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Clearing single arp entry in 6500 switch

ullasupendran
Level 1
Level 1

Is there any way to clear a single ARP cache entry on the 6500 switch ?

Thanks in advance

Ullas

8 Replies 8

Roberto Salazar
Level 8
Level 8

Nope there is no way to clear a single ip, I don;t think you can clear a single ip on any platform:

c6509-E#clear arp 1.1.1.1

^

% Invalid input detected at '^' marker.

c6509-E#clear arp ?

Hello,

I see on C6500 with Supt 720 3B that is possible to clear the entries associated with a single L3 interface:

clear arp interface Vlan ?

<1-4094> Vlan interface number

Hope to help

Giuseppe

Hi guiseppe

Unfortunatly mine is sup II (c6sup2_rp Software (c6sup2_rp-JK2SV-M), Version 12.1(22)E2 ).

I could nt find that command in the switch.

6513-A#clear arp ?

Ullas

Elly Bornstein
Cisco Employee
Cisco Employee

No there is not a way, but just FYI.

Clearing ARP cache is not really 'clearing' it.

when you clear ARP cache you are sending a bunch of unicast ARP requests to every host in your ARP table, if they reply we refresh the ARP entry. If no reply then we clear out the ARP entry.

If you want to just refresh an ARP entry for a particular host, just ping it.

Does that mean if i do a clear arp-cache , will it affect any existing connections?

Ullas

'clear ip arp A.B.C.D' where A.B.C.D is the IP address.

I have a Sup2 and I can only clear arp completely or by interface

HTH, John *** Please rate all useful posts ***

What version of IOS are you running on the Sup2? I ran this on newer Sup720-10G and Sup720-3B modules running newer SXJ code and on a Sup720-3B running older SXF. Not sure without combing through release notes whether it's hardware or IOS version dependent.

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