Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

gratuitous-arps

It appears (to me at least) that the documentation (Command References) and command lookup tool provide elusive/and almost contradict each other on what the default behavior is) for:

no ip gratuitous-arps

ip gratuitous-arps

On top of that it appears that Cisco does not support these

commands on certain IOS based Catalysts.

I thought (most likely incorrect) that 'ip gratuitous-arps' were enabled by default through 12.2?

12.3 on - no ip gratuitous-arps was the default

end of story.

Can someone please provide accurate information on this

or point me in the right direction?

Jim Abercromby

3 REPLIES

Re: gratuitous-arps

New Member

Re: gratuitous-arps

Let me make sure I have this straight

For IOS/Router platforms = 'ip gratuitous arps'

disabled by default since 12.2

For Catalyst/Switch (MLS) etc. = 'ip arp inspection'

This is disabled by default too.

So if I am looking to see if a catalyst switch is

filtering/restricting gratuitous arps

'ip arp inspection filter vlan' commands

filtering specific vlans would have to be configured.

YES or NO?

Re: gratuitous-arps

1. NO: For IOS/ROUTERS, by default, if no command is entered:

Gratuitous ARP messages are NOT sent out when the client receives the address from the local address pool.

2. YES for Catalyst, Dynamic Arp Inspection, not enabled by default

288
Views
0
Helpful
3
Replies