protocol-transparent

Function

Using the protocol-transparent command, you can enable transparent transmission of protocol packets in a VLAN.

Using the undo protocol-transparent command, you can disable transparent transmission of protocol packets in a VLAN.

By default, transparent transmission of protocol packets is disabled in a VLAN.

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 command.

Format

protocol-transparent

undo protocol-transparent

Parameters

None

Views

VLAN view, VLAN-Range view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

When the device used as the gateway or Layer 2 switches is enabled with snooping functions such as DHCP/IGMP/MLD snooping, the device needs to parse and process protocol packets such as ARP, DHCP, and IGMP packets. The interface sends protocol packets without differentiating VLANs. That is, if any of the preceding snooping functions are deployed, protocol packets from all VLANs are sent to the CPU for processing.

If the device is a gateway of some VLANs or snooping functions is deployed in some VLANs, the device does not need to process protocol packets in other VLANs. After the protocol packets in other VLANs are sent to the CPU, the CPU needs to forward them to other devices. This mechanism is called software forwarding. Software forwarding affects the forwarding speed and efficiency of protocol packets because protocol packets need to be processed.

To address this issue, deploy transparent transmission of protocol packets in VLANs where protocol packets do not need to be processed. This function enables the device to transparently transmit the protocol packets in the VLANs to other devices, which improves the forwarding speed and efficiency.

The switch can transparently transmit the following protocol packets: CFM/ARP/BFD/DHCP/DHCPV6/HTTP/IGMP/MLD/ND/PIM/PIMv6/PPPoE/TACACS.

Precautions

Before running the protocol-transparent command, ensure that IGMP snooping or MLD snooping has been disabled in the VLAN. Otherwise, the configuration fails.
After the protocol-transparent command is executed in a VLAN view, the switch does not participate in protocol calculation in this VLAN.

Example

# Enable transparent transmission of protocol packets in VLAN 100.

<HUAWEI> system-view
[HUAWEI] vlan 100
[HUAWEI-vlan100] protocol-transparent

# Enable transparent transmission of protocol packets in VLAN 10 to 20.

<HUAWEI> system-view
[HUAWEI] vlan batch 10 to 20
[HUAWEI] vlan range 10 to 20
[HUAWEI-vlan-range] protocol-transparent