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NetDB is a Stanford University database application that stores Network and Node configuration information. It is generally used by local network administrators and IT Services staff. Most commonly, NetDB is used to assign a new IP address to a computer or printer. The information in NetDB is loaded into two important network services at Stanford: DNS and DHCP.
DNSDomain Name Service
DNS is the network service that maps internet names to IP addresses. For example, a machine looking for forsythe.stanford.edu would request forsythe's IP address. One of the DNS servers would return this address, based on the NetDB entry for forsythe.stanford.edu.
Note that there are two special domains- .sunet and .NoDomain. Names in the .sunet domain are only resolved for Stanford hosts. This is useful for hosts on private address spaces (not reachable from the Internet). Names in the .NoDomain domain are never resolved by DNS servers- they are typically used as placeholders.
If a node has multiple IP addresses, DNS will return all IP addresses in random order. If the DNS request comes from the same network as one of the IP addresses, that address will be returned first in the list.
For reverse lookup, the name closest to the address will be returned first. In other words, the order is IP address name, interface name, node name. In the case of multiple node names, names are returned in random order.
For information about DNS update times, please see DNS Update Information.
DHCPDynamic Host Configuration Protocol
DHCP is the network service that maps hardware addresses to network configuration information. If a machine is configured for DHCP or BOOTP, during network startup, it will send its hardware address and make a request for information called DHCP options. The information returned is based on the NetDB entry for the Node associated with that hardware address. For more information, see DHCP and Bootp.
DHCP information is updated from NetDB approximately every 10 minutes.
NetDB Basic Operations
NetDB users can perform several basic functions, depending on their access rights.
- Search for records
- Quicksearch (name, IP address, hardware address and record type)
- Fullsearch (search for node or user records using any field)
- Create a new record
- All records can be created from the NetDB home page.
- Users will only see those record types that the user can create
- Modify an existing record (often abbreviated as "Mod")
- First search for record. Then click on Modify link.
- Delete an existing record (often abbreviated as "Del")
- First search for record. Then click on Delete link.
- Use an existing record as a template for a new record(often abbreviated as "Tmpl")
- First search for record. Then click on Use as Template link.
NetDB Record Types
There are 6 basic record types in NetDB:
- Node—a networked device (computer, router, printer, hub)
- Network—collection of address spaces
- Admin Team—group of people who administer nodes
- User—user of NetDB application
- Domain—Internet domain like stanford.edu, stanford.org
- Group—access group used for security