Working with the GARP Chunk Mechanism
Check Point Maestro R80.20SP Administration Guide | 67
Working with the GARP Chunk Mechanism
In This Section:
Description
When Proxy ARP is enabled, the Firewall responds to ARP requests for hosts other than itself. When
failover occurs between Security Appliances, the new Active Security Appliance sends Gratuitous ARP
(GARP) Requests with its own (new) MAC address to update the network ARP tables.
To prevent network congestion during failover, GARP Requests are sent in user defined groups called
chunks. Each chunk contains a predefined number of GARP Requests based on these parameters:
n
The number of GARP Requests in each chunk.
n
High Availability Time Unit (HTU) - Time interval (1 HTU = 0.1 sec), after which a chunk is sent.
n
The chunk mechanism iterates on the proxy ARP IP addresses, and each time sends GARP
Requests only for some of them until it completes the full list.
When the iteration sends the full list, it waits
N
HTUs and sends the list again.
Configuration
For example, to send 10 GARP Requests each second, set the value of the kernel parameter
fwha_
refresh_arps_chunk
to 1:
# g_fw ctl set int fwha_refresh_arps_chunk 1
To send 50 GARP Requests each second, set the value of the kernel parameter
fwha_refresh_arps_
chunk
to 5:
# g_fw ctl set int fwha_refresh_arps_chunk 5
