Layer-4 Load Balancing

[tantra35]

Hi

Does FreeBSD have software to support "Layer-4 Load Balancing" like LVS? I found only ipvs, but it doesn't work on FreeBSD 8.0.

 

[SirDice]

As I understood it the balancing is done on layer 7, not 4.

Have a look at net/haproxy.

 

[tantra35]

No its l4 router.

http://www.linuxvirtualserver.org/VS-DRouting.html

For example it's allow balance outgoing traffic

 

[SirDice]

If you want layer3/4 load balancing have a look at CARP.

 

[phoenix]

Or lagg(4), or setfib() combined with ipfw(8) rules.

 

[Galactic_Dominator]

Neither lagg, nor carp offer L4 load balancing. They use L2 and/or L3.

 

[mamalos]

Pardon my ignorance:

Which is the 4th layer in the TCP/IP stack? Because layer 7 filtering refers to OSI layer 7, and as far as I knew (until now) TCP/IP's layer 4 was equivalent to OSI's 7th layer (since IP does not implement all 7 OSI layers).

Of course I may be totally wrong, but since I see that some of you know, please post a reference to layer 4 filtering in IP networks.

 

[Galactic_Dominator]

Which is the 4th layer in the TCP/IP stack?

TCP(or any other protocol immediately following the layer 3 IP)

• Layer 2 LB is done on the destination MAC
• Layer 3 LB is done on the destination IP
• Layer 4 LB is done on the combination of destination IP address and port.
• Layer 5 LB is done on the combination of destination IP address, port and protocol eg http connection.
• Layer 7 LB is done at the application level eg cookie.

I don't know of any serious modern discussions on alternatives to the OSI model. It won. Unless otherwise specified, it should be assumed the default without question.

 

[mamalos]

Galactic_Dominator,

do you have a reference (citation) of the layers you're mentioning? Stevens, in "TCP/IP illustrated vol. 1", p.6 shows 4 protocols (but refers to an additional one), which are stacked like this:

• application layer (user process)
• transport layer (TCP/UDP)
• network layer (ICMP/IP/IGMP)
• link layer (ARP/Hardware Interface/ RARP)
• media

Of course, your answer refers to load balancing layers, which might be different than network stack layers, since in network terminology when someone refers to a layer-x program, it usually means that the program is handling information exchanged only from the x-th layer (and not a combination of all preceding protocols).

Nevertheless, I can see your point, so maybe there is no need for an answer in my post.

Thanks for your answers.