Re: Programming Interface to change routing table entries
From: Simon Marchese (sjm_news_at_yahoo.co.uk)
Date: Tue, 12 Jul 2005 23:18:10 +0000 (UTC)
> I have a program running on AIX 5.2 and I need to disable the Multipath
> routing feature. As per my understanding, if I have 2 NICs, then due to
> Multipath routing, when the OS sends packets out, it does a round robin
> scheduling of the packets between the 2 NICs. Is there a way to disable
> this feature? I want to be able to decide which NIC to use when sending
> the packets out without detaching or bringing down any interface. Can
> this be done programatically?
> One way I thought of was to remove the entries of an interface from the
> routing table. I tried doing this using route delete and it works. But
> I need to do this in a C program. Can someone please help me with the
> APIs or ioctls I need to use to do this?
If they're two NICs on the same subnet, then no, multipath cannot be
turned off. And if they're on different subnets, then multipath does not
There is one sort of exception to this ... if you have created a
one-adapter etherchannel with a backup adapter, then only one is used at
any given time. You still can't change this programmatically, but it is
an exception to the above.