Server failover

[chpmotry]

Hi guys. 

In one scenario, I have a primary server and a backup server. I want the backup server and the main server to be up at the same time, and the backup server can be in sync with the main server, and if the main server goes down, the backup server can respond to external clients. In your opinion, to implement this scenario, should the IP of the backup server and the main server be different, and what method can I use using Cisco's layer two or three switching tools?

The method that comes to my mind is to define in the fortigate firewall that if the ping of the main server is interrupted, a nat will be executed to change the destination to the Backup server.

[Reza Sharifi]

Hi,

You probably need to put both servers in the same subnet with 2 different IPs and a virtual IP representing both servers. Usually this is accomplished with a load balancer. Maybe there is an application that can cluster the 2 servers with one IP if you don't have a load balancer. If you can configure it this way, whichever server is available can respond, and the end users will not notice if there is a server failure.

HTH

[balaji.bandi]

But you have not mentioned what is connectivity L3 and other switches is this layer 2 or Layer 3 ?

is this switches are stack or colocated in different places ?

As mentioned you can also do with DNS LB if you like to do also look MS Cluster. (if MS servers?)

[chpmotry]

Thank you for your comment. I will explain to you in the picture. Links are layer two.

[Reza Sharifi]

Yes, both servers are in access vlan 2, which is good. Now, as I said above, if you can cluster the 2 servers together and make them logically one server with 2 physical IPs and one virtual IP, redundancy should work. This way, you use the same IP and name for the whole cluster.

HTH

[chpmotry]

Thanks for your useful comments. If i want to use layer3 link between this two server (primary and backup ) and both servers ping each other,can i still implementing the failover clustering way in MS SERVER?

 

[Reza Sharifi]

I am not familiar with server clustering, but from what I understand, in other for clustering to work correctly, the connection between the server needs to simply be layer-2 (both in one vlan), but there could be other solutions using layer-3 that I am not aware of.

HTH