DHCP Issues with vLANS

GaryShainberg
Building a reputation

DHCP Issues with vLANS

Friends,

 

I have spent the evening trying to solve this problem and got nowhere.

 

I am having some very odd DHCP issues, I created a new vLAN and then a new SSID and configured it to use the vLAN but when a device connects its not being served a DHCP address.

 

I have done this hundreds if not thousands of times and even though I am tired and often (in the past) missed the obvious, this time I have tried to eliminate each bit of the set-up but still can not see what it's not working.

 

I was just wondering if anyone else has seen an issue like this in the last couple of days, just in case its a firmware or dashboard issue.

 

I am off to bed now but would appreciate any overnight thoughts

 

TIA

 

 

CTO & Solutioneer
CMNA, CMNO, ECMS2
SNSA, SNSP
~~If you found this post helpful, please give it kudos. If my answer solved your problem, click "accept as solution" so that others can benefit from it.~~
8 REPLIES 8
UCcert
Kind of a big deal

Look at it again in the morning with fresh eyes. Strip it back to the bare bones and start again methodically 

Darren O'Connor | uccert.co.uk
https://www.linkedin.com/in/darrenoconnor/

I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.
rbnielsen
Head in the Cloud

Is the vlan trunked all the way out to the AP?
The vlan is being tagged on the switchport?
LinkedIn ::: https://blog.rhbirkelund.dk/

Like what you see? - Give a Kudo ## Did it answer your question? - Mark it as a Solution 🙂
GaryShainberg
Building a reputation

Guys

 

Thanks, the network already has a number of ssids with vlans associated to them and the switch-ports are all set to trunk.

 

It's actually my own network so it's quite mature and been working fine.

 

I will start again today, having stripped back as much as I can, but I also have a lab/reference platform that I can test it on.

 

That said, I have been playing with this kit for a long time and in a LBC (Life before Corona) would normally be setting this type of access up monthly for external events, so I am not sure what is occurring, but I WILL get to the bottom of it.

 

 

 

 

 

CTO & Solutioneer
CMNA, CMNO, ECMS2
SNSA, SNSP
~~If you found this post helpful, please give it kudos. If my answer solved your problem, click "accept as solution" so that others can benefit from it.~~
DJDonovan
Meraki Alumni (Retired)

Hi Gary!

 

For the AP that you were testing the connection on, what is the switch port configuration for the port the AP is cabled into? Also, do you have Client IP assignment set to Bridge Mode or NAT mode on the SSID? If you could include a screenshot of the VLAN configuration for the SSID that would also be appreciated. 

 

Thanks!

-Donovan

~~If you found this post helpful, please give it kudos. If my answer solved your problem, click "accept as solution" so that others can benefit from it.~~

The Meraki ECMS exam is now live! Test your knowledge of Meraki and become an official Cisco Meraki Solutions Specialist. More info on the ECMS exam found here.

For information regarding all of Meraki's training offerings, be sure to check out the Meraki Learning Hub.
GaryShainberg
Building a reputation

@DJDonovan ,

 

Thanks for the thoughts, the issue appears to be network-wide on multiple AP's, they are all connected to switch ports that are set to trunk mode.

 

As I mentioned in the original post, I have set this solution/set-up many times before as its part of my business, which is why I am very confused. Its as though DHCP is being blocked but I have checked the switch settings and DHCP servers are not being blocked.

 

I do have an ACL in place for another vLAN, which I have just deleted so will try again and see what happens.

 

Any other thoughts as to what could / would block dhcp would be appreciated..

 

TIA

 

-Gary

 

 

 

CTO & Solutioneer
CMNA, CMNO, ECMS2
SNSA, SNSP
~~If you found this post helpful, please give it kudos. If my answer solved your problem, click "accept as solution" so that others can benefit from it.~~
DJDonovan
Meraki Alumni (Retired)

@GaryShainberg 

What is the Native VLAN of the trunk ports they're cabled into, and what VLAN are you placing this SSID on? I'd recommend doing packet captures on the AP, switch, and DHCP server port to see what's happening to the clients DHCP discovers. That's going to be the quickest way to narrow down where the issue is occurring.

-Donovan

~~If you found this post helpful, please give it kudos. If my answer solved your problem, click "accept as solution" so that others can benefit from it.~~

The Meraki ECMS exam is now live! Test your knowledge of Meraki and become an official Cisco Meraki Solutions Specialist. More info on the ECMS exam found here.

For information regarding all of Meraki's training offerings, be sure to check out the Meraki Learning Hub.
GaryShainberg
Building a reputation

@DJDonovan the native vlan is 1 and I have tried a number of different vlans but for now I am trying 111, I will try a capture in the morning.

 

Thanks

 

 

CTO & Solutioneer
CMNA, CMNO, ECMS2
SNSA, SNSP
~~If you found this post helpful, please give it kudos. If my answer solved your problem, click "accept as solution" so that others can benefit from it.~~

I would probably also consider doing a hard reset on the MX..
LinkedIn ::: https://blog.rhbirkelund.dk/

Like what you see? - Give a Kudo ## Did it answer your question? - Mark it as a Solution 🙂
Get notified when there are additional replies to this discussion.
Welcome to the Meraki Community!
To start contributing, simply sign in with your Cisco account. If you don't yet have a Cisco account, you can sign up.
Labels