Configuring CoS for Tunnels

To configure CoS for GRE and IP-IP tunnels, perform the following configuration tasks:

To configure the tunnel, include the tunnel statement at the [edit interfaces ip-fpc/pic/port unit logical-unit-number] or [edit interfaces gr-fpc/pic/port unit logical-unit-number] hierarchy level.
To rewrite traffic on the outbound interface, include the rewrite-rules statement at the [edit class-of-service] and [edit class-of-service interfaces interface-name unit logical-unit-number] hierarchy levels. For GRE and IP-IP tunnels, you can configure IP precedence and DSCP rewrite rules.
To classify traffic on the inbound interface, you can configure a behavior aggregate (BA) classifier or firewall filter. Include the loss-priority and forwarding-class statements at the [edit firewall filter filter-name term term-name then] hierarchy level. Or you can include the classifiers statement at the [edit class-of-service] hierarchy level.
For a GRE tunnel, the default is to set the ToS bits in the outer IP header to all 0s. To copy the ToS bits from the inner IP header to the outer, include the copy-tos-to-outer-ip-header statement at the [edit interfaces gr-fpc/pic/port unit logical-unit-number] hierarchy level. (This inner-to-outer ToS bits copying is already the default behavior for IP-IP tunnels.)