Introduction- This configuration feature of DHCP option is available from Instant 3.3 and above.
- The scope of the this feature is to allow users to add the DHCP options to the IAP.
- The user configures the desired DHCP options for the DHCP profile with type and value.
- This feature is valid only for local DHCP servers not for centralized L2, where DHCP server runs on the controller.
- User can add DHCP option 242 for bringing up the Avaya phones with the data VLAN, voice VLAN and TFTP server IP address.
- Once this option is configured the Avaya phone will seek option 242 and the IAP will be able to serve this option with configured value.
Environment- Typical Environment of using any wired phones plugged into the network. In our example from network Topology you could see Avaya Phone is plugged into one of the switch port.
Configuration Steps- Configuration
From UI go to More > DHCP Servers
The below debug commands only display the headers of DHCP packets exchanged between IAP and the Client.
Answer- From the above configuration we could notice DHCP option 242 configuration is applied successfully.
Commands to verify
Troubleshooting- The below debug commands only display the headers of DHCP packets exchanged between IAP and the Client.
6c:f3:7f:c2:5d:fa# debug pkt type dhcp
6c:f3:7f:c2:5d:fa# debug pkt match type
6c:f3:7f:c2:5d:fa# debug pkt dump
Received packet from eth1 (timestamp 0219088168)
[asap_firewall_forward(3740):firewall entry] len 1038, vlan 0, egress CP, ingress eth1:
#mac: etype 0800 smac b4:b0:17:7f:75:c9 tmac ff:ff:ff:ff:ff:ff
#ip: sip 0.0.0.0, dip 255.255.255.255, proto 17, dont fragment, last fragment,
fragment offset 0
#udp: sport 68 dport 67 len 1004
#dhcp: message-type: request
hardware type: 1, len: 6
transaction id: be078b90
seconds elapsed: 0
boot flags: 0x0000
client ip: 0.0.0.0, your ip: 0.0.0.0
next server ip: 0.0.0.0, relay agent ip: 0.0.0.0
client mac: b4:b0:17:7f:75:c9
server host name: (null)
boot file name: (null)
magic cookie: 63825363
From the below screen shot you could notice the DHCP option 242 is configured.
Related Links- https://arubanetworkskb.secure.force.com/pkb/articles/HowTo/Debugging-DHCP-packets-on-Aruba-Instant-IAP