Defualt gateway vs Interface Lan Card

[Abdul Majeed Lardhi]

Dears,
I have to lan cards lan0,lan1(two IP configured) in the same subnet which menas I have only one default gateway !!!

before I reboot the default gateway (UG)interface was pointing to lan0, when I reboot the server I found ( netstat -rn) that the default gateway (UG) pointing to inerface lan1 !!!!

How I change it back to lan0 ????
and why it does happen ??

Regards
Abdul Majeed

[Ron Kinner · Accepted solution]

The configuration you have with two NICs on the same subnet is not supported in HPUX so there is no mechanism to tell it which LAN card to use. I suppose if you delayed activating the second LAN card for a while during boot the software would always choose the active card.

I expect if you unplug the lan1 card (or disable it) for a few minutes that it would start using the other one.

Ron

[Victor Fridyev]

Hi,

The configuration when two lan cards are configured in one subnet is illegal.
You have to update your network configuration accordingly.

Sorry.

HTH

[Florian Heigl (new acc)]

For now You should disable one of the two interfaces and re-set the default gateway to Your the system in a more sane configuration. (not messing up the routing, that is)

For later, look into HP's port aggregation product and see if Your switch will play nice with it. (that will give You a virtual lan card with the two real interfaces beneath; advantages are real load-balancing and redundancy)

[Abdul Majeed Lardhi]

becuase I just want to simplify,
I forgot to mention that the lan0 and lan1 is a ports aggregation, actually lan0 is 4 lan cards and lan1 is 2 lan cards
!!!

Is any option to change without effect the network conection for example using lanadmin


Cheers

[Ivajlo Yanakiev]

You can change your default route using
route delete
route add

You no need to reboot server

[Abdul Majeed Lardhi]

Sorry but my question not to change the deafult routeing !!!

my question how to point the default route (gateway) to one of the interface ???

cheers

[rick jones]

if you have actually put the physical interfaces behind lan0 and lan1 into an aggregate, it would be accessed via lanNNN where NNN is some much larger number. And ifyou have put them into an APA aggregate, you must use _that_ interface name and not lan0 and lan1 anylonger.

Indeed, it is best that (as far as the transport is concerned) distinct physical interfaces have addresses in distinct IP subnets. However, if your router(s) support proxy arp you could use one of your two local IP addresses as the default route (with a metric of zero) and thus specify it specifically