dhclient doesn't send DHCP options

[Joshua Schaeffer <jschaeffer0922@gmail.com>]

Anybody seen this issue where dhclient does not send the user-class option in it's solicit message. I have a minimal dhclient.conf file and when I start dhclient I can see that option 15 isn't sent:

    root@blldhcptest01:~# cat /etc/dhcp/dhclient.conf
    send            user-class    "dhcp server";
    request            time-offset, host-name, dhcp6.name-servers, dhcp6.domain-search, dhcp6.fqdn;
    do-forward-updates    off;

    root@blldhcptest01:~# dhclient -6 -pf /run/dhclient6.eth0.pid -I eth0 -d -v -cf /etc/dhcp/dhclient.conf
    Internet Systems Consortium DHCP Client 4.3.3
    Copyright 2004-2015 Internet Systems Consortium.
    All rights reserved.
    For info, please visit https://www.isc.org/software/dhcp/

    Listening on Socket/eth0
    Sending on   Socket/eth0
    PRC: Soliciting for leases (INIT).
    XMT: Forming Solicit, 0 ms elapsed.
    XMT:  X-- IA_NA 3e:1e:cd:ff
    XMT:  | X-- Request renew in  +3600
    XMT:  | X-- Request rebind in +5400
    XMT: Solicit on eth0, interval 1030ms.
    RCV: Advertise message on eth0 from fe80::216:3eff:fe11:10ab.
    RCV:  X-- IA_NA 3e:1e:cd:ff
    RCV:  | X-- starts 1500753449
    RCV:  | X-- t1 - renew  +0
    RCV:  | X-- t2 - rebind +0
    RCV:  | X-- [Options]
    RCV:  X-- Server ID: 00:01:00:01:21:04:51:d0:00:16:3e:11:10:ab
    IA_NA status code NoAddrsAvail: "No addresses available for this interface."

And I don't see the option in the packet:

    No.     Time        Source                Destination           Protocol Length Info
          2 1.640863    fe80::216:3eff:fe1e:cdff ff02::1:2             DHCPv6   116    Solicit XID: 0x7ea155 CID: 00010001210664ed00163e1ecdff

    Frame 2: 116 bytes on wire (928 bits), 116 bytes captured (928 bits)
    Ethernet II, Src: Xensourc_1e:cd:ff (00:16:3e:1e:cd:ff), Dst: IPv6mcast_01:00:02 (33:33:00:01:00:02)
    Internet Protocol Version 6, Src: fe80::216:3eff:fe1e:cdff (fe80::216:3eff:fe1e:cdff), Dst: ff02::1:2 (ff02::1:2)
    User Datagram Protocol, Src Port: 546 (546), Dst Port: 547 (547)
    DHCPv6
        Message type: Solicit (1)
        Transaction ID: 0x7ea155
        Client Identifier
            Option: Client Identifier (1)
            Length: 14
            Value: 00010001210664ed00163e1ecdff
            DUID: 00010001210664ed00163e1ecdff
            DUID Type: link-layer address plus time (1)
            Hardware type: Ethernet (1)
            DUID Time: Jul 22, 2017 13:33:01.000000000 MDT
            Link-layer address: 00:16:3e:1e:cd:ff
        Option Request
            Option: Option Request (6)
            Length: 6
            Value: 001700180027
            Requested Option code: DNS recursive name server (23)
            Requested Option code: Domain Search List (24)
            Requested Option code: Fully Qualified Domain Name (39)
        Elapsed time
            Option: Elapsed time (8)
            Length: 2
            Value: 0000
            Elapsed time: 0 ms
        Identity Association for Non-temporary Address
            Option: Identity Association for Non-temporary Address (3)
            Length: 12
            Value: 3e1ecdff00000e1000001518
            IAID: 3e1ecdff
            T1: 3600
            T2: 5400

I have classes defined on my DHCP server that requires the user-class option and because it isn't being sent it can't match the client to any class and as such returns a NoAddrsAvail status code is returned. Anybody encountered this before and know how to fix it?

Thanks,
Joshua Schaeffer