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Daniel_Beckham_'s avatar
Daniel_Beckham_
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Oct 20, 2015

Can IP addresses assigned to loopback interfaces in a LineRate CARP fail over configuration be on the same subnet as the public interface?

Can IP addresses assigned to loopback interfaces in a LineRate CARP fail over configuration be on the same subnet as the public interface?

 

e.g. If the router is 1.1.1.1, and the CARP IP on em1 (on both devices) is 1.1.1.2, can I assign 1.1.1.10 as a VIP on the loopback interfaces and add a static route to send requests for 1.1.1.10 to the CARP IP 1.1.1.2? The documentation doesn't say you can't, but every example uses a separate subnet for the VIPs assigned to the loopback interfaces.

 

I'm in the process of having static routes added to our upstream provider's router and I'm trying to determine if we can reuse addresses from the same subnet we already have, or if we will have to requests a new, separate subnet for the VIPs. Before we go through the work of adding the static routes, I want to make sure I'm not choosing a configuration that will never work.

 

1 Reply

  • Hi Daniel, We have confirmed that having a /32 IP on the loopback interface that is on the same subnet does work. One thing to make sure is to configure the loopback interface before you admin-online the VIP. Otherwise ARP is disable and you may need to restart the instances.