GRE Encap Firewall Filter

## Can be deleted if you want to encap all traffic
set firewall family inet filter gre_encap_1 term t1 match <INTERESTING TRAFFIC>

## Required
set firewall family inet filter gre_encap_1 term t1 then encapsulate tunnel_1
set firewall tunnel-end-point tunnel_1 ipv4 source-address <LOCAL LOOPBACK>
set firewall tunnel-end-point tunnel_1 ipv4 destination-address <REMOTE LOOPBACK>
set firewall tunnel-end-point tunnel_1 gre

## Apply to Interface
set interfaces xe-0/0/0 unit 0 family inet filter input gre_encap_1