[Networking-guide]Fix the wrong source MAC noted after routing
[Networking-guide]Fix the wrong source MAC noted after routing

backport: Liberty
backport: Kilo

Change-Id: I0708ff299c93482732d91520b5f32649f2cc3414
Closes-Bug: #1547637

AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals