in the answer of DHCP not all parameters ! ( opesuse13.1)

English Network/Internet
#1

OpenSUSE13.1 x86 as DHCP server.

This is from my config:


.....
option ttt code 120 = string;
subnet 1nl92.168.43.0 netmask 255.255.255.0 {
  range 192.168.43.20 192.168.43.100;
  default-lease-time 600;
  max-lease-time 7200;
  option time-servers 192.168.41.152, 172.18.1.4;
  option domain-name "myoffice.ua";
  option ttt "PPPPPPPPPPPPPPPPPPPPP";
  option domain-search "myoffice.ua";
}

For check i`m use tcpdump:


tcpdump -nl -i enp3s2 src 192.168.43.8 and udp -s0 -w/4.pac

Load 4.pac in the WireShark and see in the answer from DHCPD only:
Option 53
Option 54
Option 51
Option 1
Option 15 ( Domain name )
Option 3 ( Router )
Option 6 ( Domain Name Server )
Option 255 (End )

Where is “Option 120” with string “PPPPPPPPPPPPPPPPPPPPP” ?

Serg

#2

Are you able to post your entire DHCP config in a pastebin?
Either of the following would be OK, if there is anything sensitive you can sanitize
http://paste.opensuse.org
http://pastebin.com

In particular, it might be relevant to see the entire option 120 code block without sanitizing, ie. is there a real ttt value?

Also, have you restarted your DHCP service after modifying the configuration? You can do this using YAST, a systemctl command, etc.

TSU

#3

I have never configured a DHCP server, but this loks strange to me:

subnet 1nl92.168.43.0 netmask 255.255.255.0
#4

resend:

 
option ttt code 120 = string;
subnet 192.168.43.0 netmask 255.255.255.0 {
  range 192.168.43.20 192.168.43.100;
  default-lease-time 600;
  max-lease-time 7200;
  option time-servers 192.168.41.152, 172.18.1.4;
  option domain-name "myoffice.ua";
  option ttt "PPPPPPPPPPPPPPPPPPPPP";
  option domain-search "myoffice.ua";
}
  • Yes, /etc/init.d/dhcld restart
  • i`m manual configure /etc/dhcpd.conf ( use vi )
  • “ttt” this is test-option
#5

I have not heard before of a “ttt” test option and I’m not getting any Google hits or info in the dhcp-option MAN pages.
Can you post a reference about using this?

TSU

#6

And why you do not ask where is option time-servers? My best guess is that server returns what client asked for. Also note, that option 120 is reserved by IANA for public options, if you want to define site-specific one you should chose number between 224 and 254.

#7

I believe that DHCP option 120 is supposed to provide clients a network configuration for SIP servers
https://www.rfc-editor.org/rfc/rfc3361.txt

If there is any confusion about that, the DHCP-options MAN pages describes how to specify the option by name instead of by number.

TSU

#8

Then it makes sense it is not returned. I would expect dhcpd to disallow known options redefinition. Logs could tell more.

#9

Ok.
recheck. at this time: http://paste.opensuse.org/35474603

how to check, what dhcp returns in reply to option 120 ?

Serg

#10

Could you attach pcap with complete DHCP transaction between client and server? You could uuencode and upload as text file.

#11

At this time i`m have not real DHCP-HardWareclient for “option-120”.
I now configure the DHCP server under this article : http://tohamey.blogspot.de/

Pac file - http://srv.ami.ua/77uu.bin
( please, manual uudecode and rename to filename.pac )

#12

It does not contain full transaction, only single DHCPINFORM request, but no reply. Was it captured on client or server side?

#13

First,
I assume as stated in your reference you are setting up DHCP to specifically support Microsoft Lync Server (please verify).
Other VoIP systems will most likely support a different way to push SIP Domain and connectivity solutions.

Also, as stated in the documentation for using DHCP option 120 to push a SIP configuration, I assume you know that the purpose is specifically to push the address of the SIP proxy server, which ordinarily is used to traverse NAT (As long as DHCP is being used, other information is being pushed, too but the proxy server location is the most important). This means that…

You should first check to make sure your SIP phones are working internally within the LAN. You shouldn’t need the DHCP information to do this testing. If your phones aren’t working in the LAN first, they won’t work with a more complicated configuration.

I haven’t read up on the Lync server, but I assume that AD is providing directory services for the phone system. Assuming my guess is correct, this needs to also be working.

Aside from the above,
Can you post your entire dhcp.conf to a pastebin? The snippet may not contain all the required information, and may be why the entire file is posted in your reference.

TSU