I am currently using Cisco 3750E StackWise+ Switches. However, it seems that this type of switch only supports layer 2 (MAC address - src/dest/src and dest) and layer 3 (IP address- src/dest/src and dest) hashing possibilities concerning EtherChannel load balancing. Is there an (affordable compared to the 3750E) switch available which supports layer 4 (TCP port - src/dest/src and dest) etherchannel load balancing?
4500 series minimum. Thats certainly more expensive the the 3700 series.
formatting link
Is there a reason you specifically need layer 4? Only reason I really see is for it is multiple services on a server that are max'ing out, i.e email and web on a single server with email taking 100% of the bandwidth. If thats the case, it's cheaper just to add more servers and break out the services on to individual servers.
Well let me explain the background of this question:
Server A (TSM client) needs to backup to Server B (TSM server) over Ethernet. Server A can have multiple TSM sessions to server B, resulting in multiple tape mounts. Furthermore each TSM session corresponds to one TCP session. Server A and Server B both have a layer 4 EtherChannel defined of 4 interfaces in which the hashing is based on source and destination ports. So this means that, whenever Server A starts 2 TSM sessions to Server B (= 2 TCP sessions resulting in 2 tape mounts), the EtherChannel on server A will balance the load on two switchports (given the used hashing algorithm). Unfortunately, since my 3750E only allows layer 2 and layer 3 EtherChannel load balancing, all load will be placed on the same physical port of server B's EtherChannel, only resulting in a maximum throughput of only 1 Gbit/s for server A. Ofcourse, whenever another server (f.e. server C) starts a TCP session with server B, it is likely (75% chance) that it will use another port of Server B's EtherChannel... Bottom line is that Server A will never get a bandwidth higher than 1 Gbit/s no matter how many TCP sessions is starts with Server B.
I don't know of any switch that supports the type of EtherChanneling you need. How about installing 10Gb/s cards in the two servers and connecting them back to back?
If I look at the 4500 series, it is capable of examining the TCP traffic and do load balancing based on src/destination TCP ports. However, as already stated, this is an expensive solution and I think I will look after something else. Unfortunatele, the 10 Gbps ports are already used for uplinks.
Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.