Contents

Configuring normal Layer 2 forwarding· 1

About normal Layer 2 forwarding· 1

Restrictions: Hardware compatibility with Layer 2 forwarding· 1

Display and maintenance commands for Layer 2 forwarding· 1

Configuring fast Layer 2 forwarding· 1

About fast Layer 2 forwarding· 1

Restrictions: Hardware compatibility with fast Layer 2 forwarding· 1

Display and maintenance commands for fast Layer 2 forwarding· 2

Configuring normal Layer 2 forwarding

About normal Layer 2 forwarding

When an incoming frame's destination MAC address does not match any Layer 3 interface's MAC address, normal Layer 2 forwarding forwards the frame through a Layer 2 interface.

The device uses the destination MAC address of the frame to look for a match in the MAC address table.

·     The device forwards the frame out of the outgoing interface in the matching entry if a match is found.

·     The device floods the frame to all interfaces in the VLAN of the frame if no match is found.

Normal Layer 2 forwarding is enabled by default.

Restrictions: Hardware compatibility with Layer 2 forwarding

This feature is supported only on Layer 2 Ethernet ports on Ethernet switching modules:

On Layer 2 Ethernet switching modules of MSR devices that are operating in IRF mode, Layer 2 forwarding across member devices is not supported. On SIC Layer 2 Ethernet switching modules, Layer 2 forwarding across member devices and slots is not supported.

Layer 2 forwarding across slots that reside on the same device is supported if multiple HMIM-24GSW, HMIM-24GSWP, HMIM-8GSW, or HMIM-8GSWF Layer 2 Ethernet switching modules are installed on the following devices:

·     MSR5660.

·     MSR5680.

Layer 2 forwarding across slots that reside on the same device is not supported on MSR5620 devices that are installed with multiple HMIM-8GSW or HMIM-8GSWF Layer 2 Ethernet switching modules.

On MSR56 devices:

·     Layer 2 forwarding across slots is supported if multiple HMIM Layer 2 Ethernet switching modules are installed on the same SPE-S1 module.

·     Layer 2 forwarding across slots is not supported if multiple HMIM Layer 2 Ethernet switching modules are installed on the same SPE-S3 module.

Display and maintenance commands for Layer 2 forwarding

Execute display commands in any view and reset commands in user view.

Configuring fast Layer 2 forwarding

About fast Layer 2 forwarding

Fast Layer 2 forwarding improves packet forwarding efficiency by using a high-speed cache and flow-based technology. It identifies a flow by using the following items:

·     Source IP address.

·     Source port number.

·     Destination IP address.

·     Destination port number.

·     Protocol number.

·     Input interface.

·     Output interface.

·     VLAN ID.

Fast Layer 2 forwarding creates an entry in a high-speed cache by obtaining the forwarding information of a flow's first packet. Subsequent packets of the flow are forwarded based on the entry.

Fast Layer 2 forwarding is enabled by default.

Restrictions: Hardware compatibility with fast Layer 2 forwarding

This feature is supported only on Layer 2 Ethernet ports on Ethernet switching modules:

On Layer 2 Ethernet switching modules of MSR devices that are operating in IRF mode, Layer 2 forwarding across member devices is not supported. On SIC Layer 2 Ethernet switching modules, Layer 2 forwarding across member devices and slots is not supported.

Layer 2 forwarding across slots that reside on the same device is supported if multiple HMIM-24GSW, HMIM-24GSWP, HMIM-8GSW, or HMIM-8GSWF Layer 2 Ethernet switching modules are installed on the following devices:

·     MSR5660.

·     MSR5680.

Layer 2 forwarding across slots that reside on the same device is not supported on MSR5620 devices that are installed with multiple HMIM-8GSW or HMIM-8GSWF Layer 2 Ethernet switching modules.

On MSR56 devices:

·     Layer 2 forwarding across slots is supported if multiple HMIM Layer 2 Ethernet switching modules are installed on the same SPE-S1 module.

·     Layer 2 forwarding across slots is not supported if multiple HMIM Layer 2 Ethernet switching modules are installed on the same SPE-S3 module.

Display and maintenance commands for fast Layer 2 forwarding

Execute display commands in any view.

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