no ip arp gratuitous

[Alacran]

Hello All,

I have a question about the command no ip arp gratuitous.

Why, on some equipment (C2960 for example), this command should be apply on global configuration and on other equipment, we should apply it on each interface?

Sub question: I need to apply this command only on ip interfaces. So, on C2960, if I can only apply on global configuration, it will not work. Correct?

Thank you.

[Reza Sharifi]

Hi,

Arp is used to associating a hardware address with an IP address on the local network. Enabling it on a layer-2 switch globally should have no impact.

HTH

[Alacran]

Hi,

Thank you for your answer.

I known that arp is for IP interfaces.

Maybe I misspoken myself.

On some equipments, I can apply this command only on few IP interfaces. If I do not want to apply it on an IP interface, I can.

On the C2960, I am forced to apply it on the global configuration. If I want, I can not discriminate IP interface.

Is the result the same?

Why do some equipments work differently with their configuration mode?

[paul driver]

Hello

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@Alacran wrote:

Hello All,

I have a question about the command no ip arp gratuitous.

Why, on some equipment (C2960 for example), this command should be apply on global configuration and on other equipment, we should apply it on each interface?

Sub question: I need to apply this command only on ip interfaces. So, on C2960, if I can only apply on global configuration, it will not work. Correct?

Thank you.

---

My understanding -I guess you don't have to, it all depends if you wish to have it enabled for all  interfaces, If so, then you would or could apply is globally which personally isn't as deterministic than applying it specific to an interface, Also having it enabled globally opens up the device to be susceptible to MIM attacks.

Allowing GARP on specific interfaces can limit such attacks and can be useful on FHRP interfaces to update the arp table in case for failover.

res
Paul