When we set vhost-user interface as inbound for SNAT, LISP is not sending map requests to mapping server. Instead, map requests are mistakenly translated by NAT and dropped. Please notice trace [1] and a corresponding fib table 3 output [2]

When we removed nat inbound from vhost-user-interface, map request was forwarded to LISP mapping server and the enry was resolved successfuly in fib table 3.

So it does seems like LISP and SNAT do not cooperate.

Note, for some unknown reason this does not happen for every VM, some do not have this problem and are able to send a map request.

[1] SNAT_INBOUND_APPLIED_ON_VHOST.txt

[2] FIB_TABLE.txt