# LACP on FreeBSD



## donglee (Dec 30, 2013)

My FreeBSD server has two NIC cards. I want to know if I can enable LACP between the Cisco WS-C2960-24TC-L switch  and my FreeBSD server. You can see the datasheet of my switch, and I am sure it can support LACP. But I have no idea about FreeBSD.


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## wblock@ (Dec 30, 2013)

lagg(4) does LACP.


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## gpw928 (Jan 8, 2014)

Hi,

I run bonding between FreeBSD and Debian Linux systems. The combination of PCIe and Intel Ethernet cards gives some pretty impressive results.

You need to understand what your switch can do.  There are many variations on the theme.  But the basic ones use an xor of MAC addresses of the sending and receiving "hosts" to choose the wire on which to transmit a packet.  In short, you may never use more than the bandwidth of a single NIC between two given "hosts" (because the MAC addresses are generally fixed).  If this is a problem, there are ways around it (round-robin and Layer3+4 transmit policy) but you need to read the manuals.

This document https://www.kernel.org/doc/Documentation/networking/bonding.txt is Linux centric, but a very good general read on 802.3ad and LACP (especially chapter 12 for maximising bandwidth).

The Cisco manuals are generally available on-line (Cisco invented Layer3+4 transmit policy, and it violates the standard, but most implementations support it).

Cheers,


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## SirDice (Jan 8, 2014)

Look at example 30.1 in the handbook: http://www.freebsd.org/doc/en_US.ISO885 ... tion-cisco


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