Rewrite Operations - Cisco ASR 920 Series Configuration Manual Ethernet Router

Ethernet Virtual Connections Configuration
EFPs that are not configured with an explicit group_id do not belong to any group.
You can configure no more than 128 service instances per bridge domain. These 128 EFPs can be distributed
among split-horizon groups 0 to 13.
VPLS uses a reserved internal split group 15 which does not overlap with manually configured split groups.
In case VPLS is configured on same bridge domain, scale of 128 EFPs can still be achieved on the same
bridge domain.
128 EFPs and 64 VFIs are supported on the same bridge domain.
Restrictions
• Maximum number of EFPs per bridge-domain is 128. The EFPs can be distributed among split-horizon
• VPLS uses the reserved internal Split-horizon group 15 which does not overlap with manually configured
• 64 VFIs are supported on the same bridge-domain.

Rewrite Operations

You can use the rewrite command to modify packet VLAN tags. You can use this command to emulate
traditional 802.1Q tagging, where packets enter a router on the native VLAN and VLAN tagging properties
are added on egress. You can also use the rewrite command to facilitate VLAN translation and QinQ.
The supported rewrite commands:
• rewrite ingress tag pop 1 symmetric
• rewrite ingress tag pop 2 symmetric
• rewrite ingress tag push dot1q vlan-id symmetric
Enter the rewrite ingress tag pop {1 | 2} symmetric service-instance configuration mode command to specify
the encapsulation adjustment to be performed on the frame ingress to the EFP. Entering pop 1 pops (removes)
the outermost tag; entering pop 2 removes two outermost tags.
Note The symmetric keyword is required to complete rewrite to configuration.
When you enter the symmetric keyword, the egress counterpart performs the inverse action and pushes (adds)
the encapsulation VLAN. You can use the symmetric keyword only with ingress rewrites and only when
single VLANs are configured in encapsulation. If you configure a list of VLANs or a VLAN range or
encapsulation default or encapsulation any, the symmetric keyword is not accepted for rewrite operations.
Static MAC Addresses
The router supports multicast static MAC addresses, which allow you to enable multicast at the layer 2 level.
You can use multicast static MAC addresses to forward multicast packets to specific EFPs on a network.
groups 0 to 13.
split groups. In case VPLS is configured on the same bridge-domain, the scale of 128 EFPs is achieved
on the same bridge-domain.
Carrier Ethernet Configuration Guide (Cisco ASR 920 Series)
Rewrite Operations
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