AP to traffic

Sorry, I mean AP no traffic.

Hi,

does your new switch do any routing or VLANs?

Ian

No routing (runs SwOS) but VLANs yes, actually the APs are on a separate VLAN. Because the Mikrotik switch has optical ports I connected one AP to the management port (set to the right VLAN for AP) and also to another access switch connected optically to the 317 and got no traffic. This access switch, if connected somewhere else, permits traffic from the AP. And again the AP itself works just fine with or without the Mikrotik 317.

Hi,

what you are saying points to a switch configuration issue/s. Are your APs VLAN enabled or just connected to a seperate VLAN?

Ian

The APs are not configured for a specific VLAN, the switches put them on the same VLAN.

Please provide a network drawing showing VLANs and how APs are connected.

Ian

After debugging with a laptop, I saw that actually some traffic passes. So I played with ping of different packet sizes. It worked till 1410, so I went to XG and changed the MTU of the WiFi interface, but then the ping worked till another size, less than 1410. Also worked for a while the HTTP protocol but not HTTPS. It's obvious a MTU problem but it is not easy to replay.

What you are pointing at is the switch MTU being wrong.

Ian

Hello chrysmon,

Could you please check if you could change the MTU settings on your switch? Ideally it is set to 1500 but Vlan takes the (1500 bytes data + 4 bytes VLAN header + 14 bytes Ethernet header). So reducing the MTU value on switch i..e1496 or1482 can be checked.

Hello chrysmon,

Could you please check if you could change the MTU settings on your switch? Ideally it is set to 1500 but Vlan takes the (1500 bytes data + 4 bytes VLAN header + 14 bytes Ethernet header). So reducing the MTU value on switch i..e1496 or1482 can be checked.

I cannot change the MTU on the switch, only on XG's network card where the ACs are connected. It is actually 1500. I made a lot of changes without any success.

The maximum ping packet size to the ISP is 1418, anything bigger cannot pass.

Hello chrysmo,

I am not sure if this could sort out the issue, but you may go give it a try.

I finally booted the RouterOS, setup as switch with VLANs, and worked fine, without any other fine tuning. So most probably there is a bug in SwOS of Mikrotik. Anyway there is no XG issue, nor any way to resolve it from Sophos hardware and software.