DHCP option 55 example

RouterOS General
1

hello
I would like to offer the option 55 to my clients, to ask these options: 1,3,6,43

can someone give me an example, please, of an option 55 set in MT ?

2

Option 55 is a dhcp client options (requested parameter list). If you want to request more than the standard options, you’ll have to supply the complete request list including 1 (subnet mask), 3 (gateway) and 6 (dns). Note that the MT probably will ignore option 43, but maybe you could do something with scripting (client bound script).

Client option 55 is a list of hexadecimal option codes. 43 is 2B in hex. To request option 43:


/ip dhcp-client option
add code=55 name=req_option_43 value=0x0103062b
/ip dhcp-client
set <num> dhcp-options=req_option_43,hostname,clientid

If you want to supply option 43 to your clients, use dhcp server options:


/ip dhcp-server option
add code=43 name=option_43 value="'whatever'"
/ip dhcp-server network
set <num> dhcp-option=option_43
3

Thank you.
I would like to give these options:
opt43, I have the url of the ACS.
Since the CPE doesnt not explicitily ask for opt 43… I am not able to send it the tr069 string for them.
I use an external dhcp server.
I would like to use the internal mikrotik dhcp.
I would like to test the opt 50.

So I need to paste your code and I will try

4

You want to pass-through option 43 from dhcp-client to dhcp-server? That’s gonna require some scripting.

E.g.


:if ($bound=1) do={
  :local acs ($"lease-options"->"43");
  :log info "DHCP Option 43: $acs";
  /ip dhcp-server option set option-43 value="'$acs'";
}

Or, in terminal format:


/ip dhcp-client option
add code=55 name=req_acs value=0x0103062b
/ip dhcp-server option
add code=43 name=option-43 value="''"
/ip dhcp-client
add dhcp-options=hostname,clientid,req_acs disabled=no interface=bridgeLocal script=\
    ":if (\$bound=1) do={\r\
    \n  :local acs (\$\"lease-options\"->\"43\");\r\
    \n  :log info \"DHCP Option 43: \$acs\";\r\
    \n  /ip dhcp-server option set option-43 value=\"'\$acs'\";\r\
    \n}"
5

Can you give me an email to contact directly?

6

Nope, not really.

Perhaps you’re trying to remote configure CPE’s, then you could take a look at https://wiki.mikrotik.com/wiki/Manual:TR069-client

7

Hello. I just wanted to share the conf with you without revealing the public url of acs server to double check the configuration. I am not sure I will succeed in this since the cpe doesnt formally ask for opt43. There are a lot ot threads in the forum… now I use a Win2019 dhcp server but I would like to have them on mt..

8

You cannot force the DHCP server of RouterOS to send options the client hasn’t asked for, as doing so would break the RFC. Mikrotik has refused to implement this although some ISPs asked for it because they cannot provide service to broken CPEs whose DHCP clients don’t ask for some options but need them to operate properly.

9

I was trying to find a workaround.
In ROS they confirmed me that they will implement the “force option” to the dhcpd