H3C Technologies H3C S3600 Series Switches - Manual (Page 619)

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Resilient ARP Configuration
When configuring resilient ARP, go to these sections for information you are interested in:
z Introduction to Resilient ARP
z Configuring Resilient ARP
z Resilient ARP Configuration Example
The features in this chapter apply to S3600-EI series switches only.
Introduction to Resilient ARP
In intelligent resilient framework (IRF) network application, normally you need to connect redundancy
links between the fabric and other devices to support the resilient network. But if the connections inside
the fabric break off, the fabric splits. In this case, the redundancy link may connect with two or more
Layer 3 devices with the same configurations in the same network. Thus these devices operate the
same routing function. Adopting the Resilient ARP function can avoid this. Resilient ARP can find
whether there are the same Layer 3 devices in the network. If so, it keeps one device as the Layer 3
device, and changes the other devices to be the Layer 2 devices.
The state machine of Resilient ARP has six states which are Initialize, LisentForL3Master, L3Master,
L3slave, L2Master, and L2slave. L3Master sends Resilient ARP packets periodically to notify other
fabrics that the local fabric is in the Layer 3 state.
Resilient ARP implements the system state switching by sending/receiving Resilient ARP packets
periodically, so as to determine a device to work as a Layer 3 device or a Layer 2 device.
Configuring Resilient ARP
Resilient ARP configuration includes:
z Enable/disable the Resilient ARP function.
When Resilient ARP function is enabled, the system can deal with the devices according to the current
state. When the connections inside a fabric break off, Resilient ARP can send Resilient ARP packets
through the VLAN interface where the redundancy link resides, so as to determine a device to work as
a Layer 3 device or as a Layer 2 device.
z Configure the VLAN interface through which Resilient packets are sent.
You can use the following commands to configure the VLAN interface through which Resilient packets
are sent. When no VLAN interface is specified, Resilient packets are sent through the default VLAN
interface.
Follow these steps to configure the Resilient ARP function: