When specifying dhcp-option 67 (bootfile-name), the bootfile-name packet header in the DHCP offer sent from the mikrotik is not populated:
ip dhcp-server lease print detail
;;; Example Lease
address=10.0.100.2 mac-address=xx:xx:xx:xx:xx:xx lease-time=5m dhcp-option="bootfile"
ip dhcp-server option print detail
;;;Example Option
name="bootfile" code=67 value="'filename.ext'" raw-value="66696c656e616d652e657874"
Results in the following when client does not specifically request option 67, bootfile-name is not populated and option 67 is not present:
Bootstrap Protocol (Offer)
Message type: Boot Reply (2)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x7e1ed939
Seconds elapsed: 0
Bootp flags: 0x0000 (Unicast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 10.0.100.2 (10.0.100.2)
Next server IP address: 10.0.100.1 (10.0.100.1)
Relay agent IP address: 10.0.100.1 (10.0.100.1)
Client MAC address: xxxx (xx:xx:xx:xx:xx:xx)
Client hardware address padding: 00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type (Offer)
Option: (54) DHCP Server Identifier
Option: (51) IP Address Lease Time
Option: (1) Subnet Mask
Option: (3) Router
Option: (6) Domain Name Server
Option: (255) End
If the client specifically requests option 67, mikrotik will return the following, again bootfile-name is not populated but option 67 is present-
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type (Offer)
Option: (54) DHCP Server Identifier
Option: (51) IP Address Lease Time
Option: (1) Subnet Mask
Option: (3) Router
Option: (6) Domain Name Server
Option: (67) Bootfile Name
Length: 12
Bootfile Name: filename.ext
Option: (255) End
Per testing with other DHCP servers (windows/cisco) when specifying option 67, the bootfile-name packet header is always populated and the Option: (67) packet header is not present. This stands true both when client requests and does not request option 67.
When I refer to the client requesting option 67, I am referring to "Option (55): Parameter Request List" sent in the DHCP discover.
Not sure if I have a miss-configuration or this is a potential bug, any thoughts or insight?
Thanks,
-dan