VLANS get IP by DHCP from default VLAN1 only! (RV130 router)

[bolhaskutya]

Hi Everyone,

I'm using the RV130 router.

• it is connected to the internet
• Ports 1-2 belong to office VLAN
• Ports 3-4 belong to guest VLAN
• Computers in separate VLANS dont see each other.

VLAN ID	Description	Port 1	Port 2	Port 3	Port 4
1	Default	Untagged	Untagged	Untagged	Untagged
3	VLAN-OFFICE	Tagged	Tagged	Excluded	Excluded
4	VLAN-GUEST	Excluded	Excluded	Tagged	Tagged

I wish that computers on one VLAN get ip addresses from 192.168.2.100 and so on.

The other VLAN 192.168.3.100 and so on. As they should.

DHCP is disabled for the default VLAN (id 1).

DHCP is configured properly for the other two VLANs.

Problem: All computers in both VLANS only get ip addresses 192.168.1.100 and so on.

Any suggestion is appreciated,

Paul

[jg.vink01]

Please share the config,  so we can check that.

Greetz,

Jeroen

[devils_advocate · Accepted solution]

If your hosts are plugged into the router directly then you need to ensure the ports are untagged in the relevant vlans, not tagged.

Tagged is only needed if you are plugging in devices which need to send tagged frames or are capable of processing them.

Try this:

VLAN ID	Description	Port 1	Port 2	Port 3	Port 4
1	Default	Excluded	Excluded	Excluded	Excluded
3	VLAN-OFFICE	Untagged	Untagged	Excluded	Excluded
4	VLAN-GUEST	Excluded	Excluded	Untagged	Untagged

User ports don't need to be a member (untagged) of Vlan 1, they need to be a member (untagged) of which Vlan you want them to be a part of.

[Prabath Godevithanage]

Here are few snapshots attached that i took someone else while helping out to assigned ports in to separate vlans.See if it is any help for you

[bolhaskutya]

Thank you! It works! I've been banging my head against the wall for 2 days. I was clearly going down the wrong road with tagging.

My working configuration is:

VLAN ID	Description	Port 1	Port 2	Port 3	Port 4
1	Default	Untagged	Untagged	Excluded	Excluded
3	VLAN-GUEST	Excluded	Excluded	Untagged	Untagged

• on Ports 1-2: all computers get IPs 192.168.1.100+
• on Ports 3-4 they get IPs 192.168.2.100+
• and they cant see each other.

Thank you very much! What a relief!

[devils_advocate]

You're welcome.

Tagging is only needed if that port needs to SEND tagged frames or RECEIVE them. 

Normal hosts (laptops, computers, printers etc) don't send tagged frames and cannot do much with them if they were to receive them. They send untagged frames and the switch uses the 'Untagged' Vlan ID that you configure to work out which VLAN the host is part of. 

Tagged is normally done between a switch and another switch or a switch and a server, although only if the server can tag frames which stuff like VMWare EsXi can. 

[bolhaskutya]

So for example I would need tagging, if I plug in a managable switch into one of the router's ports, that would have its own VLANs?

[devils_advocate]

Possibly.

So, you have two switches, Switch 1 and Switch 2.

Switch 1 is in a rack on Floor 1 of a building.

Switch 2 is in a rack on Floor 2 of the same building.

You have two Vlans: Guest and Business.

You create both the Guest and the Business vlan on both switches.

Say you have a Guest PC1 on Switch 1 which wants to communicate with a Guest PC2 on Switch 2.

Switch 1 and Switch 2 are connected together via a cable.

If Guest PC1 sends traffic to Guest PC2, the traffic needs to be sent across that cable from Switch 1 to Switch 2.

How does Switch 2 know what Vlan the traffic is part of? 

What if you also have a Business PC on Switch 1 and a Business PC on Switch 2 and then want to communicate?

When the traffic crosses the cable between the switches, how does either switch know what Vlan both sets of traffic belong to?

The answer is Vlan tagging.

Switch 1 tags the Guest Vlan traffic with the Guest VLAN ID.
It also tags the Business Vlan traffic with the Business VLAN ID.
Switch 2 does the same for traffic going the other way.

Basically if you want to connect two devices together (switch to switch, switch to router etc) and traffic for more than 1 vlan needs to be sent from one device to another, you need to use tagging so each side knows what vlan the traffic belongs to.

Hopefully that helps a little.

[intport1231]

Just a little comment though. By default OSs send its traffic untagged, but you can indeed configure the vlan tagging option in the specific host network adapter properties or in the Operating system (i.e windows registry).

So you could set the port to tagged if your source has already been configured to make use of vlan tags and you can even specify cos and tos options and give them more priority in the network element configuration.