I've got a situation that involves Microsoft's cluster service. It moves a Sql server to another physical server in case of a failover. The sql server's IP address doesn't change, but the mac address changes depending on the server that it moves to.
The problem that we're having is that the arp cache isn't timing out in the switch. Microsoft says that it's because the switch isn't forwarding gratuitous arp packets. How do I enable this?
I found that I can do an "ip arp gratuitous local", but I'm not sure that's going to do what I want.
ARP provides IP communication within a Layer 2 broadcast domain by mapping an IP address to a MAC address.
You can't map multiple MACs to an IP so for this to work, the server needs to release the MAC address from the switch table. This is often triggered when the device is powered down. If the device didn't release the MAC address properly, then the switch will wait until the mac-address-table aging time removes the stale entry. By default is set to 5 minutes:
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...