Using DHCP option 43 to boot a Trapeze DAP from a Cisco DHCP scope

19 12 2006

A colleague of mine has recently been trying to get a Trapeze access-point to boot remotely from the MX switch by using DHCP option 43. This is what Trapeze refer to as a DAP – a Distributed Access Point.

Option 43 is what is known as the Vendor Specific Information DHCP Option. What should happen is that the AP boots up, does POST and does a DHCP request. The switch or router should send out a DHCP offer – an IP address to use, a default gateway to use and also the option 43 TLV. The TLV should contain the IP address of the MX switch where the AP needs to get its code and configuration from.

He’d configured a DHCP server pool on the Cisco switch where the DAP was attached. Within the scope he’d put the following:

option 43 IP A.B.C.D

which seems sensible, doesn’t it? Actually what was needed was:

option 43 ascii ip:A.B.C.D

If multiple MXes exist, their IP addresses can be strung together on the same line with a comma separating the IPs. Alternatively, hostnames cacn be used – just use the word host instead of the word ip.



2 responses

8 12 2009
Ari Pitkäranta

Shouldn´t there be quotation marks? Option 43 ascii “A.B.C.D” ?

18 04 2011

the “” will be added by the switch if you don’t put them in

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