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DNS FAQ Questions
What is DNS? Answers
DNS, Domain Name System, is a set of protocols and database definitions. It is
a distributed system that translates human readable hostnames to network readable IP
addresses. It is comprised of nameservers, resolvers (clients), and many, many
many records. For more information on DNS see: How Domain Name Servers Work A computer user types a URL (including a webserver's name) into his or her web browser. That user's computer must translate the webserver's name into an IP address before it can try to connect to the web server. A 'resolver' or DNS client software on the user's computer asks its DNS server for the webserver's IP address. If the nameserver knows the answer (either it is in its cache or it is the nameserver responsible for that domain), it returns the IP address immediately. If not, the nameserver begins a recursive query to find the address. This query begins with the Internet root nameservers and involves following "Start of Authority" records through a hierarchical organization (root, top-level domain, e.g. "edu", site, subdomain, etc.) until the answer is found. The nameserver returns the IP address and caches all information learned along the way, in case other clients want the same or similar information. What is my IP? subnet? gateway? CNS Customer Service can provide information on data connections via the Data Network Connections Download page, (https://sagebrush.berkeley.edu/cgi-bin/ws515/dncb-rpt.r). Once you log in with your CalnetID, if you have permission to view information for your department, you can download a report of your data connections. If you do not have permission to view data information for your department, contact the authorized representative(s) for your department, (a list is available from that page), and they can provide the necessary information. What DNS configuration should I use?
You can configure your DNS settings to use one or more of these IP addresses
as the campus nameservers: How do I find out which IP to use? When your network connection was installed you (or someone on your department) should have received and email listing the IP address, default gateway, subnet mask, and DNS nameservers you should use for your connection. If you do not have this information, see "What is my IP?" to look up the necessary information. Your ISP will either provide IP and DNS information to you dynamically as you connect, or should have provided that information to you when your service began. Many ISPs provide DNS service and you can configure your at home connection to use that nameserver or campus nameservers. Contact hostmaster@nic.berkeley.edu. Please provide the alias and the hostname to which it will resolve. Unless your department has a special "private network" agreement, IPs are assigned at installation, as part of the CNS work-order process. If you are requesting "extra" IPs please see UCB DNS Policy, particularly section III, C., 3, and contact hostmaster@nic.berkeley.edu. Departments with private networks, the designated contact for the network can contact hostmaster@nic.berkeley.edu. In the UCB DNS Policy, it says that 'Hostnames are normally registered for immediate use. However, hostnames that meet the requirements of this section (III, C., 3) may also be registered in order to "reserve" them, either for future use or to prevent their use by others.' The 'reserved' name should be an alias of a hostname record belonging to the requesting department. What do I do if someone is "borrowing" my IP? Open a trouble ticket by calling 510-642-8500, or by sending email to trouble@berkeley.edu, and ask that a network trouble ticket be opened. Please provide the IP address, the MAC address of the "borrowing" machine, if available, and the cable ID for your connection. Network engineers will respond and attempt to locate the borrowing connection. For more information on filing trouble reports Trouble Reporting. How can I check the correctness of my hostname/IP? Some services will do a reverse DNS check on incoming connection requests. In order to pass your IPs forward and reverse DNS must match. WSS provides a website http://www-uclink.berkeley.edu/cgi-bin/check_anydns.pl, that you can use to check a DNS entry. Or you can use your favorite DNS resolver utilities, such as nslookup, host, dig, etc. How do I lookup data connections not in my department? Due to (mostly physical) security concerns, that information is only provided to authorized representatives of a given department, and only for that department's connections. If you need information about a particular connection outside of your department, you should contact the authorized person in that department. To find authorized representatives see Viewing Connection Information. Contact your departmental IT manager to see if there is a departmental webserver appropriate for your site. Or contact the OCF, www.OCF.berkeley.edu. The OCF hosts virtual websites on their server. Can I have hostname foo.berkeley.edu? Yes. Hostnames are provided on a first-come-first-served basis. Hostnames are generally assigned as part of a CNS work-order (installation). Requests to change a hostname or add an alias can be sent to hostmaster@nic.berkeley.edu. Can I have subdomain foo.berkeley.edu?
Subdomains are assigned to organizational units within UCB. See
Subdomains and Web Servers
Of course. If you wish it to resolve to a UCB IP address, see the next
question.
Can I have a UCB IP resolve to a non-UCB hostname?
Departments may make such a registration without CNS intervention, as long as:
Can I have a UCB hostname resolve to a non-UCB IP? Hostnames in Berkeley.EDU may resolve to non-UCB IP addresses only under exceptional circumstances. To request an exception, contact the IST Policy Office, policy@uclink.berkeley.edu. How can I obtain Berkeley.CA.US domain registrations? UC Berkeley no longer provides support for Berkeley.CA.US registrations. Contact support.us@neustar.us.
Last revised:
June 01, 2009 |
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