DHCPD Client Classification

pxe tftpd dhcpd advanced client identifier http

pxelinux

VirtualBox shows

Option: (60) Vendor class identifier
    Length: 32
    Vendor class identifier: PXEClient:Arch:00000:UNDI:002001

Option: (77) User Class Information
    Length: 4
    User Class Data: 69505845

0000   4d 04 69 50 58 45                                 M.iPXE

netbsd

got its own vendor-class-identifier!

0000   4e 65 74 42 53 44 3a 69 33 38 36 3a 6c 69 62 73   NetBSD:i386:libs
0010   61                                                a

dfly

Dynamic Host Configuration Protocol (Discover)
    Message type: Boot Request (1)
    Hardware type: Ethernet (0x01)
    Hardware address length: 6
    Hops: 0
    Transaction ID: 0x0e82f7d5
    Seconds elapsed: 0
    Bootp flags: 0x0000 (Unicast)
    0... .... .... .... = Broadcast flag: Unicast
    .000 0000 0000 0000 = Reserved flags: 0x0000
    Client IP address: 0.0.0.0
    Your (client) IP address: 0.0.0.0
    Next server IP address: 0.0.0.0
    Relay agent IP address: 0.0.0.0
    Client MAC address: PcsCompu_a2:a6:e6 (08:00:27:a2:a6:e6)
    Client hardware address padding: 00000000000000000000
    Server host name not given
    Boot file name not given
    Magic cookie: DHCP
    Option: (53) DHCP Message Type (Discover)
    Length: 1
    DHCP: Discover (1)
    Option: (60) Vendor class identifier
    Length: 9
    Vendor class identifier: PXEClient
    Option: (255) End
    Option End: 255
    Padding: 000000000000000000000000000000000000000000000000…

got something specific on option (255)

0000   ff                                                .

fbsd

Dynamic Host Configuration Protocol (Discover)
    Message type: Boot Request (1)
    Hardware type: Ethernet (0x01)
    Hardware address length: 6
    Hops: 0
    Transaction ID: 0x4835f288
    Seconds elapsed: 0
    Bootp flags: 0x0000 (Unicast)
    0... .... .... .... = Broadcast flag: Unicast
    .000 0000 0000 0000 = Reserved flags: 0x0000
    Client IP address: 0.0.0.0
    Your (client) IP address: 0.0.0.0
    Next server IP address: 0.0.0.0
    Relay agent IP address: 0.0.0.0
    Client MAC address: PcsCompu_a2:a6:e6 (08:00:27:a2:a6:e6)
    Client hardware address padding: 00000000000000000000
    Server host name not given
    Boot file name not given
    Magic cookie: DHCP
    Option: (53) DHCP Message Type (Discover)
    Length: 1
    DHCP: Discover (1)
    Option: (60) Vendor class identifier
    Length: 9
    Vendor class identifier: PXEClient
    Option: (77) User Class Information
    Length: 8
    Instance of User Class: [0]
        User Class Length: 7
        User Class Data: 46726565425344
    Option: (55) Parameter Request List
    Length: 7
    Parameter Request List Item: (17) Root Path
    Parameter Request List Item: (12) Host Name
    Parameter Request List Item: (16) Swap Server
    Parameter Request List Item: (3) Router
    Parameter Request List Item: (1) Subnet Mask
    Parameter Request List Item: (26) Interface MTU
    Parameter Request List Item: (54) DHCP Server Identifier
    Option: (255) End
    Option End: 255
    Padding: 000000000000000000000000000000000000000000000000…

easy catch – user-class

0000   07 46 72 65 65 42 53 44                           .FreeBSD

Resources

dhcp-eval - ISC DHCP conditional evaluation https://www.freebsd.org/cgi/man.cgi?query=dhcp-eval

dhcp-options – Dynamic Host Configuration Protocol options https://www.freebsd.org/cgi/man.cgi?query=dhcp-options

Understanding Client Classification https://kb.isc.org/docs/understanding-client-classification

About Option Filters https://docs.infoblox.com/display/NAG8/About+Option+Filters

CLIENT CLASSING https://kb.isc.org/docs/isc-dhcp-41-manual-pages-dhcpdconf#CLIENT%20CLASSING

user-class

https://linux.die.net/man/5/dhcpd-options –> Vendor Encapsulated Options

DHCP user class setting https://ipxe.org/cfg/user-class

ISC DHCPD class is not assigned https://serverfault.com/questions/715011/isc-dhcpd-class-is-not-assigned

Sample configuration file for ISC dhcpd http://caia.swin.edu.au/tools/130226A/dhcpd-advanced.conf

examples

ISC DHCPD class is not assigned https://serverfault.com/questions/715011/isc-dhcpd-class-is-not-assigned

DHCP scope for a user class option https://serverfault.com/questions/509571/dhcp-scope-for-a-user-class-option

Selecting fixed or dynamic address based on vendor-class-identifier https://lists.isc.org/pipermail/dhcp-users/2013-October/017287.html

dhcpd.conf issue with class by vendor-class-identifier https://forums.contribs.org/index.php?topic=49641.0

Configuring a DHCP User Class ID https://help.netmotionsoftware.com/support/docs/MobilityXG/1100/help/mobilityhelp.htm#page/Mobility%20Server/design.02.39.html

DHCP Vendor Class Identifier – DHCP Option 60 https://www.flomain.de/2019/05/dhcp-vendor-class-identifier-dhcp-option-60/

mac / binary-to-ascii

https://unix.stackexchange.com/questions/417814/dhcpd-isnt-matching-this-mac-address

https://mwl.io/archives/962

https://linux.die.net/man/5/dhcpd-eval

https://kb.isc.org/docs/isc-dhcp-44-manual-pages-dhcp-eval

https://kb.isc.org/docs/aa-01039