[Dnsmasq-discuss] dnsmasq ignoring some clients
Chris Marget
chris at logsoft.com
Thu Oct 2 18:14:10 BST 2008
On Thu, 2 Oct 2008, Simon Kelley wrote:
> Chris Marget wrote:
>
> > Option: (t=50,l=4) Requested IP Address = 255.255.255.255
> > Option: (50) Requested IP Address
> > Length: 4
> > Value: FFFFFFFF
> ^^^^^^^^
> The client is asking for IP address 255.255.255.255, that doesn't look
> right at all. A server identifier of 1.2.3.4 looks suspicious too, is
> that the IP address of you DHCP server?
Hi Simon. Thank you for your attention.
Here's the scoop. the client is a disk image of a pre-installed linux
system. I got it here: http://jailtime.org/download:centos:v5.2
It's a pre-built "drop into your xvm engine" kind of thing, and comes
with the baggage of the environment of the guy who built it.
So, yes, the client is very confused about his environment.
I agree that asking for 255.255.255.255 is somewhat strange, but
shouldn't dnsmasq NAK this request just like any other transplanted
client?
My other DHCP server (ISC - running on a different box) serves this
client just fine. The authoritative statement is required, of course.
Here's the transaction according to the ISC server's debug output:
DHCPREQUEST for 255.255.255.255 (1.2.3.4) from 00:16:3e:11:11:11 via nge0: wrong network.
DHCPNAK on 255.255.255.255 to 00:16:3e:11:11:11 via nge0
DHCPDISCOVER from 00:16:3e:11:11:11 via nge0
DHCPOFFER on 192.168.1.81 to 00:16:3e:11:11:11 via nge0
DHCPREQUEST for 192.168.1.81 (192.168.1.8) from 00:16:3e:11:11:11 via nge0
DHCPACK on 192.168.1.81 to 00:16:3e:11:11:11 via nge0
...and now the (rather lengthy) dump of the 6 packets associated with
the 6 lines of debug output. I've trimmed the lower layer protocol
details in an attempt at brevity.
Thanks!
/chris
DHCPREQUEST for 255.255.255.255 (1.2.3.4) from 00:16:3e:11:11:11 via
nge0: wrong network.
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0xdcbfd683
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 (0.0.0.0)
Your (client) IP address: 255.255.255.255 (255.255.255.255)
Next server IP address: 255.255.255.255 (255.255.255.255)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Xensourc_11:11:11 (00:16:3e:11:11:11)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option: (t=53,l=1) DHCP Message Type = DHCP Request
Option: (53) DHCP Message Type
Length: 1
Value: 03
Option: (t=54,l=4) Server Identifier = 1.2.3.4
Option: (54) Server Identifier
Length: 4
Value: 01020304
Option: (t=50,l=4) Requested IP Address = 255.255.255.255
Option: (50) Requested IP Address
Length: 4
Value: FFFFFFFF
Option: (t=55,l=7) Parameter Request List
Option: (55) Parameter Request List
Length: 7
Value: 0103060C0F1128
1 = Subnet Mask
3 = Router
6 = Domain Name Server
12 = Host Name
15 = Domain Name
17 = Root Path
40 = Network Information Service Domain
End Option
Padding
DHCPNAK on 255.255.255.255 to 00:16:3e:11:11:11 via nge0
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0xdcbfd683
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
1... .... .... .... = Broadcast flag: Broadcast
.000 0000 0000 0000 = Reserved flags: 0x0000
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 192.168.1.8 (192.168.1.8)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Xensourc_11:11:11 (00:16:3e:11:11:11)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option: (t=53,l=1) DHCP Message Type = DHCP NAK
Option: (53) DHCP Message Type
Length: 1
Value: 06
Option: (t=54,l=4) Server Identifier = 192.168.1.8
Option: (54) Server Identifier
Length: 4
Value: C0A80108
End Option
Padding
DHCPDISCOVER from 00:16:3e:11:11:11 via nge0
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0xdcbfd683
Seconds elapsed: 2
Bootp flags: 0x0000 (Unicast)
0... .... .... .... = Broadcast flag: Unicast
.000 0000 0000 0000 = Reserved flags: 0x0000
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 255.255.255.255 (255.255.255.255)
Next server IP address: 255.255.255.255 (255.255.255.255)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Xensourc_11:11:11 (00:16:3e:11:11:11)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option: (t=53,l=1) DHCP Message Type = DHCP Discover
Option: (53) DHCP Message Type
