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Is it possible to have a virtual local L3 loopback interface

Hi everyone,


Is it possible to have a local virutal IP address similar to what cisco calls loopback interface ?


I am trying to achieve a network topology as follows:




The subnet between the router and F5 is a /30 RFC 1918 subnet used for routing. F5 has a Self IP 10.0.0.X/30 on this subnet and a default route pointing to 10.0.0.Y


In F5 I have DNS service listening on a public IP, e.g This IP is also configured as a Self IP


Incoming traffic is OK: traffic from internet is reaching by the mean of a route configured on the router, and return traffic from F5 has as a source IP.


However, traffic originating from F5 is not working because its source IP is always 10.0.0.X, so packets get lost. I would like to source the outgoing traffic from SNAT didn't help here.


Also, when I test with a ping request and manually source the traffic from using the -I argument, outbound traffic is OK. I would like to have this exact behavior for data traffic (iquery, monitoring ...etc).


The customer has requirements to not use public IPs for interconnection links.


Any help is appreciated