topic Re: R610 Constant Arp Request in Access Points - Indoor and Outdoor

R610 Constant Arp Request

rob_m_istij3wx4 — Wed, 06 Nov 2019 22:40:48 GMT

I currently have a R610 and a R510. The R610 is the master and is hardwired with the R510 setup in a mesh configuration. I did a packet capture today and I noticed that the R610 kept arping for the gateway address. Is this normal activity? or is something not working correctly.
Thanks for the help!

See the screenshot below.

Re: R610 Constant Arp Request

michael_brado — Wed, 06 Nov 2019 22:42:24 GMT

Unleashed APs arp for the gateway, to determine if they have an Eth connection, or need to look to Mesh.

Re: R610 Constant Arp Request

rob_m_istij3wx4 — Wed, 06 Nov 2019 23:15:41 GMT

So this is normal only when the AP is setup to mesh? or all unleashed APs do this? Arping every 2 seconds for the gateway seems like a lot for an AP that is hardwired to a switch.

Re: R610 Constant Arp Request

albert_pierson — Wed, 06 Nov 2019 23:30:59 GMT

Hi Robert,

Mesh feature will send a unicast ARP (using MAC of GW for destination) every 30 seconds - this is required to verify if the AP is connected via the Ethernet port for automatic MESH mode ... if this ARP fails the AP will switch from Root (RAP) to MESH (MAP) ....

There may be other features in the AP that need to verify wired connectivity ... The AP does this for service state to bring down WLAN's if internet is not reachable, and perhaps also for MASTER auto select. These ARP's may be independent of the MESH mode test.

The AP may also have Proxy ARP enabled - where the AP responds to ARP requests from the network on behalf of the wireless clients - removing this ARP traffic from the RF network.

Check the destination MAC in the ARP requests ... this may help determine what type of ARP is occurring.

Hope this clarifies things.

Thanks

Re: R610 Constant Arp Request

rob_m_istij3wx4 — Thu, 07 Nov 2019 00:01:19 GMT

The ARP proxy is turned off on the AP. The MAC address for all the ARP request is the APs MAC itself.

Re: R610 Constant Arp Request

rob_m_istij3wx4 — Thu, 07 Nov 2019 00:02:27 GMT

The ARP proxy is turned off on the AP. The MAC address for all the ARP request is the APs MAC itself.

Re: R610 Constant Arp Request

rob_m_istij3wx4 — Thu, 07 Nov 2019 07:00:34 GMT

I check this again and tried resetting the AP. But no change. It is the same mac requesting the GW 24 times in 1 minute. That seems like a lot to insure it is online.

Re: R610 Constant Arp Request

albert_pierson — Thu, 07 Nov 2019 14:39:52 GMT

Hi Robert,

I did some additional research and found that the MESH wired network test using ARP is done every second. If 30 ARP requests to the Gateway fail then the AP will change MESH state, this is the 30 seconds I mentioned.

Yes this is a very aggressive test to make switching MESH state quickly enough to limit data loss when the wired network is no longer present.

I have not found any way to change this timer.

Sorry for the inconvenience this is causing.

Albert

Re: R610 Constant Arp Request

rob_m_istij3wx4 — Thu, 07 Nov 2019 14:47:10 GMT

Thank you so much for find out more about this! I started to figure that is probably the case, was to do an arp every second. I just wanted to ensure the AP was behaving correctly for the mode it is set up in.