Full Resolver Provision
The Network Systems Group provides DNS servers (full resolvers) for on-campus use.
A full resolver is a server that performs name resolution and returns responses to requests from DNS clients. It is the DNS server that DNS clients (most hosts other than DNS servers themselves) specify in order to resolve names on the Internet.
The Network Systems Group provides two full resolvers. They are geographically distributed, so that both full resolvers do not go down at the same time.
| Location | IP Address | Host Name |
|---|---|---|
| Ookayama Campus | 131.112.125.58, 2001:200:136:2::53 | ns-o.noc.titech.ac.jp |
| Suzukakedai Campus | 131.112.181.2, 2001:200:136:4001::53 | ns-s.noc.titech.ac.jp |
For load balancing, users on the Ookayama and Tamachi campuses should configure their systems to give priority to 131.112.125.58, and users on the Suzukakedai Campus should give priority to 131.112.181.2.
The above full resolvers also provide information for domains and records that are valid only within the Institute of Science Tokyo. Examples of information valid only on campus include the names of servers operated under on-campus private addresses, and reverse lookups for on-campus private addresses. For this reason, please note that some servers cannot be reached unless you specify the above full resolvers, because their names cannot otherwise be resolved.
Frequently Asked Questions
Why does this page refer to DNS servers as "full resolvers"? Wouldn't "DNS server" be sufficient?
DNS servers can be broadly divided into two types.
One is the "content server" (also called an authoritative server), which provides information for the specific domains it manages (for example, titech.ac.jp). The other is the "full resolver" described on this page. A full resolver is also called a "cache server."
Although these are two different types of DNS server, traditionally it has been common to operate a single DNS server that performs both the content server and full resolver roles, and both are simply called "DNS servers." As a result, the two are often confused, and we frequently see cases where settings are not configured appropriately. For this reason, this page explicitly uses the term "full resolver."