topic Re: DHCP Issue on a wireless subnet via WLC 3504 in Wireless

DHCP Issue on a wireless subnet via WLC 3504

Kim131 — Thu, 25 Jan 2024 02:39:57 GMT

Hey guys,

I have a DHCP issue on one of the subnets 10.0.1.0/22. IP addresses are released well however only with IP addresses between 10.0.1.1-254 are able to access internet ( browse ) the rest of the users up to 10.0.3.254 cannot browse. tried to queries DNS records for a particular domain name using NSLOOPUP but still it is not working.

your assistance, please

Re: DHCP Issue on a wireless subnet via WLC 3504

RoadRunner4k — Wed, 24 Jan 2024 14:16:29 GMT

Which software are you running ? and is there an external DHCP handing out the IPs?

Is the mask correct on clients not able to access internet ?

Do you got a firewall / router infront to NAT users to internet ? then check if they allow the full subnet of /22

Re: DHCP Issue on a wireless subnet via WLC 3504

MHM Cisco World — Wed, 24 Jan 2024 17:16:28 GMT

90% of this issue is from the different mask between
1- GW interface
2- DHCP Pool
3- NAT list
this mismatch lead to this case
MHM

Re: DHCP Issue on a wireless subnet via WLC 3504

Haydn Andrews — Thu, 25 Jan 2024 03:04:37 GMT

Sounds like the subnet mask or the gateway is incorrect in the DHCP scope.

Or upstream firewall/ NAT rule has wrong mask for the subnet

Re: DHCP Issue on a wireless subnet via WLC 3504

Rich R — Thu, 25 Jan 2024 16:37:09 GMT

To add to the list of likely mistakes - wrong subnet mask in an ACL.

Re: DHCP Issue on a wireless subnet via WLC 3504

Kim131 — Sat, 27 Jan 2024 18:06:25 GMT

Hi Guys,

Thank you very much for your responses. it was the wrong subnet mask on the interface gateway on the firewall. It was /24 instead of /22.

Re: DHCP Issue on a wireless subnet via WLC 3504

MHM Cisco World — Sat, 27 Jan 2024 18:06:47 GMT

You are so welcome
MHM