problem in trying to use dhcp options

LeoCombes · Wed Sep 05, 2012 4:48 pm

I need to give a autoconfiguration file to a modem via TFTP.
This works perfectly from the ISC-DHCP I use daily, but now I want have the option to do so in a RB1200.
In this way it works perfectly with ISC-DHCP:

# modem
host test_modem {
    hardware ethernet               00:50:c2:31:21:74;
    fixed-address                   172.31.1.5;
    option tftp-server-name         "172.31.1.1";
    option extensions-path-name     "autoconf.vlan010.acf";
}

To do this in Mikrotik, try to use option 66:

add code=66 name=option1 value=172.31.1.1

I add it in "networks":

add address=172.31.1.0/32 dhcp-option=option1 gateway=172.31.1.1 netmask=24

... but does not work. The Mikrotik gives the corresponding IP correctly, but does not return the TFTP parameter.

Then, after some more tests, I test with "dhcpdump" of Linux, that allows me to see what exactly the modem is requesting.

  TIME: 2012-09-04 19:57:08.002
    IP: 0.0.0.0 (0:50:c2:31:24:4f) > 255.255.255.255 (ff:ff:ff:ff:ff:ff)
    OP: 1 (BOOTPREQUEST)
 HTYPE: 1 (Ethernet)
  HLEN: 6
  HOPS: 0
   XID: 7ca9d708
  SECS: 0
 FLAGS: 7f80
CIADDR: 0.0.0.0
YIADDR: 0.0.0.0
SIADDR: 0.0.0.0
GIADDR: 0.0.0.0
CHADDR: 00:50:c2:31:24:4f:00:00:00:00:00:00:00:00:00:00
 SNAME: .
 FNAME: .
OPTION:  53 (  1) DHCP message type         1 (DHCPDISCOVER)
OPTION:  61 (  8) Client-identifier         01:00:50:c2:31:24:4f:00
OPTION:  51 (  4) IP address leasetime      -256 ()
OPTION:  51 (  4) IP address leasetime      -1 ()
OPTION:  55 ( 11) Parameter Request List      1 (Subnet mask)
					      3 (Routers)
					      6 (DNS server)
					     15 (Domainname)
					     18 (Extensions path)
					     66 (TFTP server name)
					    120 (SIP Servers DHCP Option)
					    135 (???)
					    213 (???)
					    214 (???)
					    215 (???)

Here you can see that instead of using the "option 66", the modem use "option 55" to require "TFTP server name" and other parameters.
Try in various ways but still does not work:

add code=55 name=option1 value="tftp-server-name=172.31.1.1"
add code=55 name=option1 value=0x363620342031373220333120312031
add code=55 name=option1 value="TFTP=172.31.1.1"

Anyone have any idea how to do this?

Aug · Wed Sep 05, 2012 6:34 pm

Take a look at previous post. Might help.
http://forum.mikrotik.com/viewtopic.php ... +option+66

problem in trying to use dhcp options

problem in trying to use dhcp options

Re: problem in trying to use dhcp options

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