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DHCP Option 78 with third-party DHCP

Hi

I have a little problem with the Option 78 and a third-party Firewall DHCP.
All clients never receive a SLP IP address.

I have to use the HEX code in this DHCP server.

In option 1 "Code" I put in 78 and in the "Option" the Hex code
3137322e31372e33362e3630 for the IP address 172.17.36.60 but the clients
don't receive this option.

I think the problem is this Mandatory byte!

As I read in the RFC2610, the SLP options have an extra flag in the option
field that is different than any other DHCP option. This flag is called the
Mandatory byte. No other DHCP options for simple address arrays follow this
structure.

The following example compares SLP options to DCHP options:
SLP options:
| Code = 78 | Length | Mandatory | a1 | a2 | a3 | a4 | ...

How do I have to add this extra Mandatory-byte in the DHCP options HEX
string?

I tried to place a 1 in HEX 31 in front of the IP HEX code but without
success.

Can somebody explain me the correct syntax for the option 78?

Thx


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Re: DHCP Option 78 with third-party DHCP

>
> I have a little problem with the Option 78 and a third-party Firewall DHCP.
> All clients never receive a SLP IP address.
>
> I have to use the HEX code in this DHCP server.
>
> In option 1 "Code" I put in 78 and in the "Option" the Hex code
> 3137322e31372e33362e3630 for the IP address 172.17.36.60 but the clients
> don't receive this option.
>
> I think the problem is this Mandatory byte!
>
> As I read in the RFC2610, the SLP options have an extra flag in the option
> field that is different than any other DHCP option. This flag is called the
> Mandatory byte. No other DHCP options for simple address arrays follow this
> structure.
>
> The following example compares SLP options to DCHP options:
> SLP options:
> | Code = 78 | Length | Mandatory | a1 | a2 | a3 | a4 | ...
>
> How do I have to add this extra Mandatory-byte in the DHCP options HEX
> string?
>
> I tried to place a 1 in HEX 31 in front of the IP HEX code but without
> success.
>
> Can somebody explain me the correct syntax for the option 78?
>

rfc2610 can!
pls see fi http://www.networksorcery.com/enp/rfc/rfc2610.txt
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Re: DHCP Option 78 with third-party DHCP

"PetervdM" <peter.van.de.meerendonk@adp.nl> schrieb im Newsbeitrag
news:uJ0Bl.10670$Ht3.5869@kovat.provo.novell.com...
> rfc2610 can!
> pls see fi http://www.networksorcery.com/enp/rfc/rfc2610.txt


Sorry Peter, it may be that I'm a little bit stupid, but it can not,
otherwise i would not written here!


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Re: DHCP Option 78 with third-party DHCP

On 2-4-2009 14:06, Marco Schlegel wrote:
> "PetervdM"<peter.van.de.meerendonk@adp.nl> schrieb im Newsbeitrag
> news:uJ0Bl.10670$Ht3.5869@kovat.provo.novell.com...
>> rfc2610 can!
>> pls see fi http://www.networksorcery.com/enp/rfc/rfc2610.txt

>
> Sorry Peter, it may be that I'm a little bit stupid, but it can not,
> otherwise i would not written here!
>
>

with your example of 172.17.36.60 the string could be:
( 0x means this is hexadecimal notation )
len = 1 ( for mandatory byte ) + 4 ( ip address octets ) =5 -> 0x05
mandatory 0 or 1 -> 0x00 or 0x01 ( you decide )
first octet 172 -> 0xca
second octet 17 -> 0x11
third octet 36 -> 0x24
fourth octet 60 -> 0x3c

i don't know what input syntax is required by your dhcp server, but the
complete string for option 78 would be:

050?ca11243c ( where ? is 0 or 1, depending on mandatory or not )

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Re: DHCP Option 78 with third-party DHCP

>>
> with your example of 172.17.36.60 the string could be:
> ( 0x means this is hexadecimal notation )
> len = 1 ( for mandatory byte ) + 4 ( ip address octets ) =5 -> 0x05
> mandatory 0 or 1 -> 0x00 or 0x01 ( you decide )
> first octet 172 -> 0xca
> second octet 17 -> 0x11
> third octet 36 -> 0x24
> fourth octet 60 -> 0x3c
>
> i don't know what input syntax is required by your dhcp server, but the
> complete string for option 78 would be:
>
> 050?ca11243c ( where ? is 0 or 1, depending on mandatory or not )


Uahh! Great explanation!!! That I would have never solved myself!
I just put a online hex converter and convert 172.17.36.60 into
3137322e31372e33362e3630 !
I apologize that now with my bad English knowledge 😉

Thank you verry much!

Regards
Marco

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Re: DHCP Option 78 with third-party DHCP


Hmm, problem still exists 😞

But now I think the problem is the Novell Client 4.91SP5 and not the DHCP
server, because in the packet sniffer I can see, that the Novell Client only
request the Option 81 and never Option 78.

In the client settigs we have the parameter "Use DHCP for SLP" on and I
think that should be enough for a request the Options 78/79

Where else could be the problem on the client side?

The slpinfo /all output looks like this on the clients:

SLP Version: 4.91.5.2
SLP Start Time: 3:53:17pm 4/14/2009
Last I/O: 3:54:37pm 4/14/2009
Total Packets: Out: 42 In:
Total Bytes: Out: 3134 In:

SLP Operational Parameters Values
------------------------------- ------------
Static Scopes NO
Static Directory Agents NO
Active Discovery YES
Use Broadcast for SLP Multicast NO
Use DHCP for SLP YES
SLP Maximum Transmission Unit 1400 bytes
SLP Multicast Radius 32 hops

SLP Timers Values
------------------------------------- ------------
Give Up on Requests to SAs 15 seconds
Close Idle TCP Connections 5 minutes
Cache SLP Replies 1 minutes
SLP Default Registration Lifetime 10800 seconds
Wait Before Giving Up on DA 5 seconds
Wait Before Registering on Passive DA 1-2 seconds

Scope List Source(s)
---------------------------------------- ------------
<unscoped>

DA IP Address Source(s) State Version Local Interface Scope(s)
--------------- --------- ----- ------- --------------- --------------

<No Directory Agents>

Local Interface 172.17.38.113
---------------------------------
Operational State: UP
Operating Mode(s): MCAST
SA/UA Scopes: <unscoped>
Last I/O: 3:54:37pm 4/14/2009
Total Packets: Out: 42 In:
Total Bytes: Out: 3134 In:
Last Addr Out: 224.0.1.22
Last Addr In: 0.0.0.0


Any sugestions?
Thx
Marco


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