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Question about VNS Topologies: ARP Proxy & Multicast Filters

  • 27 September 2019
  • 3 replies
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Hi,

We have two Extreme C5210 wireless controllers running version 10.41.09.0008.
We have 1187 access points.
We are seeing quite a bit of ARP and mDNS traffic on our access points.
We have configured topologies for each of our VLANs.
We do not have VoIP devices on the wireless network.
There are users of streaming services such as Netflix and Amazon Prime, which I assume uses IPTV, on the wireless network.

There are two settings in the VNS topology that we think will help reduce this traffic. However, we want to fully understand the ramifications of making changes to two specific settings.

First, in the general tab of the VNS topology, you can enable ARP proxy. We figure that enabling ARP proxy will eliminate ARP request broadcasts on the wireless network. We assume this will be a good thing. Are there any caveats to enabling this feature? Are there any benefits to enabling this feature other than what I described above?



Secondly, in the Multicast Filters tab of the VNS topology, Multicast bridging is enabled. We assume that disabling Wireless Replication for mDNS/Bonjour, mDNSV6/Bonjour and WS-Discovery help eliminate the mDNS broadcasts. Again, we think this would be helpful. Are there any caveats of disabling Wireless Replication for these groups? Are there any other benefits to disabling this feature other than what I described above?



Thanks.

3 replies

Userlevel 5
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Hi Ken,

ARP Proxy is about AP responding on behalf of its connected MU. It helps a lot by making ARPs not wasting the airtime, good to have it enabled IMHO.
Multicasts are not enabled for wireless by default. What you have in the config, was configured at some point. Make sure certain multicast traffic (certain group) isn't needed and feel free to delete that group from the list then. If you don't need any Apple devices or Chromecasts etc. discovering themselves over wireless, you're good to go to get rid of those three.
Make sure to review the docs (https://www.extremenetworks.com/support/documentation/product-type/software/) and Extreme's knowledge base (https://gtacknowledge.extremenetworks.com/), sometimes they are really helpful in case of some issues. :)

Hope that helps,
Tomasz
Thanks Tomasz.
Userlevel 4
Fyi there is a pretty bad bug we ran into with arp proxy recently, so i would take this into consideration if you are going to enable it.

https://gtacknowledge.extremenetworks.com/articles/Solution/Apple-IOS-Bonjour-Sleep-Proxy-Claiming-Default-Gateway-IP-address

Extreme is working on a bug fix, but we had to disable it in the meantime in order to mitigate sporadic outages.

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