Help troubleshooting: Advertised lease scored 0, toss it.

[John W. Blue]

Bruce,

Thanks for the response.

I am working from a position of not using a configuration profile initially.  It would make sense that if dhclient was expecting a conf file that it would complain about it.  But, I would expect it to say "Where's the conf file?" instead of that the advertised lease scored a zero.

As you can see here, the router when it responds with its "advertise" packet that it includes the DNS servers and the IA Address:

Frame 113: 182 bytes on wire (1456 bits), 182 bytes captured (1456 bits)
Ethernet II, Src: Cisco_6d:28:d9 (e0:2f:6d:6d:28:d9), Dst: Vmware_ba:a7:4c (00:0c:29:ba:a7:4c)
Internet Protocol Version 6, Src: fe80::e22f:6dff:fe6d:28d9, Dst: fe80::20c:29ff:feba:a74c
User Datagram Protocol, Src Port: 547, Dst Port: 546
DHCPv6
    Message type: Advertise (2)
    Transaction ID: 0x89405a
    Client Identifier
        Option: Client Identifier (1)
        Length: 14
        Value: 0001000123bd8128000c29baa74c
        DUID: 0001000123bd8128000c29baa74c
        DUID Type: link-layer address plus time (1)
        Hardware type: Ethernet (1)
        DUID Time: Dec 31, 2018 19:38:48.000000000 Central Standard Time
        Link-layer address: 00:0c:29:ba:a7:4c
    Server Identifier
        Option: Server Identifier (2)
        Length: 14
        Value: 0001000155d45514f8bc123d6ca8
        DUID: 0001000155d45514f8bc123d6ca8
        DUID Type: link-layer address plus time (1)
        Hardware type: Ethernet (1)
        DUID Time: Aug 18, 2045 05:06:12.000000000 Central Daylight Time
        Link-layer address: f8:bc:12:3d:6c:a8
    DNS recursive name server
        Option: DNS recursive name server (23)
        Length: 32
        Value: 20010578003f0000000000000000001020010578003f0001...
         1 DNS server address: 2001:578:3f::10
         2 DNS server address: 2001:578:3f:1::10
    Identity Association for Non-temporary Address
        Option: Identity Association for Non-temporary Address (3)
        Length: 40
        Value: 29baa74c0000a8c000010e000005001820010579ff010100...
        IAID: 29baa74c
        T1: 43200
        T2: 69120
        IA Address
            Option: IA Address (5)
            Length: 24
            Value: 20010579ff010100f9b0a8ffed83c0d80001518000015180
            IPv6 address: 2001:579:ff01:100:f9b0:a8ff:ed83:c0d8
            Preferred lifetime: 86400
            Valid lifetime: 86400


If it is a you are indicating that dhclient is expecting a conf file is there a way to disable that behavior so it does not have to talk to null?

John

-----Original Message-----
From: Bruce Hudson [mailto:Bruce.Hudson at dal.ca] 
Sent: Friday, January 11, 2019 1:58 PM
To: John W. Blue
Subject: Re: Help troubleshooting: Advertised lease scored 0, toss it.

On Fri, Jan 11, 2019 at 06:49:32PM +0000, John W. Blue wrote:

> So the solution is to include "-cf /dev/null" on the command line:
> "/usr/local/sbin/dhclient -v -6 -cf /dev/null em0"
> 
> I do not understand why this makes it work whereas without it it fails.
> Thoughts?

    Well, your "fix" is to prevent dhclient from reading the default configuration file by telling it to read "/dev/null" instead. The obvious implication is that something in the existing file that is breaking things. The most likely, off the top of my head, is that your configuration is set to require an option that is not being provided. That instantly triggers a score of zero. 

    For example, the example configuration file that comes with the software requires "subnet-mask" and "domain-name-servers"; neither of which are in the lease you are getting.

    I am sorry if you have previously provided the configuration file. I confess I have not really been following the thread. 
-- 
Bruce A. Hudson				| Bruce.Hudson at Dal.CA
ITS, Networks and Systems		|
Dalhousie University			|
Halifax, Nova Scotia, Canada		| (902) 494-3405