Possible to set curl source as IP from subnet not directly configured on F5?
I need to run a curl to mimic traffic as if coming from the serverside of an existing Virtual Server (specific setup means I can't just curl to the clientside of the Virtual Server unfortunately).
The problem is that the serverside uses SNAT (not automap). The SNAT IP is only "logical" - i.e. the F5 doesn't have a VLAN or self IPs aligned to the subnet that the SNAT IP is taken from. The VS sets the source to the SNAT IP and then external routing directs return traffic for that IP back to the F5 over a "real" VLAN.
This is causing a problem when I try to mimic the VS originated traffic by setting an 'interface' for curl, i.e. using:
curl --interface x.x.x.x
where x.x.x.x is the SNAT IP applied on the VS.
Curl produces the error:
* bind failed with errno 99: Cannot assign requested address
* Closing connection 0
curl: (45) bind failed with errno 99: Cannot assign requested address
Is there a way to force curl to use an IP that doesn't actually relate to a "real" interface?