Does the RT-AX86U support WAN and LAN on the same port?

[Qbcd]

Here's the situation, I have a modem and a managed switch (supporting VLANs) in a network cabinet and then an RT-AX86U router in a different room and only one Cat6 cable connecting the two areas. I really can't have the router in the same place as the modem and switch.

So what I want to do is connect the modem to the switch, and then have another run from the switch to the router. That would be VLAN 1 (WAN). But the switch also has wireless access points connected to it, so I want those to be on a VLAN 2 (LAN), but they'll have to share a cable to the router's WAN port. And then the router itself has a PC connected to its built-in LAN port.

Here's a crude diagram of the setup:

My question is, can the RT-AX86U accept WAN and LAN from one of its ports, and know to keep them separate? Using stock firmware? How would I set that up?

Thank you.

 

[ColinTaylor]

No, that configuration is not possible. The closest you could get would be to put another managed switch next to the RT-AX86U. Then plug the WAN and one LAN port into the switch. Tag each of those ports with different VIDs and create a trunk between the two switches.

 

[Qbcd]

No, that configuration is not possible. The closest you could get would be to put another managed switch next to the RT-AX86U. Then plug the WAN and one LAN port into the switch. Tag each of those ports with different VIDs and create a trunk between the two switches.

I see, thanks. That's doable, managed gigabit switches are cheap enough, I can get another one and keep it under the router.

Just curious, do you mean it's not possible in general or not possible with this router? It should be possible if the router is smart enough to do it. I would have thought an expensive router like the RT-AX86U would have that functionality, I mean isn't it all software?

 

[ColinTaylor]

Just curious, do you mean it's not possible in general or not possible with this router? It should be possible if the router is smart enough to do it. I would have thought an expensive router like the RT-AX86U would have that functionality, I mean isn't it all software?

It's not possible with this router. It doesn't support VLANs, other than for IPTV which is a special case.

 

[Qbcd]

It's not possible with this router. It doesn't support VLANs, other than for IPTV which is a special case.

I see, thanks. I keep discovering all the things this router does not support, for a $250 router you'd think it would have more advanced features. Just curious, do you know what the cheapest Asus router is that supports VLANs?

 

[ColinTaylor]

I see, thanks. I keep discovering all the things this router does not support, for a $250 router you'd think it would have more advanced features. Just curious, do you know what the cheapest Asus router is that supports VLANs?

Asus routers don't support VLANs. That said.... there was a beta firmware just released for the new RT-AX86_Pro (and some other model IIRC) that adds VLAN support for the first time. Search the forum for that discussion. But I suspect that would be VLANs on the LAN side, not the WAN side. I can't remember the details.

 

[Tech9]

for a $250 router

This AIO device is actually pretty cheap for Raspberry Pi like Router + 5-port Switch with 2.5GbE port + Wi-Fi 6 Access Point. The functions you need are not available in home routers. From what's available you'll be surprised how many other things don't work exactly as expected or don't work at all.

The configuration above is called router on a stick. For this to work you need configured managed switch and a router/firewall with WAN and LAN logical interfaces on single physical interface. If the physical connection is Gigabit you'll be limited to 1/2 throughput for WAN and LAN. I was running pfSense on a single NIC mini PC this way for about a year with physical WAN on a Netgear managed switch. You need something better than home router.

 

[Qbcd]

Asus routers don't support VLANs. That said.... there was a beta firmware just released for the new RT-AX86_Pro (and some other model IIRC) that adds VLAN support for the first time. Search the forum for that discussion. But I suspect that would be VLANs on the LAN side, not the WAN side. I can't remember the details.

Thanks. I wasn't even aware of the Pro's existence. Seems like it's almost the same hardware-wise, so it makes sense they want to differentiate it with software... I think the LAN ports can be used for WAN as well, so if they implement VLAN on the LAN ports, you could theoretically set up two VLANs and run the WAN on one and LAN on the other...? Anyway, I hope they figure it out. I would upgrade to a more expensive router like the AX6000 if it had that feature, I hope they will roll out the update to other routers as well (probably not to the plain AX86U though).

 

[Qbcd]

This AIO device is actually pretty cheap for Raspberry Pi like Router + 5-port Switch with 2.5GbE port + Wi-Fi 6 Access Point. The functions you need are not available in home routers. From what's available you'll be surprised how many other things don't work exactly as expected or don't work at all.

The configuration above is called router on a stick. For this to work you need configured managed switch and a router/firewall with WAN and LAN logical interfaces on single physical interface. If the physical connection is Gigabit you'll be limited to 1/2 throughput for WAN and LAN. I was running pfSense on a single NIC mini PC this way for about a year with physical WAN on a Netgear managed switch. You need something better than home router.

Interesting, thanks. I think the solution with 2 managed switches is easy and cheap enough. Are you saying bandwidth is always split 50/50, not dynamically allocated according to need? That is to say, WAN and LAN will always be limited to 500 mbps no matter what? If so, I may get managed switches with 2.5G ports, then I would get 1.25 gbps for each.

Edit: Damn, checked prices and managed switches with 2.5G ports are WAY more expensive than gigabit switches. You can get a managed 8-port gigabit switch for £28. The cheapest I found that has 2.5G ports (only two, not all of them) is a Zyxel for £175, and honestly not my favorite brand. Could anyone recommend a managed switch with 8 ports, needs just one 2.5G for the trunk line, for around $100 or less if that exists? It has to be relatively compact and quiet though, not a server part.

 

[ColinTaylor]

Interesting, thanks. I think the solution with 2 managed switches is easy and cheap enough. Are you saying bandwidth is always split 50/50, not dynamically allocated according to need? That is to say, WAN and LAN will always be limited to 500 mbps no matter what? If so, I may get managed switches with 2.5G ports, then I would get 1.25 gbps for each.

No the bandwidth would not be split 50/50. It would be dynamic up to an aggregate throughput of 1Gb in each direction as Gigabit Ethernet is full duplex. That said, you might want to setup some QoS on the switches if you're going to be saturating the trunk.

 

[Qbcd]

No the bandwidth would not be split 50/50. It would be dynamic up to an aggregate throughput of 1Gb in each direction as Gigabit Ethernet is full duplex. That said, you might want to setup some QoS on the switches if you're going to be saturating the trunk.

Great, thanks. So if I understand correctly, with a gigabit internet connection, if someone connected to the switch near the modem in the diagram were to run a speed test they would at most get ~500 mbps because you'd have 500 mbps going into the router over the trunk and then back to the client over the same trunk.

But if I'm using the PC in the diagram, then I can get the full gigabit because the trunk is only used for WAN in that scenario.

All correct?

And you'd need 2.5G trunk ports on both switches to be able to properly saturate a gigabit connection across the entire network.

 

[ColinTaylor]

That would be my expectation. As with everything there might be certain peculiarities specific to the equipment you're using so YMMV. You might need to tweak the QoS rules, perhaps to prioritise the WAN VLAN.

 

[Qbcd]

So is there such a thing as an 8 port managed switch with a single 2.5G port at a reasonable price? It's like the cheapest managed switch I can find that has any ports faster than 1G starts at 5 times the price of the 1G-only equivalent, it's crazy.

 

[crusey_aus]

Why cant you just get a second ethernet cable installed between router and switch ?

 

[Qbcd]

Why cant you just get a second ethernet cable installed between router and switch ?

If I could, I wouldn't have asked the question.

However, I just realized that there is a coax run between the two locations as well, so I could use Moca for the LAN. May be cheaper and simpler.