Proxy ARP Support for Reachable Routes in the Network

You can configure whether the switch replies to ARP requests on a specified VLAN by proxy ARP if the route to the IP address is reachable, or only if proxy ARP entries have been created.

If an ARP request is received by the switch, it checks the ExtremeXOS proxy ARP table (user adds the entries through the CLI). If it is present, an ARP reply is sent. If not present, it searches for the entry in the kernel route table. If this IP address is reachable, then the ARP reply is sent. The default behavior is for the switch to reply to ARP requests on the specified VLAN(s) by proxy ARP only if proxy ARP entries have been created.

The following table summarizes the this feature's behavior:

reachable

entry-required

(or command not configured)

Entry present in proxy ARP Table (static entry added through command configure iparp add ip_addr {vr vr_name} mac ) Reply to ARP request Reply to ARP request
Static entry not present in proxy ARP table Reply to ARP request if route is reachable No reply to ARP request
No static entry, but route reachable. Reply to ARP request
No static entry and route is not reachable No reply to ARP request
Static entry present and route is reachable Reply to ARP request
No static entry and route is not reachable No reply to ARP request
Route reachable Reply to ARP request
Route not reachable No reply to ARP request

Supported Platforms

All ExtremeSwitching Universal switches.

Limitations

  • No support of SNMP.
  • For this feature the statistics of ARP send “Out Response” is incremented.

To configure proxy ARP support for reachable routes, use the command:

configure iparp proxy [vlan all | {vlan} vlan_name] [reachable | entry-required]

To view the status for proxy ARP reachable routes on a VLAN, use the command:

show vlan {virtual-router vr-name}