topic Re: Multiple IP addresses on an interface in General Topics

Multiple IP addresses on an interface

nthen — Tue, 04 Jun 2013 17:28:27 GMT

I know that I can add a second IP to my outside interface by using a /32 instead of /24 like the first one has. My question comes in with routing. My default route shows a 0.0.0.0/0 going out ethernet1/1. Since this interface has 2 IPs what IP does it use for the routing? Will it use the one with a /24 or /32.

Re: Multiple IP addresses on an interface

VinceM — Tue, 04 Jun 2013 17:49:02 GMT

Hi,

For routing ... none of them, your interface addresse will never appear in the routing stuff.

For NAT, depend wich IP you have selected in the Policy NAT rule.

"Normally" (don't like this word) you don't need to configure multiple IP adress on your outside interface, if you've got a router connected on it, with gratuitous arp, all your traffic should be redirected to your outside fw interface.

Exept if second IP will be used for:

GP portal / Gateway

IP for nating

Re: Multiple IP addresses on an interface

nthen — Tue, 04 Jun 2013 17:55:54 GMT

The second IP will be used for a second GP Portal, so I believe it is needed. For NAT I am using something complete different in my range rather than eth1/1's IP.

Re: Multiple IP addresses on an interface

Retired Member — Tue, 04 Jun 2013 18:26:10 GMT

alternatively you can add your each /32 ip address as untagged subinterface option.You can then use any for GP, and also you can use different management profile for each.