Adrian
Contributor
- Joined
 - Jun 29, 2011
 
- Messages
 - 166
 
I have been bitten by this on 2 of my 3 dual NIC machines.
On a reboot a lagg interface may change which interface is the master.
If you are using DHCP it is wise to ensure that all the physical interface MAC address are given the same static DHCP IP address and host name, otherwise the lagg may gain an unexpected IP address, casing confusion and woe.
In this example of a flipped and fixed lagg, igb0 in under 11.2-U7 and previous igb0 had always been the master. I have not yet noticed a lagg flipping back.
	
		
			
		
		
	
			
			On a reboot a lagg interface may change which interface is the master.
If you are using DHCP it is wise to ensure that all the physical interface MAC address are given the same static DHCP IP address and host name, otherwise the lagg may gain an unexpected IP address, casing confusion and woe.
In this example of a flipped and fixed lagg, igb0 in under 11.2-U7 and previous igb0 had always been the master. I have not yet noticed a lagg flipping back.
Code:
igb0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        description: member of lagg0
        options=6403bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6>
        ether d0:50:99:c2:35:ec
        hwaddr d0:50:99:c2:35:eb
        nd6 options=9<PERFORMNUD,IFDISABLED>
        media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
igb1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        description: member of lagg0
        options=6403bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6>
        ether d0:50:99:c2:35:ec
        hwaddr d0:50:99:c2:35:ec
        nd6 options=9<PERFORMNUD,IFDISABLED>
        media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
        options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
        inet6 ::1 prefixlen 128
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3
        inet 127.0.0.1 netmask 0xff000000
        nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
        groups: lo
lagg0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        description: lagg0
        options=6403bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6>
        ether d0:50:99:c2:35:ec
        inet 192.168.1.50 netmask 0xffffff00 broadcast 192.168.1.255
        nd6 options=9<PERFORMNUD,IFDISABLED>
        media: Ethernet autoselect
        status: active
        groups: lagg
        laggproto failover lagghash l2,l3,l4
        laggport: igb0 flags=0<>
        laggport: igb1 flags=5<MASTER,ACTIVE>