DHCP May Register IP Address as Printer Name in DDNS (257600)
The information in this article applies to:
- Microsoft Windows 2000 Server
- Microsoft Windows 2000 Advanced Server
- Microsoft Windows 2000 Professional
This article was previously published under Q257600 SYMPTOMS
When you configure Windows 2000 Dynamic Host Configuration Protocol (DHCP) to update DNS zones for clients that do not support dynamic update, printers may be registered in forward-lookup zones and reverse-lookup zones using their DHCP-assigned Internet Protocol (IP) address as their name. The registrations appear as new child domains identified by numbers beneath the domain in which the printer is registered. In some cases, only the reverse-lookup zone is registered.
CAUSE
By default, most network printers are not configured with a host name. When a printer without a host name receives an offer for an IP address from a DHCP server, it responds with a DHCPRequest packet in which the HOST NAME option field is populated with the IP address offered by the DHCP server. By design, the DHCP server examines the HOST NAME option field to obtain the client name that it registers in DNS. Because the HOST NAME field contains an IP address, this is the name that DHCP registers on behalf of the printer in DNS.
RESOLUTION
To resolve this issue, give the printer a valid host name using an appropriate method. Contact your manufacturer for more information.
MORE INFORMATION
When the printer returns its IP address as a host name, the dots separating the octets in the IP address are correctly interpreted as namespace delimiters, and are registered appropriately. If the printer supports DHCP option 15 (Domain Name) it appends that information on its name and returns that during the DHCP process. Therefore, if the printer's IP address is 172.16.10.100, and its A record is to be registered in the company.com domain, the fully qualified domain name (FQDN) of printer is interpreted as 172.16.10.100.company.com. DNS detects the 100 octet of the IP address as a child domain of company.com, and creates a bucket for that domain beneath company.com. A child domain called 10 is created beneath the 100 child domain, and so on. Finally, an A record for 172, which is interpreted as the individual host name, appears within the child domain named 16.
In the situation where the printer does not support the Domain Name option, it returns only its IP address and the DHCP server attempts to register that. Because there is typically not a zone defined for the last octet of its IP address, the registration process is unsuccessful.
In both cases, the PTR record is registered in the proper reverse-lookup zone.
It is possible that other network devices that use DHCP may behave in a similar fashion.
| Modification Type: | Major | Last Reviewed: | 11/20/2003 |
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| Keywords: | kbnetwork kbprb KB257600 |
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