I have one unit Catalyst 6513 [Native IOS version 12.2(18)SXF8].
It is configured with multiple SVIs. One of the VLANs (VLAN 30) is a private VLAN with an associated isolated secondary VLAN (VLAN 31). Part of the config is as follows:
ip address 10.90.20.2 255.255.252.0
no ip redirects
no ip unreachables
no ip proxy-arp
private-vlan mapping 31
standby 30 ip 10.90.20.1
standby 30 priority 110
standby 30 preempt
switchport private-vlan host-association 30 31
switchport mode private-vlan host
no ip address
One particular IP address (10.90.23.180) has an ARP entry in the switch's ARP cache. But it's MAC address entry can't be found and the IP address can't be pinged. I believe this host is disconnected from the switch.
I understand if a host is removed from a port, its CAM entry is immediately removed. Question: What about its ARP entry (default aging time is 4 hrs)?
I executed the command "clear arp-cache". The ARP entry still exists. I then executed the command "clear ip arp 10.90.23.180"; the entry is removed.
Question: What's the difference between the commands "clear arp-cache" and "clear ip arp <ip_addr>"?
Please see attached file the commands I executed and their outputs.