Solaris Link Aggregation

Setting up link aggregation in Solaris is pretty simple. First make sure you have a recent version (I'm using update 5 aka 5/08 and update 6 aka 10/08).

Then make sure your switch is configured. For example, on one of my Summit switches where I'm going to aggregate ports 7 and 8:

enable sharing 7 grouping 7 8 lacp

You can see the state of the network interfaces on the host using dladm, for example:

# dladm show-dev
nxge0           link: up        speed: 1000  Mbps       duplex: full
nxge1           link: up        speed: 1000  Mbps       duplex: full
nxge2           link: unknown   speed: 0     Mbps       duplex: unknown
nxge3           link: unknown   speed: 0     Mbps       duplex: unknown

Then on the host (connected to the console - trying to do this over the network is obviously going to be difficult), take down the existing interface:

ifconfig nxge0 down unplumb

Create an aggregate out of nxge0 and nxge1, with index 1 (why normal interfaces start out with index 0 and aggregations start out at 1 is one of those oddities):

dladm create-aggr -P L2 -l passive -d nxge0 -d nxge1 1

And then bring the interface up:

ifconfig aggr1 plumb
ifconfig aggr1 inet 172.18.1.1 netmask 255.255.255.0 broadcast 172.18.1.255 up

and then rename /etc/hostname.nxge0 to /etc/hostname.aggr1 so the right thing happens next boot.

Here I've enabled LACP (the '-l passive' flag). I'm not absolutely sure how vital this is, but I think the switch and the host need to be set compatibly.

I had a little play with the policy. In the command above it's set to 'L2'. This didn't work well for me - all the traffic went down one of the links. Same with 'L3'. Setting to to use both L2 and L3 seemed to work better

dladm modify-aggr -P L2,L3 1

and I got traffic using both links, and an aggregate throughput obviously in excess of a single gigabit.

Monitoring the aggregate can again be done using dladm. For example, you can watch the traffic and how much goes down each link with 'dladm show-aggr -s -i 1'.