Some testing scenarios might require two ports to be wired 'back-to-back'. Instead of using a physical cable, you can configure a virtual wire between two ports. The virtual wire forwards traffic from one port to the other port with minimal filtering or modification of the packets.
- ACL mirroring is not supported.
- You can select ports that are already ingress and egress mirror sources.
- Go to Switch > Virtual Wires.
- Select Add Virtual Wire to create a new virtual wire.
- Enter a name and select the ports for first member and second member.
- Select Add to save the changes.
Use the following commands to configure a virtual wire:
config switch virtual-wire
set first-member <port-name>
set second-member <port-name>
set vlan <vlan-id>
Virtual wire ports set a special Tag Protocol Identifier (TPID) in the VLAN header. The default value is 0xdee5, a value that real network traffic never uses.
Use the following commands to configure a value for the TPID:
config switch global
set virtual-wire-tpid <hex value from 0x0001 to 0xFFFE>
Use the following command to display the virtual wire configuration:
diagnose switch physical-ports virtual-wire list
port1(1) to port2(2) TPID: 0xdee5 VLAN: 4011 port3(3) to port4(4) TPID: 0xdee5 VLAN: 4011 port5(5) to port25(25) TPID: 0xdee5 VLAN: 4011 port7(7) to port8(8) TPID: 0xdee5 VLAN: 4011
- Ports have ingress and egress VLAN filtering disabled. All traffic (including VLAN headers) is passed unchanged to the peer. All egress traffic is untagged.
- Ports have L2 learning disabled.
- Ports have their egress limited to their peer and do no allow egress from any other ports.
- The system uses TCAM to force forwarding from a port to its peer.
- The TCAM prevents any copy-to-cpu or packet drops.