topic arp in Network Security

arp

bluesea2010 — Sun, 30 Jan 2022 07:34:36 GMT

Hi,

How can I clear arp which is learned by outside interface only?. Because I am changing the router which is connected to outside interface

Thanks

Re: arp

balaji.bandi — Sun, 30 Jan 2022 07:40:46 GMT

We are not sure what is the Router and what Code running here - if you can give the information easy for us to assits here.

High level -

#show arp - give you how long the arp entry in the device.

# show arp x.x.x.x detail - give you more details.

#show interfaces x/x

ARP type: ARPA, ARP Timeout 04:00:00

depends on the device, some time it's 4 hours you can reduce by setting on the interface.

(config-if)#arp timeout ?
<0-2147483> Seconds

If you like to clear manually ARP entry :

#clear ip arp ?
A.B.C.D IP address of dynamic ARP entry
inspection Clear State of ARP Inspection
poll IP ARP host polling

Re: arp

Aref Alsouqi — Sun, 30 Jan 2022 11:14:47 GMT

The ARP table would automatically get cleared when you swap the routers connected to the outside interface. If that doesn't happen then probably the easiest way to get around this would be to shut/unshut the outside interface.