[1]=""


ROUTE_DESTINATION[2]="net 172.16.9.128"
ROUTE_MASK[2]=255.255.255.128 # changed
ROUTE_GATEWAY[2]=172.16.9.129
ROUTE_COUNT[2]=1
ROUTE_ARGS[2]=""

If your default route still goes to 172.16.9.1, the first group is redundant.
The second group is the essential one to make the new subnet work.

[Chew Kok Seng]

Cool, it worked. thanks alot for the pointers.

[Chew Kok Seng]

A solution and explanation was found.