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DHCP server not working for iPXE

DHCP server not working for iPXE

New Contributor

The switch is BlackDiamond X8.
I’ve set dhcp server for our lab VLAN that I’m using for testing. The pool range and everything else works as intended.
I’ve configured options 66 and 67 to FOG server machine and that’s where it breaks. I’m getting:

Filename: undionly.kpxe
Could not start download: Operation not supported (


I can confirm that when using separate isc-dhcp server there’s no problem. But I’d like to utilize our switch.

Here’s snippet of my configuration:

    DHCP Address Range   : 192.168.xx.xx->192.168.xx.xx
    Netlogin Lease Timer : Not configured (Default = 10 seconds)
    DHCP Lease Timer     : 86400 seconds
    Default Gateway      : 192.168.xx.xx
    Primary DNS Server   : xx.xx.xx.xx
    DHCP Option Code  66 : ipaddress 192.168.xx.xx
    DHCP Option Code  67 : string "undionly.kpxe"
    Ports DHCP Enabled   : 1:21


New Contributor

Ah, it is what it is I guess 🙂
Anyway, thank you for your time and for bearing with me.

Valued Contributor III

Based on the traces and the information from you it is probably so that your client cannot evaluate the option 66. After you have converted the option 66 into a string it is transmitted correctly your client does not process the information however.

The clients I have seen so far can do both option 66/67 and "next-server", your client seems to be different. 
Your client waits for the DHCP info "Next-Server" where "Next-Server" != Option 66. "Next-Server" is not a classic DHCP option so it has no option number. As far as I know XOS supports only options with a number.

Therefore you can't solve the issue with XOS. Which client do you use?

I assume if you configure option 60/67 on the ICS your client won’t work.



Regards Stephan

New Contributor

I forgot to mention - the ACK and the offer messages are same. No 66/67 options in them.

This is the Request:


Frame 276: 463 bytes on wire (3704 bits), 463 bytes captured (3704 bits) on interface \Device\NPF_{4C63F991-A548-48B3-A772-5278B943AE7F}, id 0
Ethernet II, Src: 82:5d:c6:8a:7e:48 (82:5d:c6:8a:7e:48), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol Version 4, Src:, Dst:
User Datagram Protocol, Src Port: 68, Dst Port: 67
Dynamic Host Configuration Protocol (Request)
Message type: Boot Request (1)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x606b2926
Seconds elapsed: 18
Bootp flags: 0x8000, Broadcast flag (Broadcast)
Client IP address:
Your (client) IP address:
Next server IP address:
Relay agent IP address:
Client MAC address: 82:5d:c6:8a:7e:48 (82:5d:c6:8a:7e:48)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type (Request)
Option: (57) Maximum DHCP Message Size
Option: (93) Client System Architecture
Option: (94) Client Network Device Interface
Option: (60) Vendor class identifier
Option: (77) User Class Information
Option: (55) Parameter Request List
Option: (175) Etherboot
Option: (61) Client identifier
Option: (97) UUID/GUID-based Client Identifier
Option: (54) DHCP Server Identifier (
Option: (50) Requested IP Address (
Option: (255) End


Valued Contributor III

Hello asked you to check the other messages, because the messages you posted is the ack:



The ACK is from the client and it’s importent do check the other files.  Maybe there was the option 66/67 set.

Regards Stephan