DHCP option code 224-254 (privat use)

RouterOS General
1

Hi!

I migrated my firewall from linux (Debian) to Mikrotik, but i found a problem.
I can’t use mikrotik dhcp server option code 252. This is for automatic proxy
setting.

In ISC dhcp server :

option local-pac-server code 252 = text;
option local-pac-server "http://192.168.19.254/proxy.pac";

in mikrotik:

/ip dhcp-server option add name="local-pac-server" code=252 value="http://192.168.19.254/proxy.pac"

and I added it to networks.

As I see, it doesnt send the option code to the client.
Is it possible, that Mikrotik software can’t manage option codes after 224 ?

I’m tried with different versions of MT, and tried with the latest too…

Do u have any idea?

Thx,
chichken

2

option 249 works for me on v3.7 - so no 224 limit =)

3

Yes, u are right. I’m tried it, and worked, but 252 didn’t works…

4

Where can you find a list of what options do what?

5

In the forum :slight_smile:
http://forum.mikrotik.com/t/dhcp-options-example/16609/29

the 3rd answer: http://www.iana.org/assignments/bootp-dhcp-parameters

For my original post: Any Mikrotik developer here ? :slight_smile:

6

Hi again,

i’m tried to find out what is the difference in isc dhcp server and mikrotik dhcp server.

I used tcpdump and i found internesting thing :slight_smile:

First isc server dump (only the ack packet):

Option: (t=53,l=1) DHCP Message Type = DHCP ACK
Option: (t=54,l=4) Server Identifier = 192.192.192.113
Option: (t=1,l=4) Subnet Mask = 255.255.255.0
Option: (t=3,l=4) Router = 192.192.192.111
Option: (t=6,l=4) Domain Name Server = 192.192.192.2
Option: (t=44,l=4) NetBIOS over TCP/IP Name Server = 192.192.192.2
Option: (t=252,l=32) Proxy autodiscovery = "http://192.192.192.113/proxy.pac"

Don’t tell me too much about 192.192.192.x network… my client wanna it. Forget it.

You can see the last Option, the isc dhcp server sent the 252-es option code.

Second the mikrotik dhcp dump:

Option: (t=53,l=1) DHCP Message Type = DHCP ACK
Option: (t=54,l=4) Server Identifier = 192.168.95.147
Option: (t=51,l=4) IP Address Lease Time = 3 days
Option: (t=1,l=4) Subnet Mask = 255.255.255.0
Option: (t=15,l=8) Domain Name = "abcd.xy"
Option: (t=3,l=4) Router = 192.192.192.111

Hmm hmm, i can’t see the required option code… Why?
Maybe it went to /dev/null ? (without any error log…)

I’m tried this in 3.7 (today i upgraded mt), in two way:
First:

add name=local-pac code=252 value=”http://192.192.192.113/proxy.pac”

Second:

add name=local-pac code=252 value="0x687474703a2f2f3139322e3139322e3139322e3131332f70726f78792e706163"

Each time i got the same: no option code was sent by Mikrotik!

Please help me, i don’t wanna migrate back to the old system.

7

you think it’s a bug? write support@mikrotik.com

8

OK, i did it. I get an email: new ticket has been created :slight_smile:

I hope they answer me.

Peter

9

ROS version ?

10

3.9

11

Was the same problem with opt 242, until 3.0rc14, where
fixed bug - dhcp server failed to give out options with code > 127;
This also should be fixed in 2.9.51.

May be it’s a new bug ?

12

I read that : fixed bug - dhcp server failed to give out options with code > 127;

But i think, this is a new bug :slight_smile:

13

Mikrotik as a DHCP server and linux as DHCP client. DHCP server gave out option 252 so it can’t be ROuterOS bug.

14

The problem solved by Mikrotik developers.

Thanks for that!

I think, this will be in next release.

ps: mrz: that was a bug.