VRRP and session synchronization
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Posted by pwidman
I have a customer who is implementing VCS along with VRRP this weekend and would like to use a dedicated port or trunk for session synchronization. After reading the 2.6.1 configuration guide section for VRRP it is not clear to me if this is possible. I recall that it was possible but I do not recall the configuration
If it is possible does anyone have a configuration example?
Thanks
I have a customer who is implementing VCS along with VRRP this weekend and would like to use a dedicated port or trunk for session synchronization. After reading the 2.6.1 configuration guide section for VRRP it is not clear to me if this is possible. I recall that it was possible but I do not recall the configuration
If it is possible does anyone have a configuration example?
Thanks
0
Comments
Hi,
In our "legacy-HA", you can specify one remote AX IP@ you want to use to send the sessions sync to.
In our new-VRRP-HA (introduced in 2.6), you can have more than 2 AXs in HA.
So that option (specify one remote AX IP@) doesn't make sense since you may have multiple remote AXs.
So in 2.6.1 with the new-VRRP-HA, the AX will automatically and transparently learn all the IP@ from all the remote AX(s) and will select one of them to send the session sync.
Note: The remote AXs send multicast (by default) on all their interfaces. The AX will learn all the remote AXs IP@ that way. The AX will use the first IP@ learned from the remote AXs for session sync.
Conclusion: In 2.6.1 you don't specify the remote AXs IP@ to send the sessions sync. The first one learned is used.
Note: If you want to use by deafult a specific interface to send the sessions sync, our coming 2.6.2 will help you
From 2.6.2, you'll have the ability to specify on your AX to use by default the AXs remote IP@ learned on a specific interface. So as long as the AX learns the remote AXs IP@ on that interface => AX will use that one.
Dimitri
You can configure vrrp-a in the shared partition and use this vrrp-a interface for all L3V session sync. Also, make sure that you have configured the IPs on eth 8 for each device: For example:
interface ethernet 1/8
ip address 10.10.10.1 255.255.255.252
!
!
interface ethernet 2/8
ip address 10.10.10.2 255.255.255.252
vrrp-a enable
vrrp-a interface ethernet 8 device 1
vrrp-a interface ethernet 8 device 2
Thanks guy.
Indeed you can change the default settings (all interfaces are used to send the VRRP multicast packets and one is used for the session sync).
You can configure the specific AX interface or specific AX interfaces you want to send the VRRP multicast packets with the command you mentioned.
If you have 1 interface => that interface is used for the session sync.
If you have multiple interfaces => one of them (not configurable - see previous comment) is used for the session sync.
Important Note:
If you have multiple interfaces used on AX, for instance:
Internet / \ / \ Router-active Router-pass | | | | (VIPs-act) (VIPs-pass) AX1 --- interlink --- AX2 | | \ / \ / ServersIt is recommended to not configure only 1 single interface to send the VRRP multicast packets (for instance interlink in the example above).
Indeed if that interlink goes down , both AXs won't see each other anymore => both will turn active => IP conflicts on the VIP.
So if you want to have VRRP messages and session sync sent over only 1 link (interlink in the example above), we recommend you use a trunk of 2 interfaces for that interlink.
Dimitri