T_X
So, the new fiber internet was supposed to be enabled last week. But the Fritz!box says: WAN connected, but no internet.
I then had a look with @wireshark: I'm seeing a lot of #ARP from ~2.5k fritz boxes, on #VLAN s 850 and 900. If I set these VLANs on my laptop I do get internet access. This does not look right to me.
As no support was available on Friday at 5pm anymore I left a message with my findings on our ISP's fault hotline, but haven't heard back yet.
Apr 12 at 11:10amWeb
Show threadT_X2d ago
Alternatively, does anyone know if it's possible to set a #VLAN on the WAN port of an #AVM #Fritzbox? FRITZ!Box 7690 in particular. And other than that it's plain ethernet with DHCP on the WAN port.
Show threadDon 🚫2d ago

@T_X I'm sure it can't.

The WAN port is intended for having another router / modem doing the dial in.

If you are looking for a fiber dial on, use the 5530/5590 fiber

Show threadT_X2d ago
@DonTheMaster that's what we have. There's a Genexis Fibertwist for the "modem" part, which converts the fiber(s) to RJ45 + coax for TV. The Fritz!Box provided by the ISP is a 7690, without an SFP slot. So supposedly the WAN port of the 7690 is to be connected to the LAN1 port of the fibertwist.
I would have preferred a passive instead of active termination. But got the active one due to some internal miscommunication on our side. But we should be able to switch to a passive one later for free.
Show threadT_X2d ago
Also, the ISPs #Schnittstellenbeschreibung does not mention any #VLAN s. So I'm quite certain that they messed up their VLAN config. :D
Show threadJohann2d ago

@T_X

The FritzBox has a setting for a VLAN Tag. Normally, it tries this automagically with some common VLANs.

But seeing ARPs from 2,5k other boxes seems odd and at least shows a bad network design.

Show threadneocturne2d ago
@T_X Did they accidentally plug you into a trunk/uplink port xD
Show threadT_X2d ago
@neocturne it kind of looks like it. I don't dare to validate that in practice though :D. But with all this ARP, I could imagine that one could do quite some mischief with/like that. I would be kind of curious to see the initial reaction of the person listening to the recorded message I left on their fault hotline. :D
Show threadT_X2d ago
@neocturne also, yes, we are installing our own fiber, too. But not *that* much fiber to be a viable upstream :D.