Hello,
I have two CCR’s connected together with CSR between them. I’ve set vlan interface and then vrrp interface on that vlan. Below is simplified configuration of CCR routers. CSR is just plain switch.
R1:
/interface vlan
add interface=ether3 name=vlan101 vlan-id=101
/interface vrrp
add interface=vlan101 name=vrrp101 priority=200 vrid=101 preemption-mode=yes
/ip address
add address=100.100.101.254/24 interface=vlan101 network=100.100.101.0
add address=100.100.101.1/24 interface=vrrp101 network=100.100.101.1
R2:
/interface vlan
add interface=ether3 name=vlan101 vlan-id=101
/interface vrrp
add interface=vlan101 name=vrrp101 priority=100 vrid=101 preemption-mode=yes
/ip address
add address=100.100.101.253/24 interface=vlan101 network=100.100.101.0
add address=100.100.101.1/24 interface=vrrp101 network=100.100.101.1
The problem raises when R2 (lower priority) becomes master.
Scenario 1:
- both R1 and R2 boot up, go to backup state, then since R1 booted a bit faster it becomes master
- since R2 has lower priority, and preemption is enabled it stays as backup and listens for advertisements
- when I unplug R1, the R2 becomes master
- after plugging R1 back to network, it gets advertisements from R2 with priority 100, and decides to become master since he has higher priority (200)
- now I have 2 master routers, both responding to VRRP IP, and neither want to go backup
(I would expect R2 to go to backup mode)
Scenario 2:
- both R1 and R2 boot up, go to backup state, but this time R2 booted a bit faster and became master
- since R1 has higher priority, and preemption is enabled it becomes a master too
- same as scenario 1, I have 2 master routers, both responding to VRRP IP
Is this behaviour desired? I can’t really think of sane infrastructure where You would want two routers to have the same IP after a breakdown…