R610 Constant Arp Request

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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.
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Robert Miller

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Posted 4 weeks ago

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Michael Brado, Official Rep

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

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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.
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Albert Pierson, Employee

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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
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Robert Miller

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

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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. 
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Albert Pierson, Employee

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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
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Robert Miller

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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.