bootreply always-broadcast

[David W. Hankins]

curious.  i know bootp is handled differently (by different whole
sources) for dynamic-allocation and fixed-addresses, but i don't know
offhand what the bug is here.

open a ticket at dhcp-bugs at isc.org to remind us to fix it?

On Wed, Mar 19, 2008 at 11:05:18AM -0500, Kernel Jake wrote:
> 
> dhcpd V3.0.5 on FreeBSD 6.2 is not returning a broadcast BOOTREPLY to a 
> Cisco PowerConnect 3524 switch.
> The following is the BOOTREQUEST packet.  The client sets the broadcast flag.
> 
>   TIME: 08:33:12.432175
>     IP:> (00:1e:4f:09:af:71)>  (ff:ff:ff:ff:ff:ff)
>     OP: 1 (BOOTPREQUEST)
>  HTYPE: 1 (Ethernet)
>   HLEN: 6
>   HOPS: 0
>    XID: 52525230
>   SECS: 120
>  FLAGS: 7f80 (wireshark says 0x8000, dhcpdump says 0x7f80)
> CIADDR: 0.0.0.0
> YIADDR: 0.0.0.0
> SIADDR: 0.0.0.0
> GIADDR: 0.0.0.0
> CHADDR: 00:1e:4f:09:af:71:00:00:00:00:00:00:00:00:00:00
>  SNAME: .
>  FNAME: .
> OPTION:  12 ( 17) Host name                 PowerConnect 3524
> 
> If I use a pool of dynamic bootp addresses as specified in the following block,
> then the BOOTREPLY packet is sent the to the ethernet broadcast address 
> correctly, and the client accepts the reply.
> 
> subnet 192.168.2.0 netmask 255.255.255.0 {
>   range dynamic-bootp 192.168.2.160 192.168.2.170;
>   option routers 192.168.2.1;
> }
> 
>   TIME: 08:33:12.433487
>     IP:> (00:30:48:5e:6f:18)>  (ff:ff:ff:ff:ff:ff)
>     OP: 2 (BOOTPREPLY)             ^^^^^^^^^
>  HTYPE: 1 (Ethernet)
>   HLEN: 6
>   HOPS: 0
>    XID: 52525230
>   SECS: 120
>  FLAGS: 7f80
> CIADDR: 0.0.0.0
> YIADDR: 192.168.2.170
> SIADDR: 0.0.0.0
> GIADDR: 0.0.0.0
> CHADDR: 00:1e:4f:09:af:71:00:00:00:00:00:00:00:00:00:00
>  SNAME: .
>  FNAME: .
> OPTION:   1 (  4) Subnet mask               255.255.255.0
> OPTION:   3 (  4) Routers                   192.168.2.1
> 
> 
> However, if I use a group with fixed addresses, then the BOOTREPLY packet 
> is sent to the unicast address of the client, and the client ignores the reply.
> 
> subnet 192.168.2.0 netmask 255.255.255.0 { }
> group dell {
>   option routers 192.168.2.1;
>   host dell01 { hardware ethernet 00:1E:4F:09:AF:71; 
>           fixed-address 192.168.2.160; always-broadcast on; }
> }
> 
> 
>   TIME: 08:32:22.633798
>     IP:> (00:30:48:5e:6f:18)>  (00:1e:4f:09:af:71)
>     OP: 2 (BOOTPREPLY)              ^^^^^^^^^^^
>  HTYPE: 1 (Ethernet)
>   HLEN: 6
>   HOPS: 0
>    XID: 52525230
>   SECS: 70
>  FLAGS: 7f80
> CIADDR: 0.0.0.0
> YIADDR: 192.168.2.160
> SIADDR: 192.168.2.1
> GIADDR: 0.0.0.0
> CHADDR: 00:1e:4f:09:af:71:00:00:00:00:00:00:00:00:00:00
>  SNAME: .
>  FNAME: .
> OPTION:   1 (  4) Subnet mask               255.255.255.0
> OPTION:   3 (  4) Routers                   192.168.2.1
> 
> The dhcpd.conf manpage says that the relevant scope for always-broadcast
> is a conditional statement, parameter for a class, or as a parameter for a 
> host declaration.  What is going wrong?
> 
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-- 
David W. Hankins	"If you don't do it right the first time,
Software Engineer		you'll just have to do it again."
Internet Systems Consortium, Inc.	-- Jack T. Hankins