# dynamic interfaces need not exist at load-time, but names must start
# with a letter. catches common macro typo cases of ($ext_ip) vs. ($ext_if)

nat on lo0 from any to any -> (lo0)
nat on lo0 from any to any -> (lo0:0)
nat on lo0 from any to any -> (nonexistent0)
nat on lo0 from any to any -> (nonexistent0:0)
nat on lo0 from any to any -> (10.1.2.3)
nat on lo0 from any to any -> (10.1.2.3:0)