Bond not failing even when links are down

Hi,

I recently got 2 RB450’s as edge routers for a small web farm installation. Each router has 1 external interface and the 4 remaining ports are setup as 2 different internal networks. of 2 bonds of 2 ports each.

Whilst testing vrrp failover yesterday (which seems very fragile, but another post for those issues!) I noticed that when pulling the cables on the bonded NIC’s the bond remained active and running. Strangely, when 1 cable was pulled this sometimes triggered a vrrp failover (but not always) even though the bond status was running.

The RB450’s are running v5.18

Here’s the bonding information

 /interface bonding print
Flags: X - disabled, R - running
 0  R name="bond-a" mtu=1500 mac-address=00:0C:42:BD:19:39 arp=enabled
      slaves=a-e4,a-e5 mode=balance-alb primary=none link-monitoring=mii-type1
      arp-interval=100ms arp-ip-targets="" mii-interval=100ms down-delay=0ms
      up-delay=0ms lacp-rate=30secs transmit-hash-policy=layer-2

 1  R name="bond-b" mtu=1500 mac-address=00:0C:42:BD:19:36 arp=enabled
      slaves=b-e2,b-e3 mode=balance-alb primary=none link-monitoring=mii-type1
      arp-interval=100ms arp-ip-targets="" mii-interval=100ms down-delay=0ms
      up-delay=0ms lacp-rate=30secs transmit-hash-policy=layer-2

Here’s what the interfaces show when the cables are pulled from one of the bonds

/interface print
Flags: D - dynamic, X - disabled, R - running, S - slave
 #     NAME                                   TYPE               MTU L2MTU  MAX-L2MTU
 0  R  interweb-e1                            ether             1500  1526       1526
 1     a-e2                                  ether             1500  1522       1522
 2     a-e3                                  ether             1500  1522       1522
 3  R  b-e4                                 ether             1500  1522       1522
 4  R  b-e5                                 ether             1500  1522       1522
 5  R  bond-b                               bonding           1500
 6  R  bond-a                                bonding           1500
 7     vrrp-interweb                          vrrp              1500
 8     vrrp-a                                vrrp              1500
 9     vrrp-b                               vrrp              1500

interface 6 (bond-a) should not be running!!

Just in case the RB450 won’t work with mii-type1 link monitoring I’ll try type2. Any other suggestions for why the bond stays running even when all the slaves have been pulled? Also, why does pulling 1 slave or reconnecting it trigger a vrrp failover. The up-delay and down-delay are set to 0 (default). Have I made some configuration error elsewhere?

Thanks,
Matt

Any ideas on this bonding issue? Has anyone experienced this before?

Ta,
Matt