[114113] in North American Network Operators' Group
RE: 10-GigE for servers
daemon@ATHENA.MIT.EDU (Matthew Huff)
Fri May 1 14:27:20 2009
From: Matthew Huff <mhuff@ox.com>
To: 'Chris Adams' <cmadams@hiwaay.net>, "'nanog@nanog.org'" <nanog@nanog.org>
Date: Fri, 1 May 2009 14:27:02 -0400
In-Reply-To: <20090501181558.GB911164@hiwaay.net>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
It's also host dependent. The switch will hash based on the algorithms it s=
upports, however it can be asymmetrical if the host doesn't support the sam=
e ones. Most host OS's don't hash outbound to the switch based on layer 4 o=
r above. Most only hash at layer 2.
There are 10GE cards for most hardware and OS platforms. Getting them to ru=
n at a fraction of that speed depends on application and IP stack tuning. E=
ven then, there are significant bottlenecks. That's one reason Infiniband f=
or HPC has taken off.
----
Matthew Huff | One Manhattanville Rd
OTA Management LLC | Purchase, NY 10577
http://www.ox.com | Phone: 914-460-4039
aim: matthewbhuff | Fax: 914-460-4139
> -----Original Message-----
> From: Chris Adams [mailto:cmadams@hiwaay.net]
> Sent: Friday, May 01, 2009 2:16 PM
> To: nanog@nanog.org
> Subject: Re: 10-GigE for servers
>
> Once upon a time, Alex Thurlow <alex@blastro.com> said:
> > As long as it's not a single connection that you're looking to get
> over
> > 1Gb, etherchannel should actually work. It uses a hash based on (I
> > believe) source and destination IP and port, so it should roughly
> > balance connections between the servers.
>
> That depends on the devices on each end. For example, some switches
> can
> only hash on MAC addresses, some can look at IPs, and some can look at
> ports.
>
> --
> Chris Adams <cmadams@hiwaay.net>
> Systems and Network Administrator - HiWAAY Internet Services
> I don't speak for anybody but myself - that's enough trouble.
