Visitor

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5 Messages

11/10/2026 10:40 PM

Router advertisement frequency issue

I’m a residential Xfinity customer (gigabit service, Xfinity Gateway in bridge mode) in the Mountain region.

A 5-minute packet capture on my router’s WAN port shows IPv6 Router Advertisements arriving about every 1.7 seconds (171 in 300 s, median gap 1.68 s, max 3.81 s). I repeated the capture several times with similar results. They come from the router on Xfinity’s side of the line (the one that also answers as my IPv4 default gateway), not from my own equipment, and go to ff02::1. Router advertisements are normally sent every few minutes, so this is far more frequent than I’d expect.

It matters because my UniFi gateway pair (high availability) sends a sync update every ~3 seconds because of it, and Ubiquiti support has asked me to have Xfinity look at whether the interval can be reduced. I’ll try Xfinity support, but I’m usually on endless hold.

Two questions:

  1. Has anyone seen this, and did anyone get it fixed or find a contact who can adjust it?
  2. If you run your own router, could you check yours? tcpdump -ni <wan-interface> 'icmp6 and ip6[40]==134' shows the advertisements, and one every few minutes is normal.

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Official Employee

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3.2K Messages

1 day ago

Hi @user_ruv6y5, Thank you for visiting our official Xfinity Forums Community support page. Thank you for sharing the detailed packet capture data. While we understand how the frequent Router Advertisements are impacting your UniFi High Availability sync intervals, we are unable to modify the Router Advertisement broadcast interval on our network infrastructure. These intervals are standardized at the CMTS/gateway level to support residential service delivery and device discovery across our network, and they cannot be customized for individual accounts. We recommend reaching out to Ubiquiti support to see if any settings or workarounds can be found with no modifications being made from our end.

Visitor

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5 Messages

Thanks. Ubiquity is going to patch the bug, but they haven't provided a time frame.

Official Employee

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3.2K Messages

I am glad to hear that they are actively working on a patch. Hopefully it gets released sooner rather than later or in a beta firmware release before full release. Please let us know if there is anything more we could assist you with regarding the Xfinity account and services @user_ruv6y5. 

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