should if_lagg balance outbound traffic on an lacp connection ?

[Pete French]

Having recently discovered if_lagg in stable I have spent the last couple
of days experimentsin with this and using it to aggregate connections between
a pair of servers and a pair of Cisco switches. It all appears to be
functioning, but looking at the stats I see this:

Name    Mtu Network       Address              Ipkts Ierrs    Opkts Oerrs  Coll
bce0   1500 <Link#1>      00:19:bb:33:00:de  7545268     0  9303330     0     0
bce1   1500 <Link#2>      00:19:bb:33:00:de  7099168     0      126     0     0
lo0   16384 <Link#3>                           15377     0    15376     0     0
lo0   16384 fe80:3::1     fe80:3::1                0     -        0     -     -
lo0   16384 localhost     ::1                     60     -       60     -     -
lo0   16384 your-net      localhost            14222     -    14221     -     -
lagg0  1500 <Link#4>      00:19:bb:33:00:de  7545187     0  9303208    58     0
lagg0  1500 10.17.16/20   turpentine         7539218     -  9305974     -     -

Note that whilst I am getting evenly split traffic comming in from the switch,
outgoing traffic is all heading out on bce0. The ifconfig output looks
like this:

        options=3b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU>
        ether 00:19:bb:33:00:de
        media: Ethernet autoselect (1000baseTX <full-duplex>)
        status: active
        lagg: laggdev lagg0
bce1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=3b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU>
        ether 00:19:bb:33:00:de
        media: Ethernet autoselect (1000baseTX <full-duplex>)
        status: active
        lagg: laggdev lagg0
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3 
        inet6 ::1 prefixlen 128 
        inet 127.0.0.1 netmask 0xff000000 
lagg0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        inet 10.17.19.0 netmask 0xfffff000 broadcast 10.17.31.255
        ether 00:19:bb:33:00:de
        media: Ethernet autoselect
        status: active
        lagg: laggproto lacp
                laggport bce1 =18<COLLECTING,DISTRIBUTING>
                laggport bce0 =1c<ACTIVE,COLLECTING,DISTRIBUTING>

On the switch both ports are configured in LACP 'active' mode. Is this
expected behaviour, or have I done something wrong ? My rc.conf file looks
like this:

cloned_interfaces="lagg0"
network_interfaces="lo0 bce0 bce1 lagg0"
ifconfig_bce0="up"
ifconfig_bce1="up"
ifconfig_lagg0="laggproto lacp laggport bce0 laggport bce1"
ipv4_addrs_lagg0="10.17.19.0/20"


Any advice ? Or that simply the expected behaviour ? (I dont actuall mind
if it is - I am aiming for fault tolerance not performance on this
connection, but I am curious for future reference)

cheers,

-pcf.