RT-AX88u igmp snooping issue on LAN5678

[Young Hoon]

Hi,

I'm using a asus router RT-AX88u with merlin firmware.

I got some issues with the condition on
1) wol enabled with desktop
2) IGMP snooping enabled (enable multicast routing)
3) IPTV connected to LAN 5 to 8 (5,6,7,8)


The issue is that, when the desktop is turned off and the lan card goes in to wol status with power efficient mode (10mbps), the intranet access (and of course internet access) becomes almost unaccessible. (very slow).
I guess that the issue is related to some bug on igmp snooping, because it is exactly same as that of when the switch does not support igmp snooping.
If I disable the connection speed reduction (power saving), than there is no issue.


I did tests with various firmwares including 386.x, 388.x, but the problem is remained.


My guess is that the igmp snooping does not function correctly for LAN port 5,6,7 and 8.
Because, the issue occurs only when WOL lan and IPTV are connected on LAN 5~8 both.


Some of my observations are as followings.

1. IPTV on one of LAN 5~8, and WOL lan on one of LAN 1~4 -> no issue.
2. IPTV on one of LAN 5~8, and WOL lan on one of LAN 5~8 -> issue.
3. IPTV on one of LAN 1~4, and WOL lan on one of LAN 1~4 -> no issue.
4. IPTV on one of LAN 1~4, and WOL lan on one of LAN 5~8 -> no issue.


I don't use any special functions on router, but I use following settings:
1) enable IGMP snooping
2) Choose IPTV STB Port None
3) link aggregation(LACP) enabled for LAN 1 and 2


Is there anyone who is on same situation as me? or, is this could be an issue related to merlin firms?

It would be great if I could get a solution to resolve the issue.

Thanks.

 

[drinkingbird]

Hi,

I'm using a asus router RT-AX88u with merlin firmware.

I got some issues with the condition on
1) wol enabled with desktop
2) IGMP snooping enabled (enable multicast routing)
3) IPTV connected to LAN 5 to 8 (5,6,7,8)


The issue is that, when the desktop is turned off and the lan card goes in to wol status with power efficient mode (10mbps), the intranet access (and of course internet access) becomes almost unaccessible. (very slow).
I guess that the issue is related to some bug on igmp snooping, because it is exactly same as that of when the switch does not support igmp snooping.
If I disable the connection speed reduction (power saving), than there is no issue.


I did tests with various firmwares including 386.x, 388.x, but the problem is remained.


My guess is that the igmp snooping does not function correctly for LAN port 5,6,7 and 8.
Because, the issue occurs only when WOL lan and IPTV are connected on LAN 5~8 both.


Some of my observations are as followings.

1. IPTV on one of LAN 5~8, and WOL lan on one of LAN 1~4 -> no issue.
2. IPTV on one of LAN 5~8, and WOL lan on one of LAN 5~8 -> issue.
3. IPTV on one of LAN 1~4, and WOL lan on one of LAN 1~4 -> no issue.
4. IPTV on one of LAN 1~4, and WOL lan on one of LAN 5~8 -> no issue.


I don't use any special functions on router, but I use following settings:
1) enable IGMP snooping
2) Choose IPTV STB Port None
3) link aggregation(LACP) enabled for LAN 1 and 2


Is there anyone who is on same situation as me? or, is this could be an issue related to merlin firms?

It would be great if I could get a solution to resolve the issue.

Thanks.

Ports 5-8 are known to be somewhat problematic on many models. You can get a cheap smart switch with multicast and igmp snooping support if you need more than 4 ports. You've probably stumbled across a combo that has issues on those extra 4 ports.

Did you try enabling fast leave to see if that makes any difference (if your model has that option)?

 

[Young Hoon]

Ports 5-8 are known to be somewhat problematic on many models. You can get a cheap smart switch with multicast and igmp snooping support if you need more than 4 ports. You've probably stumbled across a combo that has issues on those extra 4 ports.

Did you try enabling fast leave to see if that makes any difference (if your model has that option)?

I already enabled the fast leave option.

I have a netgear managed switch, but for some reason I have to re-construct the home network, and I found the issue during the reconstruction.

You’re right, if I can share my experience,
there was another issue when I was using rt-ac88u, another 8 port router..
But the difference was, the LAN 5-8 in rt-ac88u were realtek chipsets whereas 1-4 were broadcoms.

I could not expect the issue for rt-ax88u, because the spec sheets tell us that all ports are based on broadcoms..

 

[drinkingbird]

I already enabled the fast leave option.

I have a netgear managed switch, but for some reason I have to re-construct the home network, and I found the issue during the reconstruction.

You’re right, if I can share my experience,
there was another issue when I was using rt-ac88u, another 8 port router..
But the difference was, the LAN 5-8 in rt-ac88u were realtek chipsets whereas 1-4 were broadcoms.

I could not expect the issue for rt-ax88u, because the spec sheets tell us that all ports are based on broadcoms..

Yeah but it is likely "daisy chained" off the first switch which seems to cause issues. If you go into the CLI and look at the interfaces, you'll likely see that ports 1-4 are their own interfaces then port 5 covers the second switch (ports 5-8), which means it is the daisy chained design.

Have you tried with fast leave disabled also? With multicast on these routers/switches sometimes you just need to try a bunch of different combos and find which one works best. You could try without IGMP snooping also, technically it will mean excess traffic gets sent out ports that don't need it but it likely isn't a ton of traffic.

 

[sfx2000]

Ports 5-8 are known to be somewhat problematic on many models.

I agree - and on some devices, IGMP settings are also a setting over in the WiFi/Professional section which can be enabled (or not)...