What's new

Multiple ISPs, GS108TP - VLAN setup to allow dhcp

  • SNBForums Code of Conduct

    SNBForums is a community for everyone, no matter what their level of experience.

    Please be tolerant and patient of others, especially newcomers. We are all here to share and learn!

    The rules are simple: Be patient, be nice, be helpful or be gone!

canuck in the wilderness

Occasional Visitor
I live in the great wilderness of Canada - my internet would be nonexistent except for my radio connections (Ubiquiti) which bring me signal from 25 km (15 mi) away. This introduces a few issues.

I have one radio connection to my modem in town; I pull 2 static addresses to two routers without a problem. One manages the radios only, but also has a public address for when I'm away from home; the other is my internal network at home. Home router (Asus N66U) supplies dhcp to internal devices.

(I also have a s-l-o-w backup ISP in case my main internet goes down - not an issue at the moment.)

My main ISP supplies several dhcp addresses as well if I want them. Today I got a new Asus AC68U and wanted to test it, thinking that I can grab a dynamic address. Up until now all connections were running through a dumb d-link unmanaged switch ("modem/radios" >> routers 1 & 2 and various devices).

Plugging in the 68U it simply grabs an address from the 66U - clearly not what I want.

Unplugging the LAN connection from the 66U > switch to prevent the dhcp reaching the 68U, I still can't pull a dynamic address at all from the ISP in the 68U - which surprised me as it is all still connected to the modem via the radio link. [Logic says that if a static router can pull its address from the same configuration/wiring, I should be able to get a dhcp address, too. Apparently logic is wrong.]

So I set up the GS108TP - first as a dumb switch - same result. I then tried to create, using the reference guides on SNB here, three VLANs:

VLAN 10 - Internet: untagged - all ports (modem/radios connected to port 1)
VLAN 20: static routers - untagged - all ports except #3 (blank) - to prevent dhcp from 66U > 68U; both static routers and all internal devices connected here
VLAN 30: dchp routers - untagged - only ports 1 and 3 (68U attached on port 3)

Still no joy on pulling a dhcp address to the 68U on port 3 and worse: ALL LEDs started blinking simultaneously. I have no idea why they would do that.

Clearly I'm missing something (or a lot!) - can anyone suggest how to get this to work?
 
Can you draw out how your network currently operates?
Its a little hard to follow based on the description.
Also, what is the subnet mask you get from your ISP on DHCP?
should be something like 255.255.255.248
 
Thanks Cloud200 -

All of the existing network is shown in the attached diagram in black, and all works as I want.

The "radio management PC" is just used for taking care of the radios, but does have internet access for grabbing updates and similar tasks. Other than that I don't use it at all.

Both routers have public static addresses (forgot to show that on the N66U). The General PC is used, occasionally, for direct connections to the radios/radio PC, but this is disposable if need be.

New/desired items are in red. I want to insert the AC68U into the mix, but I only have 2 static addresses from Shaw. I have another 5 dynamic ones. However - if I insert the 68U as shown, it picks up a dhcp address in the .114.x subnet - but not a public one. Even if I disconnect the 68U LAN / Switch cable I can't seem to get a dynamic public address (tried with a PC and the router).

Weirdly, I accidentally set my 66U to dual WAN and the secondary WAN picked up a Shaw dynamic address - at the price eventually, of blowing my static ones. Reboot modem time. :-(

I'd also like (eventually) to be able to have a VoIP phone on its own VLAN but that is definitely a "wish" not a need. It works spectacularly poorly at the moment and I hoped that isolating its traffic might help.

The big issue seems to be getting the AC68U away from the dhcp of the N66U. (Eventually the 68U will take over all the stuff that is on the 66U's portion of the network, hopefully speeding up my media connections.)

My thought was that VLANs would segregate the two routers so my public addresses are OK, and some of the other traffic, to provide a little better throughput internally and externally.
 

Attachments

  • net diag - wish.png
    net diag - wish.png
    201.5 KB · Views: 441
OK I understand what you want now.
Here's how to do it with minimal fuss;
Port 1 : Radio uplink
Port 2 : E1200 WAN
Port 3 : E1200 LAN 1
Port 4 : Radio Man PC
Port 5 : Asus 68U WAN
Port 6 : Asus 66U WAN
Port 7 : Asus 66U LAN 1
Port 8 : LAN device (192.168.114.x subnet)

For port based VLANs:
VLAN10: 1, 2, 3, 4, 5, 6
VLAN20: 1, 2
VLAN30: 1, 3, 4
VLAN40: 1, 5
VLAN50: 1, 6
VLAN60: 7, 8

Red Xs are the PVID VLAN to be set on that port
Capture.PNG

Once we can confirm this all works . . . we can tighten it up a bit.

Edit:
I forgot the PVIDs
 
Last edited:
That worked!! Thank you soooo much - I really appreciate it. I did manage to lock myself out the first time around as I forgot to manage my location with respect to the Management VLAN. Oops. Made it VLAN 60 and made sure I was on the right port when I did the second go-around.

I can confirm that the locations that should be able to talk to each other can - and the ones that shouldn't can't, and that the new router picked up a public dhcp address.

Now I have to understand the logic in order to do the next two things I guess:
- add another switch and uplink to it
- figure out if it's possible to segregate my VoIP traffic so I can use that phone more reliably

(I assume that none of the routers which are dhcp servers can send an IP "back"down the "radio" line though I'm not quite sure why...but perhaps when I understand the logic that will make sense.)
 
To help this make this make sense to you;
PVID is what the switch will tag traffic coming in from that port on a VLAN.
The VLAN being Untagged is what allows traffic to flow from that VLAN out to the device attached to the port.
 

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top