[Kea-users] Invalid DHCP Server Identifier: 0.0.0.0

[Marcin Siodelski]

On 30.08.2016 17:42, Adam Twardowski wrote:
> I am running kea on FreeBSD.  I have a cisco router configured as a dhcp
> relay, forwarding requests to Kea.  Kea receives the requests and sends
> out a reply, but the reply has option 54 set to 0.0.0.0, which as far as
> I know doesn't make any sense.  The DHCP client can't continue the
> transaction because it obviously can't send a packet to 0.0.0.0.  Is
> there any way I can tell kea to send a valid server identifier?
> 
> 
> Config:
> 
> {
> "Dhcp4":
> {
>   "interfaces-config": {
>     "interfaces": [ "em0" ],
>     "dhcp-socket-type": "udp"
>   },
>   "lease-database": {
>     "type": "memfile",
>     "lfc-interval": 1800
>   },
>   "expired-leases-processing": {
>     "reclaim-timer-wait-time": 10,
>     "flush-reclaimed-timer-wait-time": 25,
>     "hold-reclaimed-time": 3600,
>     "max-reclaim-leases": 100,
>     "max-reclaim-time": 250,
>     "unwarned-reclaim-cycles": 5
>   },
> 
>   "valid-lifetime": 4000,
> 
>   "subnet4": [
>   {    "subnet": "10.128.224.0/20",
>        "pools": [ { "pool": "10.128.239.3 - 10.128.239.254" } ],
>        "option-data": [
>             { "name": "routers", "data": "10.128.224.1" },
>             { "name": "domain-name-servers", "data": "8.8.8.8, 8.8.4.4" },
>         ]
>   }
>   ]
> },
> 
> 
> 
> Kea Reply:
> 
> Bootstrap Protocol (Offer)
>     Message type: Boot Reply (2)
>     Hardware type: Ethernet (0x01)
>     Hardware address length: 6
>     Hops: 1
>     Transaction ID: 0xccc20000
>     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: 10.128.239.4
>     Next server IP address: 0.0.0.0
>     Relay agent IP address: 10.128.224.1
>     Client MAC address: ---------- DELETED -----------
>     Client hardware address padding: 00000000000000000000
>     Server host name not given
>     Boot file name not given
>     Magic cookie: DHCP
>     Option: (1) Subnet Mask
>         Length: 4
>         Subnet Mask: 255.255.240.0
>     Option: (3) Router
>         Length: 4
>         Router: 10.128.224.1
>     Option: (6) Domain Name Server
>         Length: 8
>         Domain Name Server: 8.8.8.8
>         Domain Name Server: 8.8.4.4
>     Option: (51) IP Address Lease Time
>         Length: 4
>         IP Address Lease Time: (4000s) 1 hour, 6 minutes, 40 seconds
>     Option: (53) DHCP Message Type (Offer)
>         Length: 1
>         DHCP: Offer (2)
>     Option: (54) DHCP Server Identifier
>         Length: 4
>         DHCP Server Identifier: 0.0.0.0
>     Option: (255) End
>         Option End: 255
> 

Adam,

Would it be possible for you to send us the dump of the DHCPDISCOVER
which triggers this response, along with the entire Ethernet/IP/UDP stack?

Thanks,
Marcin Siodelski
ISC