Dump AP - IP assignment no more working after enabling IGMP snooping

Installing and Using OpenWrt
1

Hey Guys,
yesterday I've installed my https://openwrt.org/toh/gl.inet/gl-mt6000 with latest OpenWRT + opkg updates.
Since I had problems with Spotify Connect in between VLANs I've played around with enabling "IGMP spooping" on the bridge device of my dump AP (with no DHCP enabled).

When IGMP spooping is activated my WLAN clients do net get an IP address from the external DHCP (OPNsense) assigned. When I disable it again its working.

I tried it several times and it is reproducible.

Is that a bug or feature?

OpenWrt 23.05.5 r24106-10cc5fcd00 / LuCI openwrt-23.05 branch git-24.312.02817-694e48d on GL-MT6000

Clients (Android 9, 13, WLAN Radio).

2

Upgrading packages (via the CLI opkg upgrade command or the LuCI Upgrade... button) can result in major problems. It is generally highly discouraged, unless you know what you are doing or if there is specific instruction to do so.

I'd say neither.... it's very likely an incorrect use of the IGMP snooping option, so it's potentially doing what is expected.

IGMP Snooping is not typically needed in normal home networks.

3

yeah, I already learned that opkg upgrade should not be used (right after I did it I found the warning in the forum) :slight_smile:

But should IGMP snooping really have influence on DHCP?

4

IGMP snooping is usually used on managed switches that handle a lot of local traffic (often to ensure that the uplink port doesn't become saturated). It's not really necessary for simple bridged APs and the like.

I've never experimented with the feature on an AP, though, so I don't know what it will do with DHCP traffic from the main router to downstream WiFi clients.

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