Grant Taylor schrieb:
> On 07/30/07 09:10, Ralf Gross wrote:
> >I'm trying to increase the bandwidth between two hosts (backup). Both
> >hosts are in the same /24 subnet and each of them is connected to a
> >Cisco switch by 2 GbE interfaces (intel e1000). The switches/host are
> >located in different building which are connected by 3 x GbE.
>
> Ok, this is simple enough.
>
> >My goal is to increase the bandwidth for a single tcp session between
> >the two hosts for a backup job (per packet round robin?), not for
> >multiple connections between many hosts. I know that I won't get 2 x
> >115Mb/s because of packet reordering, but 20-30% more that a single
> >connection would be ok.
>
> *nod*
>
> >Any ideas what I'm missing, or if it's possible at all?
>
> You are barking up the wrong tree, or at least the wrong layer. If you
> have any control of the switches in each building, or can have someone
> make changes to them for you. Bond the two connections together to make
> one logical larger connection. Cisco calls this "EtherChannel" and
> Linux calls this "Bonding".
I've tried bonding before. But this didn't work either because the
cisco switch decides on a src/dst mac/ip hash which port of the port
channel will be used. But in my case the hash is always the same
because between host A and host B. Thus always the same interface was
used.
> In the long run you will end up with two raw ethernet devices enslaved
> in to one bond0 interface. These two bonded / etherchannel interfaces
> will have very close to 2 Gbps worth of speed.
But not between host A and host B. I've gone through this a while ago,
everyone told me than that I've to solve the problem on L3 ;)
> Do this on the lower OSI Layer 2 rather than trying (and failing) to do
> it on the higher OSI Layer 3 where you are doing it presently.
I think it's not possible with the Cisco switches we use here to
increase the bandwidth between 2 hosts on L2.
Ralf
_______________________________________________
LARTC mailing list
LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
|