Length: 1
Value: 01
Option: (t=55,l=7) Parameter Request List
Option: (55) Parameter Request List
Length: 7
Value: 0103060C0F1128
1 = Subnet Mask
3 = Router
6 = Domain Name Server
12 = Host Name
15 = Domain Name
17 = Root Path
40 = Network Information Service Domain
End Option
Padding
DHCPOFFER on 192.168.1.81 to 00:16:3e:11:11:11 via nge0
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0xdcbfd683
Seconds elapsed: 2
Bootp flags: 0x0000 (Unicast)
0... .... .... .... = Broadcast flag: Unicast
.000 0000 0000 0000 = Reserved flags: 0x0000
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 192.168.1.81 (192.168.1.81)
Next server IP address: 192.168.1.1 (192.168.1.1)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Xensourc_11:11:11 (00:16:3e:11:11:11)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option: (t=53,l=1) DHCP Message Type = DHCP Offer
Option: (53) DHCP Message Type
Length: 1
Value: 02
Option: (t=54,l=4) Server Identifier = 192.168.1.1
Option: (54) Server Identifier
Length: 4
Value: C0A80101
Option: (t=51,l=4) IP Address Lease Time = 16 hours, 14 minutes, 56
seconds
Option: (51) IP Address Lease Time
Length: 4
Value: 0000E480
Option: (t=58,l=4) Renewal Time Value = 8 hours, 7 minutes, 28
seconds
Option: (58) Renewal Time Value
Length: 4
Value: 00007240
Option: (t=59,l=4) Rebinding Time Value = 14 hours, 13 minutes, 4
seconds
Option: (59) Rebinding Time Value
Length: 4
Value: 0000C7F0
Option: (t=1,l=4) Subnet Mask = 255.255.255.0
Option: (1) Subnet Mask
Length: 4
Value: FFFFFF00
Option: (t=15,l=3) Domain Name = "lan"
Option: (15) Domain Name
Length: 3
Value: 6C616E
Option: (t=6,l=4) Domain Name Server = 192.168.1.1
Option: (6) Domain Name Server
Length: 4
Value: C0A80101
Option: (t=3,l=4) Router = 192.168.1.1
Option: (3) Router
Length: 4
Value: C0A80101
End Option
Padding
DHCPREQUEST for 192.168.1.81 (192.168.1.8) from 00:16:3e:11:11:11 via
nge0
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0xdcbfd683
Seconds elapsed: 2
Bootp flags: 0x0000 (Unicast)
0... .... .... .... = Broadcast flag: Unicast
.000 0000 0000 0000 = Reserved flags: 0x0000
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 255.255.255.255 (255.255.255.255)
Next server IP address: 255.255.255.255 (255.255.255.255)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Xensourc_11:11:11 (00:16:3e:11:11:11)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option: (t=53,l=1) DHCP Message Type = DHCP Request
Option: (53) DHCP Message Type
Length: 1
Value: 03
Option: (t=54,l=4) Server Identifier = 192.168.1.8
Option: (54) Server Identifier
Length: 4
Value: C0A80108
Option: (t=50,l=4) Requested IP Address = 192.168.1.81
Option: (50) Requested IP Address
Length: 4
Value: C0A80151
Option: (t=55,l=7) Parameter Request List
Option: (55) Parameter Request List
Length: 7
Value: 0103060C0F1128
1 = Subnet Mask
3 = Router
6 = Domain Name Server
12 = Host Name
15 = Domain Name
17 = Root Path
40 = Network Information Service Domain
End Option
Padding
DHCPACK on 192.168.1.81 to 00:16:3e:11:11:11 via nge0
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0xdcbfd683
Seconds elapsed: 2
Bootp flags: 0x0000 (Unicast)
0... .... .... .... = Broadcast flag: Unicast
.000 0000 0000 0000 = Reserved flags: 0x0000
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 192.168.1.81 (192.168.1.81)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Xensourc_11:11:11 (00:16:3e:11:11:11)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option: (t=53,l=1) DHCP Message Type = DHCP ACK
Option: (53) DHCP Message Type
Length: 1
Value: 05
Option: (t=54,l=4) Server Identifier = 192.168.1.8
Option: (54) Server Identifier
Length: 4
Value: C0A80108
Option: (t=51,l=4) IP Address Lease Time = 12 hours
Option: (51) IP Address Lease Time
Length: 4
Value: 0000A8C0
Option: (t=1,l=4) Subnet Mask = 255.255.255.0
Option: (1) Subnet Mask
Length: 4
Value: FFFFFF00
Option: (t=3,l=4) Router = 192.168.1.1
Option: (3) Router
Length: 4
Value: C0A80101
Option: (t=6,l=8) Domain Name Server
Option: (6) Domain Name Server
Length: 8
Value: C0A8010104020201
IP Address: 192.168.1.1
IP Address: 4.2.2.1
End Option
Padding
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