About the Caltech Network

Caltech Network At A Glance

Caltech's single campus of approximately 130 buildings stretching over 124 acres includes a network system consisting of:

  • Extensive utility tunnel system providing distribution for fiber plant
  • Cat 5 cabling, or better, in all buildings
  • More than 27,000 network jacks 
  • More than 36,000 switch ports
  • Approximately 1,000 network infrastructure devices
  • Approximately 700 wireless APs
  • 237 wiring closets

Caltech's Connections to the Internet

IMSS Network Services includes managing Caltech's participation in state and national computer cooperative networking projects such as:

IMSS also provides Remote Network Access to the Caltech network for off-campus Internet access for Caltech faculty, staff, and students who are eligible for access.caltech accounts.

News Update (3/14/11)

Effective March 21, 2011, the Caltech DNS servers will be reconfigured to disallow recursive lookups from non-Caltech hosts. Currently, our DNS servers are open to all recursive lookups. Recursive lookups allow non-Caltech hosts to perform name lookups (name resolution, or resolver) of non-Caltech names--domains for which we are not authoritative. This can be used maliciously to create or amplify attacks against other networks and/or hosts. Additionally, it drains resources and responsiveness from our own servers.

After March 21, recursive requests will be allowed for internal hosts only, as the host stacks are often not sophisticated enough to perform necessary recursive resolution themselves. Additionally, DNS servers operated by other campus groups that allow open recursion will be blocked from our DNS servers until they are reconfigured. We are making this change to comply with network operations and best security practices. A recent internal IT audit performed on CEFCU has also identified this as a vulnerability to be addressed.
While most people should not be affected by this change, some users may have DNS configurations on their computers that will need to be corrected. Systems should not be configured statically to use Caltech name services while traveling; systems should be configured to use the name services provided in the DHCP responses issued by local network operators. If you encounter any network issues while working off campus, please contact the Help Desk (626-395-3500, http://help.caltech.edu (request type IMSS-->Network, Wireless & Remote Access-->Cannot connect to-->Campus Resources from Outside)) for assistance.