UPnP SSDP M-Search Broadcast

RonF

This might just be pilot error on my part, but I am seeing a behavior that I would like to stop.

I am watching packets going out of my home server, running Ubuntu 18.04, using Wireshark. About every 2 minutes, I see a broadcast to destination 239.255.255.250 port 1900; an SSDP M-Search * HTTP/1.1 packet. The SSDP payload contains a user-agent field with the value: Vivaldi/72.0.3626.82 Linux.

This caught me by surprise. I had created firewall rules that allow my server to open ports dynamically for a short period of time, using iptables and ipset, to allow my server's UPnP media server to find media renderers on my local network.

It appears now, that Vivaldi, (and probably any Chromium-based browser might do this,) is taking advantage of my use of ipset, and opening a port to receive SSDP Notify responses! I note that Firefox is not doing this, and I don't want Vivaldi to be doing it either. Is there any parameter I can set somewhere in Vivaldi to squash this?

I note that disabling IP broadcast for WebRTC is not relevant.

I don't know if this behavior is specific to Linux, or would occur with Vivaldi on other platforms as well. I think with some additional firewall rules, which I have not figured out yet, I can drop these undesired packets before they go out the Eth interface, but I would like to stop them at the source, if I knew how?

RonF

Using vivaldi://flags, I have disabled "Cast Streaming hardware video encoding" and "Connect to Cast devices on all IP devices" and according to Wireshark, Vivaldi is still periodically sending out a SSDP M-Search broadcast.

RonF

@RonF said in UPnP SSDP M-Search Broadcast:

Using vivaldi://flags, I have disabled "Cast Streaming hardware video encoding" and "Connect to Cast devices on all IP devices" and according to Wireshark, Vivaldi is still periodically sending out a SSDP M-Search broadcast.

Edit: I apologize, I meant I had disabled "Connect to Cast devices on all IP addresses."

RonF

Is the use of SSDP part of Chromecast support? If so, then disabling "Connect to Cast devices on all IP addresses" should have stopped these broadcasts. Is this then, a bug?

RonF

@RonF said in UPnP SSDP M-Search Broadcast:

Is the use of SSDP part of Chromecast support? If so, then disabling "Connect to Cast devices on all IP addresses" should have stopped these broadcasts. Is this then, a bug?

No response yet as to whether or not this behavior is a bug, but I can share the rule I added to my firewall to squash this broadcast being issued by the browser:

sudo iptables -I OUTPUT 4 -d 239.255.255.250/32 -p udp -m udp --dport 1900 -m string --algo kmp --string 'USER-AGENT' -j DROP