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@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
