Specifications

VLAN Tunneling (VMANs)
ExtremeWare XOS 10.1 Concepts Guide 73
Displaying Protocol Information
To display protocol information, use the following command:
show protocol {<name>}
This show command displays protocol information, which includes:
• Protocol name.
• List of protocol fields.
• VLANs that use the protocol.
VLAN Tunneling (VMANs)
You can “tunnel” any number of 802.1Q and/or Cisco ISL VLANs into a single VLAN that can be
switched through an Extreme Ethernet infrastructure. A given tunnel is completely isolated from other
tunnels or VLANs. This feature is useful in building transparent private networks (VMANs) that need
point-to-point or point-to-multipoint connectivity across an Ethernet infrastructure. The VLAN tagging
methods used within the VMAN tunnel are transparent to the tunnel. For the MAN provider, the
tagging numbers and methods used by the customer are transparent to the provider.
To configure a VMAN tunnel, follow these steps:
1 Modify the 802.1Q Ethertype the switch uses to recognize tagged frames. Extreme Networks
recommends the use of IEEE registered ethertype 0x88a8 for deploying vMANs.
2 Configure the switch to accept larger MTU size frames (jumbo frames).
3 Create tunnels by creating VLANs and configuring member ports as tagged on switch-to-switch
ports and untagged on the ingress/egress ports of the tunnel.
Figure 7 illustrates a configuration with VMANs.
Figure 7: VMAN example
Two tunnels are depicted that have ingress/egress ports on each Extreme switch.
EX_066
1:1
1:2
31
Ports 1-4
Ports 5-8
32
Tunnel #1
ingress/egress
32
32
31
31
Tunnel #2
ingress/egress
vMAN core
Tunnel #1
ingress/egress
Tunnel #2
ingress/egress
Ports 1-4
Ports 1-4
Ports 5-8
Ports 5-8
Tunnel #1
ingress/egress
Tunnel #2
ingress/egress