VLAN DHCP doesn't work with VLANID 2, but works with VLANID 21

VLAN DHCP doesn't work with VLANID 2, but works with VLANID 21

VLAN DHCP doesn't work with VLANID 2, but works with VLANID 21
VLAN DHCP doesn't work with VLANID 2, but works with VLANID 21
2 weeks ago - last edited 21 hours ago

I have five VLANs in my network. 1 is management, 10 is for a non-metered connection, 20 and 30 are for metered connections. I also have a fifth VLAN that is isolated from the internet, so I don't need to use any kind of AAA on it. The non-metered connection isn't always available, so I need to regulate how much internet everyone (around 500 people) use when we are on the metered connection. Omada's Local User accounts don't differentiate between internet data and data to the controller, so my admins need to be authenticated on the metered connection if I don't have a LAN Only network setup. Also, there's plenty of projects people have that don't use internet and can be on this LAN Only network, again without affecting any AAA.

 

That fifth VLAN doesn't assign IP addresses when I set it to VLAN 2. This is the one I'd like to set, because it just makes logical sense to me for the non-internet networks to be together, but when I do, everyone gets fall back IPs in the 169.254.XXX.XXX range on that network. When I set it to 21, it works fine. The only setting in the LAN configuration page that I change is the VLANID. Nothing else gets changed. IP range stays the same, DHCP stays the same, LAN interfaces stay the same, and I don't change any settings on any ports.

 

The only thing I can think of is maybe I need to restart the network hardware to refresh the port configuration profiles, but I've never had to do that in the past when changing VLANs. Request any ideas as to why this might be happening.

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Re:VLAN DHCP doesn't work with VLANID 2, but works with VLANID 21-Solution
a week ago - last edited 21 hours ago

  @BHJohnson 

 

Couple of questions, you mention VLANs 1, 10, 20, 30 and X.  Then you start describing VLAN2 and VLAN21, I can't make the math add up to 5 VLANs.  You haven't told us what gateway you are using or its firmware version, nor have you mentioned if you have ACLs set, which I'm sure you must, because those are required to isolate traffic.  I think it's important to look at the configuration of each of your VLANs, and also the ACL rules (and precedence). Are you using controllers?

 

Lastly, I have seen cases where a router is left in a confused state after certain configuration changes and a reboot or powercycle is required for the full config to come up and work properly.

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Re:VLAN DHCP doesn't work with VLANID 2, but works with VLANID 21-Solution
a week ago - last edited 21 hours ago

  @BHJohnson 

 

Couple of questions, you mention VLANs 1, 10, 20, 30 and X.  Then you start describing VLAN2 and VLAN21, I can't make the math add up to 5 VLANs.  You haven't told us what gateway you are using or its firmware version, nor have you mentioned if you have ACLs set, which I'm sure you must, because those are required to isolate traffic.  I think it's important to look at the configuration of each of your VLANs, and also the ACL rules (and precedence). Are you using controllers?

 

Lastly, I have seen cases where a router is left in a confused state after certain configuration changes and a reboot or powercycle is required for the full config to come up and work properly.

<< Paying it forward, one juicy problem at a time... >>
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