OPNsense Forum

Archive => 18.1 Legacy Series => Topic started by: dcol on March 30, 2018, 12:31:13 am

Title: Multicast traffic
Post by: dcol on March 30, 2018, 12:31:13 am

What is generally the best practice for IGMP Multicast traffic. Allow or block on the internal networks?
I do see occasional hits from a WiFi router, which are now blocked with a default deny rule.

Title: Re: Multicast traffic
Post by: dcol on March 31, 2018, 08:17:34 pm

Bump, anyone.....

Title: Re: Multicast traffic
Post by: elektroinside on March 31, 2018, 09:54:50 pm

Allow on the local net :) It's actually a tool to improve network traffic in some cases.

Title: Re: Multicast traffic
Post by: dcol on March 31, 2018, 09:57:53 pm

That's what I thought. I will create a floating rule including all my internal interfaces, but not to WAN, to allow IGMP.
Thanks

Title: Re: Multicast traffic
Post by: elektroinside on March 31, 2018, 10:15:52 pm

You're welcome. Go ahead, although, just as a side note, in very secured setups, all (except the very minimum) TCP/IP processed stuff are disabled, including IGMP. And also worth mentioning that older OSs are vulnerable (regarding IGMP) but patches are available :)

Title: Re: Multicast traffic
Post by: mimugmail on April 01, 2018, 06:53:53 am

It only works in the local LAN if you don't use multicast routing (which is currently unsupported), so you can either create a rule for allowing or a rule for dropping with logging disabled.