Take the 2-minute tour ×
Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Is it possible to multiplex two (or more) 1Gbps Ethernet into a single logical connection? Is it common place? Advisable? Stupid? Other considerations?

I ask because my hosting partner's network infrastructure is 1Gbps, but I have the need for more. 10Gbps networking kit is still on the pricey side, especially in the context of a high-availability Internet-facing data center. So, I'm exploring other options.

share|improve this question
5  
As many have indicated, teaming (LACP) is the common method. One thing to clarify though is that the method of teaming (MAC/IP addresses, etc) can limit the throughput of an individual connection to 1Gbps. For example, if you are teaming NICs on a server and mounting drives from an iSCSI target, you will only get 1Gbps to that server because the team will use the IP address combination to determine the path. There are round-robin schemes, but both sides of the connection have to support it. This "feature" of LACP can often trip you up the first time you use it. –  Kevin Kuphal Jul 14 '09 at 21:22
2  
@Kevin Kuphal: Thanks for this tip. The problem is actually easier to run into than I had imagined: We ran into the 'single path' problem with an HP ProCurve 2510G-24, which does its hash based on source & destinations MAC addresses--and no IP in the mix. That ment our properly LACP'd Linux server (distributing Tx packets over all links) faced a bottle neck getting off the switch and to the GW. Bonded ports apparently present only on MAC address! –  Stu Thompson Aug 16 '10 at 15:25

3 Answers 3

up vote 10 down vote accepted

Yes, it's called a variety of things such as 'teaming', 'etherchannel', 'DMP', 'MPIO', 'bonding' etc. but it happens all the time and is supported by most modern operating systems straight out of the box.

It's a very advisable thing to do if you have the spare ports on the server/pc and the switch - firstly because it allows you machine to carry on if a port or cable breaks and secondly because they can in many circumstances aggregate your traffic down both links to effectively give you 2Gbps.

Feel free to ask any more detailed questions around this area.

share|improve this answer
    
Thanks! Failures: I'd probably go with an additional 4-port NIC in the servers. We also have a hot standby fail over server. MORE: I need to know more about the network infrastructure issues...between my server, through the switch, through the packet filter and onto the Internet. (Time to go research those new terms! Thanks again.) –  Stu Thompson May 15 '09 at 7:52
    
Oh it's worth knowing that often you can use more than two ports if needed, although I've personally never seen more than 4 links being used at once. –  Chopper3 May 15 '09 at 7:59
    
So, it's taken a bloody year but I'm going forward with this at a new colo providing a 2Gbps LACP link. We'll be moving upwards to 4x as needed. Thanks again. –  Stu Thompson Apr 26 '10 at 9:39

Switches usually support some (~64) aggregated links with up to 8 ports each. But before adding a Quad-NIC to a single server you should think putting about a load balancer with 4 GigE ports in front of your servers.

When using LACP, it's important to know which load balancing algorithm is used by the trunk. Normally you can (and should) choose between MAC- and/or IP-addresses and/or TCP/UDP-Ports as a source for load balancing.

Failover is really fast with LACP, you lose just a little more than the packets on the wire.

share|improve this answer
    
Clarification: I've two servers, 'live' and 'hot standby'. I need the multiple GigE on the individual servers. –  Stu Thompson Jul 15 '09 at 8:00

So-called 'smart switches' employ a thing called Link Aggregation Control Protocol which allows you to bundle multiple ports together and use them as if they were one wide link... I'm not completely clear as to your precise need, but this maybe another term worth researching.

share|improve this answer
    
"Precise need"? I need a >1Gbps connection to the Internet for my Server, but find 10Gbps network infrastructure pricey. –  Stu Thompson May 15 '09 at 9:55
    
"A single logical connection" to where, exactly? Your colo's gateway? Another colo's gateway? Please forgive me for trying to help... –  avstrallen May 15 '09 at 10:39
1  
@adamvs - I think what Stu is saying is that his hosting provider wants y for gigabit and 10 time y for 10G. I think Stu wants to know if he can buy 2 1Gb ports and team them together. –  Aaron May 15 '09 at 14:30

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.