Enabling Bridge Mode

VLAN stacking, also known as the 802.1ad standard, extends the original VLAN tagging technology by allowing VLAN packets to be tunneled in another VLAN tag. When allowing multiple VLAN tags in an Ethernet frame, together these tags constitute a tag stack. The advantages of the EEE 802.1ad are:

802.1Q has a 12-bit VLAN ID field, which has a theoretical limit of 212=4096 tags. With the growth of networks, this limitation has become more acute. A double-tagged frame has a theoretical limitation of 4096×4096=16777216, sufficient to accommodate network growth for the next several years.
The addition of a second tag allows operations that would not have been available had the VLAN ID field simply been expanded from 12 bits to 24 bits (or any other large value). Having multiple tags—the tag stack—allows switches to more easily modify frames.
A multi-tagged frame not only has multiple VLAN IDs, but has multiple VLAN header bit fields.
802.1ad is upward compatible with 802.1Q. Although 802.1ad is limited to two tags, there is no ceiling on the standard limiting a single frame to more than two tags, allowing for growth in the protocol. In practice, Service Provider topologies often anticipate and utilize frames having more than two tags.

Note: When enabling tunneling on a port or configuring the Bridge Mode, spanning tree and GARP must be shut down.

Note:

However, note that in the current software version, Dot1Q tunnel is not supported in interface level.

Execute the following commands to disable GVRP and GMRP, and shut down GARP and the spanning tree.

perform the following:

iS5comm# configure terminal

iS5comm(config)# set gvrp disable

iS5comm(config)# set gmrp disable

iS5comm(config)# shutdown garp

iS5comm(config)# shutdown spanning-tree

Exit from the Interface Configuration Mode

iS5comm(config)# end

Configure the Bridge mode of the Switch as “Customer”.

iS5comm(config)# bridge-mode customer

Enable GARP and spanning tree.

perform the following:

iS5comm(config)# no shutdown garp

iS5comm(config)# set gvrp enable

iS5comm(config)# set gmrp enable

iS5comm(config)# spanning-tree mode mst

Exit from the Global Configuration Mode

iS5comm(config)# exit

View the VLAN device configuration by executing the following show command.

perform the following:

iS5comm# show vlan device info

Vlan device configurations

--------------------------

Vlan Status                       : Enabled

Vlan Oper status                  : Enabled

Gvrp status                       : Enabled

Gmrp status                       : Enabled

Gvrp Oper status                  : Enabled

Gmrp Oper status                  : Enabled

Mac-Vlan Status                   : Enabled

Subnet-Vlan Status                : Disabled

Protocol-Vlan Status              : Enabled

Bridge Mode                       : Customer Bridge

Base-Bridge Mode                  : Vlan Aware Bridge

Traffic Classes                   : Enabled

Vlan Operational Learning Mode    : Hybrid

Hybrid Default Learning Mode      : IVL

Version number                    : 1

Max Vlan id                       : 4094

Max supported vlans               : 4094

Global mac learning status        : Enabled

Filtering Utility Criteria        : Enabled

Unicast mac learning limit        : 0

Execute the following command to disable GMRP and GVRP on port Gi 0/6.
```
iS5comm# configure terminal
```
```
iS5comm(config)# set port gvrp gigabitethernet 0/6 disable
```
```
iS5comm(config)# set port gmrp gi 0/6 disable
```
```
iS5comm(config)# interface gi 0/6
```
```
iS5comm(config-if)# switchport acceptable-frame-type untaggedAndPrioritytagged
```
- untaggedAndPrioritytagged—configures the acceptable frame type as untagged and priority tagged. As a result, only the untagged or priority tagged frames received on the port are accepted and subjected to ingress filtering. The tagged frames received on the port are rejected.
```
iS5comm(config-if)# switchport mode access
```

View the configuration details by executing the following show command.

iS5comm# show vlan port config port gigabitethernet 0/6

Vlan Port configuration table

-------------------------------

Port Gi0/6

Bridge Port Type                    : Customer Bridge Port

Port Vlan ID                        : 1

Port Acceptable Frame Type          : Admit Only Untagged and Priority Tagged

Port Mac Learning Status            : Enabled

Port Ingress Filtering              : Enabled

Port Mode                           : Access

Port Gvrp Status                    : Disabled

Port Gmrp Status                    : Disabled

Port Gvrp Failed Registrations      : 0

Gvrp last pdu origin                : 00:00:00:00:00:00

Port Restricted Vlan Registration   : Disabled

Port Restricted Group Registration  : Disabled

Mac Based Support                   : Enabled

Subnet Based Support                : Disabled

Port-and-Protocol Based Support     : Enabled

Default Priority                    : 0

Filtering Utility Criteria          : Default

Port Protected Status               : Disabled

Ingress EtherType                   : 0x8100

Egress EtherType                    : 0x8100

Egress TPID Type                    : Portbased

Allowable TPID 1                    : 0x0

Allowable TPID 2                    : 0x0

Allowable TPID 3                    : 0x0

Reflection Status                   : Disabled

-------------------------------------------------------

Note:

Verify that:

- Port Acceptable Frame Type is “Admit Only Untagged and Priority Tagged”
- Which enables Port Ingress Filtering