So, at $work[0] we needed to do a “many to one” SNAT on Cisco IOS. I’d only ever previously done this by SNAT’ing to an interface, however this required specifying the IP.
My Google-fu failed me, I could turn up how to do the “SNAT to interface” and “SNAT one to one from a network to a pool” but not quite what we needed.
So I thought I’d try having a pool with a single IP in it, ala:
ip access-list extended SNAT_SRC_ACL
permit ip w.x.y.z 0.0.0.63 any
ip nat pool SNAT_POOL a.b.c.d a.b.c.d netmask 255.255.255.0
ip nat inside source list SNAT_SRC_ACL pool SNAT_POOL overload
Which worked!
And then five seconds later a workmate found a site that described exactly this technique. Argh!