Example for Configuring Transparent Transmission of Protocol Packets in a VLAN

Networking Requirements

Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support this function.

A company has multiple subsidiary companies. When the parent company communicates with a subsidiary company through the core switch, the core switch processes the packets before forwarding them. If multiple subsidiary companies communicate with the parent company simultaneously, then network performance deteriorates, lowering communication efficiency and increasing communication costs. Transparent transmission of protocol packets in a VLAN can be configured on the core switch to solve this problem.

In Figure 1, after transparent transmission of protocol packets in a VLAN is enabled, the Switch forwards data from the specified VLAN without sending the data to its CPU. This improves the processing efficiency, reduces communication costs, and minimizes the probability of malicious attacks on the Switch.

Figure 1 VLAN transparent transmission

Configuration Roadmap

Create VLANs.
Enable transparent transmission of protocol packets in a VLAN.
Add Ethernet interfaces to VLANs.

Procedure

Configure the Switch.

# Create VLANs.

<HUAWEI> system-view
[HUAWEI] sysname Switch
[Switch] vlan batch 10 20

# Enable transparent transmission of protocol packets in a VLAN.

[Switch] vlan 20
[Switch-vlan20] protocol-transparent
[Switch-vlan20] quit

# Add interfaces to the VLANs.

[Switch] interface gigabitethernet 0/0/1
[Switch-GigabitEthernet0/0/1] port link-type hybrid
[Switch-GigabitEthernet0/0/1] port hybrid tagged vlan 10
[Switch-GigabitEthernet0/0/1] quit
[Switch] interface gigabitethernet 0/0/2
[Switch-GigabitEthernet0/0/2] port link-type hybrid
[Switch-GigabitEthernet0/0/2] port hybrid tagged vlan 10 20
[Switch-GigabitEthernet0/0/2] quit
[Switch] interface gigabitethernet 0/0/3
[Switch-GigabitEthernet0/0/3] port link-type hybrid
[Switch-GigabitEthernet0/0/3] port hybrid tagged vlan 20
[Switch-GigabitEthernet0/0/3] quit

Configure SwitchA and SwitchB. Add upstream interfaces on SwitchA and SwitchB to VLAN 10 and VLAN 20 in tagged mode, and add downstream interfaces to VLAN 10 and VLAN 20 in default mode.
Verify the configuration.
# After the configuration is complete, run the display this command on VLAN 20. The command output shows that transparent transmission of protocol packets in a VLAN is enabled.
```
[Switch] vlan 20
```
```
[Switch-vlan20] display this
#
vlan 20
 protocol-transparent
#
return
```

Configuration Files

Switch configuration file

#
sysname Switch
#
vlan batch 10 20
#
vlan 20
 protocol-transparent
#
interface GigabitEthernet0/0/1
 port link-type hybrid
 port hybrid tagged vlan 10
#
interface GigabitEthernet0/0/2
 port link-type hybrid
 port hybrid tagged vlan 10 20
#
interface GigabitEthernet0/0/3
 port link-type hybrid
 port hybrid tagged vlan 20
#
return