How to Identify Dynamic DNS Frames (186346)
The information in this article applies to:
- Microsoft Windows 2000 Server
- Microsoft Windows 2000 Professional
This article was previously published under Q186346 SUMMARY
Windows 2000 includes the ability for client computers to register
Domain Name System (DNS) records automatically with DNS servers configured
to accept these updates.
MORE INFORMATION
The following sample captured network frame indicates that the frames are
client computer requests to dynamically update the DNS server.
DNS: 0x1B:Dyn Upd UPD records to MYSERVER.mycorp.com. of type Host Addr
DNS: Query Identifier = 27 (0x1B)
DNS: DNS Flags = Query, OpCode - Dyn Upd, RCode - No error
DNS: 0............... = Request
-----> DNS: .0101........... = Dynamic Update
DNS: .....0.......... = Server not authority for domain
DNS: ......0......... = Message complete
DNS: .......0........ = Iterative query desired
DNS: ........0....... = No recursive queries
DNS: .........000.... = Reserved
DNS: ............0000 = No error
DNS: Zone Count = 1 (0x1)
DNS: Prerequisite Section Entry Count = 0 (0x0)
DNS: Update Section Entry Count = 3 (0x3)
DNS: Additional Records Count = 0 (0x0)
DNS: Update Zone: mycorp.com. of type SOA on class INET addr.
DNS: Update Zone Name: mycorp.com.
DNS: Update Zone Type = Start of zone of authority
DNS: Update Zone Class = Internet address class
DNS: Update: MYSERVER.mycorp.com. of type Host Addr on class Req.
for any(2 records present)
DNS: Resource Record: MYSERVER.mycorp.com. of type Host Addr
on class Req. for any(2 records present)
DNS: Resource Name: MYSERVER.mycorp.com.
DNS: Resource Type = Host Address
DNS: Resource Class = Request for any class
DNS: Time To Live = 0 (0x0)
DNS: Resource Data Length = 0 (0x0)
This frame also includes the record to be written:
DNS: Resource Record: MYSERVER.mycorp.com. of type Host Addr
on class INET addr.
DNS: Resource Name: MYSERVER.mycorp.com.
DNS: Resource Type = Host Address
DNS: Resource Class = Internet address class
DNS: Time To Live = 1200 (0x4B0)
DNS: Resource Data Length = 4 (0x4)
DNS: IP address = 100.2.0.3 ---> example IP address
The version of Microsoft Network Monitor included with Windows 2000 Server
parses these frames correctly and displays Dynamic DNS update frames.
If you are using a third-party version or an earlier version of Network
Monitor, you can identify Dynamic DNS update frames by the four bits in
the "DNS Flags" section of the frame, as in the following example:
DNS: 0x17:Std Qry for mycorp.com. of type SOA on class INET addr.
DNS: Query Identifier = 23 (0x17)
DNS: DNS Flags = Query, OpCode - Std Qry, RD Bits Set, RCode - No
error
DNS: 0............... = Query
-----> DNS: .0101........... = Reserved (a value of 5 (0101) here =
Dynamic DNS Update Record)
DNS: .....0.......... = Server not authority for domain
DNS: ......0......... = Message complete
DNS: .......1........ = Recursive query desired
DNS: ........0....... = No recursive queries
DNS: .........000.... = Reserved
DNS: ............0000 = No error
This frame also includes the record to be written:
DNS: Authority Section: MYSERVER.mycorp.com. of type Host Addr on
class INET addr.
DNS: Resource Name: MYSERVER.mycorp.com.
DNS: Resource Type = Host Address
DNS: Resource Class = Internet address class
DNS: Time To Live = 3600 (0xE10)
DNS: Resource Data Length = 4 (0x4)
DNS: IP address = 100.2.0.3 ---> example IP address
NOTE: Specifications for Dynamic DNS are found in Request for Comments
(RFC) 2136. For information about obtaining an RFC document, please see
the following article in the Microsoft Knowledge Base:
185262
How to Obtain Request for Comments Documents from the Internet
| Modification Type: | Major | Last Reviewed: | 2/24/2004 |
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| Keywords: | kbhowto kbnetwork KB186346 |
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