CR-2026-03-10: C9130AX WiFi 6 Access Point Deployment

Change Summary

Change ID

CR-2026-03-10-001

Date

2026-03-10

Priority

Medium

Type

Configuration Change

Systems

bind-01, bind-02, ISE, C3560-CX, WLC HA cluster

Status

Completed

Problem Statement

Replacement Cisco C9130AX access point required WLC discovery to join the wireless infrastructure. Standard approach (DHCP Option 43) was unavailable.

Challenge: VyOS (our DHCP server) only supports Ubiquiti vendor options natively - no Cisco Option 43 support.

Technical Background

Cisco AP WLC discovery methods (in priority order):

Method Description Available?

Method	Description	Available?
DHCP Option 43	Vendor-specific TLV with WLC IPs	Not supported by VyOS
DHCP Option 138	CAPWAP standard	AP requests Option 43, not 138
DNS-based discovery	`CISCO-CAPWAP-CONTROLLER.<domain>` A records	Used this
Broadcast discovery	Local subnet only	Not viable (WLCs on different VLAN)
Static configuration	Manual per-AP	Not scalable

DHCP Option 43

Vendor-specific TLV with WLC IPs

Not supported by VyOS

DHCP Option 138

CAPWAP standard

AP requests Option 43, not 138

DNS-based discovery

CISCO-CAPWAP-CONTROLLER.<domain> A records

Used this

Broadcast discovery

Local subnet only

Not viable (WLCs on different VLAN)

Static configuration

Manual per-AP

Not scalable

Solution

Add DNS A records for CISCO-CAPWAP-CONTROLLER pointing to both WLCs in the HA cluster.