Clearing ARP Tables in a Standard Cisco

From KoshWiki

Contents 1 Description 2 Clearing the ARP Cache 2.1 Clearing The Entire ARP Table: or how I learned to love the bomb 2.2 Clearing a single IP Address from the Table: Surgical Strike 3 References

Description

Clearing ARP Tables in a Cisco is an annoyingly easy task, but if you can't remember the command. This is for you.

Mostly extracted from the Cisco Guide^[1]

Clearing the ARP Cache

There are two methods, the easy nuclear way, and the easy scalpel way.

Clearing The Entire ARP Table: or how I learned to love the bomb

NOTE: this will most likely drop all connections going through your cisco.

#clear arp-cache

Clearing a single IP Address from the Table: Surgical Strike

First check the status of the IP, this is just so you have a point to start from

#show arp | include 127.0.0.1
Internet  127.0.0.1          95   001f.9227.87e5  ARPA   Vlan1

Names have been changed to protect the guilty.

Then flush the IP addresses record.

#clear ip arp 127.0.0.1

Then check your handy work, of course this didn't change for me, because i'm just flushing a random.

#show arp | include 127.0.0.1
Internet  127.0.0.1          95   001f.9227.87e5  ARPA   Vlan1

Congratulations, you can now fix or frell ARP caches on a cisco.

References

1. ↑ Cisco IP Addressing Commands for IOS 11.3