Sky Q - Network Packet Flood - SSDP Storm

[leomeow]

Hi All,

I've seen a number of discussions related to this in this forum and others on the Internet. Has Sky come up with a solution for this? or does someone knows of a good solution (when using managed switches - in my case Unifi)?

I've resorted to using Powerline Ethernet for the Sky boxes but in some cases, whatever SkyQ does, it brings that network down too.

Wifi on all Sky Q set to disable using the engineers menu.

Please help.

Many thanks.

[Leon0611]

Hi,

I've had a similar problem since early April 2025, maybe due to a firmware update pushed to the Q boxes (x1 main Q box and x3 Q minis).

All Q boxes on wired ethernet, bar 1.

Would normally get ~900Mbps download on wired laptop speed test (1G Internet). Since the Q upgrade getting ~300Mbps.

If I switch off all the Q boxes jumps back up to ~900Mbps.

Ran Wireshark on laptop and seeing all Q boxes flooding the LAN with SSDP packets.

Raised this with Sky tech support who ran some remote diagnostics and resorted to sending an engineer to my home. Engineer ran some diagnostics on iPad and said if I can get 300Mbps it's passed and nothing he can do.

Hoping Sky will fix this in next firmware. Not seen any other posts on this issue, yet.

[lettice]

@tarbat 

Do remember you had flooding on your Sky Q sometime back.

Anything you can help this customer with to further check or resolve.

All I would suggest in first instance, is a reboot of router and a reset of each of the Sky Q boxes 7a Der network, to see if it resets their connections.

Would have assumed the engineer visit would have done this though.

[cuke]

My Sky boxes are all wired, using MoCA devices through coaxial cables, and they have also the latest firmware. Seen no differences in the speeds of any wired or WiFi devices.

But using Netgear Orbi router through a 1Gbps Quickline fibre link, so could this be the difference?

[Chodley]

Similar to cuke here. I think the fact my Q is wired through a dumb 100Mb switch which is only connected to a powerline adapter (to reach the minis) and a mesh node (to get to the internet) is protecting the rest of my network from being spammed in a similar way. I think one of those two devices (or the fact it has wifi completely off perhaps) is saving my bacon but no idea how to figure out exactly what's happening.

[tarbat]

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@lettice wrote:

@tarbat 

Do remember you had flooding on your Sky Q sometime back.

Anything you can help this customer with to further check or resolve.

---

Yes, I remember. That was 4 years ago and caused by SSDP flooding the network and at the time only affected v3 boxes. The workaround at the time was to do the following:

The workaround to prevent the SSDP flooding DOS attack (only works if you have at least one minibox):
    1. On at least one minibox, set Standby mode to NONE. You can do more than one if you want.
    2. Make sure that this minibox is ALWAYS on - GREEN light. NEVER put this minibox into standby.
    3. Power-off reboot the main Sky Q box.

I thought this had been fixed in a previous update - QR16? But maybe it's got introduced again in a more recent firmware.

See previous thread at

https://helpforum.sky.com/t5/Archive/Sky-Q-v3-Q160-SSDP-Packet-Flooding/td-p/3734920

[leomeow]

I somehow found a post somewhere about setting STP priority values for each of the UNIFI managed switches.

Start with the main/parent at 0.

Sub/child at 4096.

Next sub/child at 8192 (example below).

This seems to localise whatever tantrum the Sky boxes are throwing and the network is running well  without any issues.

Hope this helps those on the UNIFI system.

[Chodley]

Very interesting. Googling a bit, that should prevent network loops so maybe what's happening is the sky box is not generating all the traffic, but rather the switches keep rebroadcasting some advertising packets that the sky box first broadcast? With the priority set like that I think the higher numbered devices (lower tiers in the tree) don't get to do that, the root one is "in charge"

[cuke]

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@Chodley wrote:

Very interesting. Googling a bit, that should prevent network loops so maybe what's happening is the sky box is not generating all the traffic, but rather the switches keep rebroadcasting some advertising packets that the sky box first broadcast? With the priority set like that I think the higher numbered devices (lower tiers in the tree) don't get to do that, the root one is "in charge"

---

Managed switches and SkyQ tend to produce this. If you search the community forum there will be several posts that come up.

[Leon0611]

Just an update from my previous post..

I switched off the main Sky Hub (SR203), main Q box and x3 minis. Download speeds went back up from ~300 Mbps to ~900Mbps from wired laptop.

Started turning on the Sky devices one-by-one, starting with Sky Hub to see if I could isolate the issue. With everything back on download stayed ~900Mbps.

So for me, may have just been a case of switching everything off and back on.

Still seeing the SSDP muticast floods from Q devices but doesn't seem to affect download speeds.

Q boxes still on Q300.000.06.00L (5yzv4ns) and on wifi as before.

Sky hub on 7.04.0100.R, not sure what it was on before.

[Chodley]

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@cuke wrote:

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@Chodley wrote:

Very interesting. Googling a bit, that should prevent network loops so maybe what's happening is the sky box is not generating all the traffic, but rather the switches keep rebroadcasting some advertising packets that the sky box first broadcast? With the priority set like that I think the higher numbered devices (lower tiers in the tree) don't get to do that, the root one is "in charge"

---

Managed switches and SkyQ tend to produce this. If you search the community forum there will be several posts that come up.

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Yeah I know, but ... why? 🙂 it seems to me this could be a root cause. Switches spam network by forwarding broadcast advertising packets from Q indiscriminately. Does there need to be more than one network device to cause this? Who knows. Cheap switches perhaps just kind of get confused, wifi signals maybe go wrong tenporarily. Managed switches perhaps detect the loop as they have stp support and they block ports and seem to not work? I dunno. It really annoys me that we don't know what these boxes are doing, it's not documented, and maybe 30-40% of the posts on here are the same issues over and over. When someone has the kit and skills to do some proper diagnosis like this it's very useful.