Conversational ARP

Conversational ARP reduces the number of cached ARP entries by programming only active flows into the forwarding plane. This feature helps to optimize the use of hardware resources.

In many scenarios, software requirements for ARP entries are beyond the capacity of the hardware. Conversational ARP limits storage-in-hardware to active ARP entries. Aged-out entries are deleted automatically.

By default, the aging-out threshold is 300 seconds. You can change the threshold to any value from 60 through 100,000 seconds, either before or during enablement. Entries that do not have at least one conversation before aging-out are deleted from the cache. Each conversation restarts the clock for that entry.

Aging-out is also influenced by the enablement and disablement cycle:

Under conversational ARP, which is disabled by default, a fast-aging policy of 60 seconds (not configurable) applies to all entries in the ARP cache.
Upon disablement, the conversational ARP timer no longer applies. All current and new entries become permanent.

Static ARPs are not subject to conversational behavior.

Note

Conversational ARP is supported on SLX 9150 and SLX 9250.