If you’re using security group tags (SGTs)
in a Cisco TrustSec network, it’s a best practice to deploy inline firewalls
in either Layer 2 or virtual wire mode. However, if you need to
use a Layer 3 firewall in a Cisco TrustSec network, you should deploy
the Layer 3 firewall between two SGT exchange protocol (SXP) peers,
and configure the firewall to allow traffic between the SXP peers.