DHCPD missing router option in DHCPACK

[Evan Hunt]

I've seen four reports of this exact bug in the past few weeks.  (And no
reports of it before that, which makes me think it was probably introduced
in 3.1.1--can you try 3.1.0 and see if it gets better?)

Affected devices so far are limited to HP printers and Blackboard credit
card readers; other sorts of devices on the same networks are fine.  So
far, everyone who's mentioned their OS was running Solaris, but that might
be a coincidence.  I have not been able to reproduce the problem locally.

One person was able to work around the problem by forcing the parameter
request list to a particular value in dhcpd.conf:

    class "hpprinter" {
        match substring(hardware,1,6);
        option dhcp-parameter-request-list 1, 3, 6, 12, 13, 15, 66, 67;
    }
    subclass "hpprinter" <ethernet address 1>;
    subclass "hpprinter" <ethernet address 2>;

Let me know what OS you're running and whether you can try 3.1.0.  Thanks.

On Thu, Jul 17, 2008 at 12:31:29PM +0100, Tom Griffin wrote:
> Hello,
> 
> We have observed behaviour which has changed between versions of dhcpd.
> 
> We were previously running V3.0rc1pl1 with no failover configured. We 
> have since tried both 3.1.1 and 4.0.0 with failover configured and found 
> it to generate incorrect DHCPACK packets which are missing the router 
> option for seemingly fine DHCPREQUESTs. This has so far only been 
> observed with some models of HP printers (Laserjet 2600/1022/6310, 
> Photosmart C5180, Officejet 7780).
> 
> A packet capture shows that the printers skip the DISCOVER/OFFER stage 
> and move straight to REQUEST, requesting a specific IP and various 
> options (in this order);
> 6 - Domain Name Server
> 3 - Router
> 1 - Subnet Mask
> 15 - Domain Name
> 66 - TFTP Server Name
> 67 - Bootfile Name
> 13 - Boot File Size
> 12 - Host Name
> 
> The dhcpd then responds with a DHCPACK containing the following options 
> (in this order);
> 53 - DHCP Message Type
> 54 - Server Identifier
> 51 - IP Address Lease Time
> 6 - Domain Name Server
> 1 - Subnet Mask
> 1 - Subnet Mask
> 15 - Domain Name
> 
> Other requested options are not returned since they are not configured 
> on the dhcp server (TFTP related options). Notice that the Subnet Mask 
> option is duplicated and the router option is missing. The router option 
> is definitely configured and working for the majority of devices on that 
> subnet.
> 
> Here is the configuration of one of the many affected subnets;
> 
>  subnet 143.167.16.0 netmask 255.255.252.0 {
>    option routers 143.167.16.254;
>    pool {
>      failover peer "coreserv";
>      range 143.167.17.184 143.167.17.220;
>      range 143.167.18.1 143.167.18.254;
>      range 143.167.19.100 143.167.19.190;
>      deny members of "subnetopen";
>      deny members of "subnetnone";
>      deny members of "ras-clients";
>      deny unknown clients;
>    }
>  }
> 
> And here an example configuration of a host experiencing the issue;
> 
>  host prt019239 { hardware ethernet 00:17:a4:31:87:34; fixed-address 
> 143.167.19.239; }
> 
> As a work-around we are using BOOTP with the affected devices as this 
> returns the correct information.
> 
> Regards,
> Tom Griffin
> Data Network Administrator
> The University of Sheffield
> 
> 

-- 
Evan Hunt -- evan_hunt at isc.org
Internet Systems Consortium, Inc.