Egress Shaping for Fabric Extend Tunnels on Fabric IPsec Gateway

Table 1. Egress Tunnel Shaping product support
Feature	Product	Release introduced
Egress Shaper for Fabric Extend tunnels on Fabric IPsec Gateway virtual machine	5320 Series	Not Supported
	5420 Series	Not Supported
	5520 Series	Not Supported
	5720 Series	Fabric Engine 8.7 Supported on 5720-24MXW and 5720-48MXW
	7520 Series	Fabric Engine 8.10
	7720 Series	Fabric Engine 8.10
	VSP 4900 Series	VOSS 8.3.1 Supported on VSP4900-12MXU-12XE and VSP4900-24XE
	VSP 7400 Series	VOSS 8.3.1

You can configure the egress shaping rate to limit egress bandwidth for tunnels on the Fabric IPsec Gateway Virtual Machine (VM).

Egress Tunnel Shaping shapes unicast, multicast, and unknown unicast egress traffic on the tunnel.

Eight traffic queues are created for the tunnel traffic when a new shaper is configured. Packets are mapped to any of these queues based on the internal Class of Service (CoS) of the packets. When multiple tunnels use the common shaper value, an internally unique shaper is associated for each tunnel. The following table shows the default minimum weight for each queue.


Queue	Default Minimum Weight
0	5
1	20
2	30
3	40
4	50
5	50
6	Rate limited to 50% of configured shaper rate
7	Rate limited to 5% of configured shaper rate

Queues 6 and 7 are rate limited and have a higher priority. The maximum traffic allowed out of queue 6 and queue 7 would be shape rate/2 (50% bandwidth) and shape rate/20 (5% bandwidth).

Considerations

Consider the following when you configure the egress shaper rate:

If the ingress data traffic receives excessive packets with the following DSCP or 802.1p values (high priority control packets) and egress shaping is configured, a IS-IS flap can be seen.


DHCP value	802.1p value
0x28	6
0x2E	6
0x2F	6
0x30	7
0x38	7

The egress tunnel shaping rate is impacted if the incoming packet size is greater than the Fabric Extend tunnel MTU. This is due to the additional packet header required for fragmentation.