topic Re: MSM430 - constantly sends ARP gratuitous packets in M and MSM Series

MSM430 - constantly sends ARP gratuitous packets

DSV12 — Sun, 20 Oct 2013 12:20:13 GMT

Hi, all!

We started the deployment of a wireless network based on MSM765zl controller and MSM430 AP's. Firmware version latest at this moment (6.0.1). Now only runs two first AP's and one constantly sends ARP gratuitous packets (request to own IP) with rate ~5-8 packs/sec. Why is this happening and how to fix that?

TIA,

DSV

Re: MSM430 - constantly sends ARP gratuitous packets

DSV12 — Mon, 21 Oct 2013 13:00:03 GMT

@DSV12 wrote:
Now only runs two first AP's and one constantly sends ARP gratuitous packets (request to own IP) with rate ~5-8 packs/sec.
Very interesting continuation: after switching on the third AP, it started sending ARP gratuitous packets. And AP2 cease to send ARP after few minutes. If I turn off AP3 then AP2 begin to send ARP gratuitous packets again. Seems that ARP packets continuously sends only last discovered (and turned on) AP.

Re: MSM430 - constantly sends ARP gratuitous packets

MSMenthousiast — Wed, 11 Dec 2013 13:45:54 GMT

I guess you are using the Intrusion Detection System? If so, then it is normal behavior.

Re: MSM430 - constantly sends ARP gratuitous packets

Z273 — Fri, 20 Dec 2013 17:16:47 GMT

IDS is sending ARP gratuitous to detect rogueAP.

One AP is elected to send those ARP over the LAN, APs which have clients associated will bridge those ARP to the wifi.

If a rogueAP is connected to your LAN and there is client associated, this AP also floods ARP to the air, those ARP will be seen by legit APs and the bssid of the rogueAP is compared against a list of "legit" AP.

Hope that is clear.

To disable those ARP, sadly you have to disable IDS.

Maybe the rate at which those ARP are sent should be configurable.

Re: MSM430 - constantly sends ARP gratuitous packets

Arimo — Mon, 30 Dec 2013 14:47:11 GMT

One thing to add.

If you want to use 6.x FW, I'd recommend going to 6.2 or contacting support for 6.0.1.3-Sr1. Check the release notes for fix list.

Controller release notes:

https://h10145.www1.hp.com/downloads/SoftwareReleases.aspx?ProductNumber=J9694A

AP FW release notes:

https://h10145.www1.hp.com/downloads/SoftwareReleases.aspx?ProductNumber=J9651A