[114452] in North American Network Operators' Group
Re: two interfaces one subnet
daemon@ATHENA.MIT.EDU (David Devereaux-Weber)
Mon May 11 18:18:59 2009
In-Reply-To: <c7ef7cf70905111428k2167098es98b1272387f830c7@mail.gmail.com>
Date: Mon, 11 May 2009 17:08:45 -0500
From: David Devereaux-Weber <ddevereauxweber@gmail.com>
To: Hector Herrera <hectorherrera@gmail.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
In my case, each Ethernet interface has its own unique MAC address.
Dave
On Mon, May 11, 2009 at 4:28 PM, Hector Herrera <hectorherrera@gmail.com>wrote:
> On Mon, May 11, 2009 at 2:22 PM, David Devereaux-Weber
> <ddevereauxweber@gmail.com> wrote:
> > Chris,
> >
> > I work with iHDTV <http://ihdtv.org>, a project that sends uncompressed
> high
> > definition television (1.5 Gbps) as UDP over two 1 Gbps interfaces. If
> both
> > interfaces are on the same subnet, the OS sees the same router (gateway)
> > address on both interfaces, and the results are sub-optimal ... around
> 50%
> > packet loss.
>
> packet loss is probably due to the network switch having to re-learn
> the location of the MAC address constantly as it sees packets on two
> or more ports with the same MAC address (think STP loops).
>
> If your network stack and network device (switch) supports LACP, then
> you can have multiple connections between a host and a network device.
> That is a very easy way to increase capacity and add redundancy.
>
> That is how all of our VMWare ESX 3.5i servers are connected.
>
> Hector
>
