SV: Brother printer and option "routers"

Anders Rosendal anders at
Sat Dec 13 10:29:59 UTC 2008

Have you tried removing all options that are not 100% necessary to get IP-connectivity?

I have seen quite a few examples when the dhcp-client fail just because you try to feed it with more information than it can handle.

I would try removing all options other then the router-option. If you have both pc-clients and printers on the same subnet you need to create a class matching just the printers, and in there class only put the routing option. Observe also that options declared in the global context are inherited to classes. This means that you must create a class for everything not matching the printers and move your options such as dns there.

Just for testing purposes you might comment out all for the printers "unnecessary" options for a couple of minutes in your "off-hours" and make a printer lease a address under those circumstances.

Regards Anders Rosendal

-----Ursprungligt meddelande-----
Från: dhcp-users-bounces at [mailto:dhcp-users-bounces at] För Tina Siegenthaler
Skickat: den 12 december 2008 16:22
Till: Users of ISC DHCP
Ämne: Re: Brother printer and option "routers"

> Check the packets on the wire with a packet sniffer (eg wireshark) -  
> specifically you are looking for the list of options requested, and  
> the list of options supplied. IIRC there is a bug in one or more  
> recent versions where the client can ask for a list of options, and  
> the server sorts them (to put routers, subnet mask, etc) at the  
> beginning. The bug manifests itself if the client asks for options  
> in a particular order, and the server sends one option twice and  
> omits another.
> -- 
> Simon Hobson

Hi Simon

This is what I'm seeing on the DHCP server:

Parameter request list from the printer on DISCOVER:

     Option: (t=55,l=9) Parameter Request List
         Option: (55) Parameter Request List
         Length: 9
         Value: 0603010F42430D0C2C
         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
         44 = NetBIOS over TCP/IP Name Server

Options sent by the DHCP server on OFFER:

     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 =
         Option: (54) Server Identifier
         Length: 4
         Value: 823C9104
     Option: (t=51,l=4) IP Address Lease Time = 6 hours
         Option: (51) IP Address Lease Time
         Length: 4
         Value: 00005460
     Option: (t=1,l=4) Subnet Mask =
         Option: (1) Subnet Mask
         Length: 4
         Value: FFFFFF80
     Option: (t=3,l=4) Router =
         Option: (3) Router
         Length: 4
         Value: 823CE101
     Option: (t=6,l=8) Domain Name Server
         Option: (6) Domain Name Server
         Length: 8
         Value: 823C8003823C4033
         IP Address:
         IP Address:
     Option: (t=58,l=4) Renewal Time Value = 3 hours
         Option: (58) Renewal Time Value
         Length: 4
         Value: 00002A30
     Option: (t=59,l=4) Rebinding Time Value = 5 hours, 15 minutes
         Option: (59) Rebinding Time Value
         Length: 4
         Value: 000049D4
     Option: (t=28,l=4) Broadcast Address =
         Option: (28) Broadcast Address
         Length: 4
         Value: 823CE17F
     Option: (t=15,l=8) Domain Name = ""
         Option: (15) Domain Name
         Length: 8
         Value: 756E697A682E6368

The server sends the options in a different order than the printer  
asked for, but the router address is sent and sent correctly, and  
there are no duplicate options. So it really seems to be the printers  
which for some reason or another don't accept the routers option.


dhcp-users mailing list
dhcp-users at

This message has been scanned for viruses and
dangerous content by MailScanner on,
and is believed to be clean.

This message has been scanned for viruses and
dangerous content by MailScanner on,
and is believed to be clean.

More information about the dhcp-users mailing list