Description

This document provides inet6 Firewall-Filter configuration required to match inbound GRE encapsulated packets. The tunnel originates on the CMTS and terminates on the WAG.


(2606::0:f538:4023/128 ) CMTS ------ Core ------ PTX ae110 ------ Wireless-Access-Gateway (2603:90f4:600::1/128)


Solution

Configure Firewall Filter

re0# show | compare 
May 13 08:51:52
[edit interfaces ae111 unit 0 family inet6 filter]
+        input GRE-AE111_IN;
[edit firewall family inet6]
+     filter GRE-AE111_IN {
+         interface-specific;
+         term 1 {
+             from {
+                 source-address {
+                     2603:90f4:600::1/128;
+                 }
+                 destination-address {
+                     2606::0:f538:4023/128;
+                 }
+                 next-header gre;
+             }
+             then {
+                 count GRE_AE111_IN;
+                 accept;
+             }
+         }
+         term 2 {
+             then {
+                 accept;
+         }
+     }



Apply FF on the interface that connects to the endpoint


set interfaces ae110 unit 0 family inet6 filter input GRE-AE111_IN

Verify the matched packets


root@re0> show firewall filter GRE-AE111_IN-ae111.0-i     
May 13 08:54:12

Filter: GRE-AE111_IN-ae111.0-i                                 
Counters:
Name                                                Bytes              Packets
GRE_AE111_IN-ae111.0-i                               1840                    5
re0> show firewall log           
Log :
Time      Filter    Action Interface           Protocol        Src Addr                         Dest Addr
21:53:44  pfe       A      ae111.0             GRE             2603:90f4:600::1                 2606:6000:4fc0:16:d421:2137:f538:4023
21:53:53  pfe       A      ae111.0             GRE             2603:90f4:600::1                 2606:6000:4fc0:16:d421:2137:f538:4023
21:54:03  pfe       A      ae111.0             GRE             2603:90f4:600::1                 2606:6000:4fc0:16:d421:2137:f538:4023
21:54:05  pfe       A      ae111.0             GRE             2603:90f4:600::1                 2606:6000:4fc0:16:d421:2137:f538:4023
21:54:08  pfe       A      ae111.0             GRE             2603:90f4:600::1                 2606:6000:4fc0:16:d421:2137:f538:4023
21:54:12  pfe       A      ae111.0             GRE             2603:90f4:600::1                 2606:6000:4fc0:16:d421:2137:f538:4023


Modification History

2025-06-27 : Article Created

2026-06-11 : Mark to be external