10-GigE for servers

Fri May 1 18:27:02 UTC 2009

It's also host dependent. The switch will hash based on the algorithms it supports, however it can be asymmetrical if the host doesn't support the same ones. Most host OS's don't hash outbound to the switch based on layer 4 or above. Most only hash at layer 2.

There are 10GE cards for most hardware and OS platforms. Getting them to run at a fraction of that speed depends on application and IP stack tuning. Even then, there are significant bottlenecks. That's one reason Infiniband for HPC has taken off.

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> -----Original Message-----
> From: Chris Adams [mailto:cmadams at hiwaay.net]
> Sent: Friday, May 01, 2009 2:16 PM
> To: nanog at nanog.org
> Subject: Re: 10-GigE for servers
>
> Once upon a time, Alex Thurlow <alex at 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 at hiwaay.net>
> Systems and Network Administrator - HiWAAY Internet Services
> I don't speak for anybody but myself - that's enough trouble.