DHCP connection Failures

[BenConroy]

Hi There,

We're currently experiencing some issues with a high number of DHCP connection failures reported on our AP's in our VSZ. For some context, we are a K-12 school with 15 seperate buildings. There is a subnet for each building which means 16 in total plus management. This was historically set-up before I began my role here.

We have our DHCP lease times on these from anywhere between 1 hour to 4 hours depending on the traffic that area of the grounds experiences. This has been tweaked over time as needed based on experience. Again, this was setup before I got here.

We have around 1100 clients connected each day. There always seems to be a surge of DHCP connection failures in the morning and then it carries on all day with at least 10% of the total clients being counted for.

Understand that this is likely dependent on the underlying network and how the VLAN's have been set-up in the past - though I am wondering if anyone has experienced something similar and if they had any ideas on the issue?

[y2 · Accepted solution]

Hi Ben,

The morning surge in the DHCP failures could be related to student devices associating with low signal quality as they enter the premises.  If there is a DHCP loadbalancer/backup server, the secondary server could be sending DHCP NAK.

It may be best to run some pcap over the air with control packets and wired at various points.

If you have the vSZ with latest ver hooked to Ruckus Analytics/AI, you may be able to retrieve some pcap files from the portal.

[BenConroy]

Hi There,

Thanks for your reply! You are definitely correct. I have been able to trace the AP connection failures to the closest buildings to our transport area. Low signal quality is definitely the cause

I will take your advice on the pcap files. Thanks again!