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SCS IP Address Consolidation Information

SCS Computing Facilities is transitioning SCS-specific DNS, DHCP, and IP Address Management services to a common, University-wide system operated by Computing Services. This transition requires us to eliminate cases in which a machine has a single hostname and multiple IP addresses.

Why is there muliple IP addresses on my machine?

SCS has separate network segments for different locations. It may need more than one IP address. For example, if the machine moves between buildings. It is also possible that your machine may have been registered in another building (i.e. on another network) at one time and the old IP address was never removed.

What will happen to my old IP addresses?

When an IP address is not being used, that address will be removed from the machine. This does not mean the machine will no longer be on the network, only that it will not be registered in the building that was using that IP address. If you need an IP address for a difference building please let us know.

Why do I need a different hostname for each IP address?

The School of Computer Science uses separate network segments for a variety of reasons. Sometimes these segments reflect physical location differences. For example, each physical building with an SCS presence has its own network segment. This is why machines that move between buildings, must have multiple IP addresses and corresponding unique hostnames. This system allows machines on wired SCS networks to be assigned static (unchanging) IP addresses.

What is the new name structure for machines?

The standard arrangement is to retain the machine's "real" name for the primary or most-used network. Each additional IP address is then given an alternate name, produced by taking the primary name and appending a suffix identifying the building or other subnet on which that address is used.

  • GHC Public: NAME-GATES.PC.CS.CMU.EDU (128.2.210.XXX)
  • GHC Machine Room: NAME-MRG-FAC.PC.CS.CMU.EDU (128.2.172.XXX)
  • GHC Machine Room Public: NAME-MRG-PUB.PC.CS.CMU.EDU (128.2.220.XXX)
  • WeH Facilities: NAME.PC.CS.CMU.EDU (128.2.193.XXX)
  • WeH Machine Room Facilities: NAME-MRA-FAC.PC.CS.CMU.EDU (128.2.201.XXX)
  • WeH Machine Room Public: NAME-MRA-PUB.PC.CS.CMU.EDU (128.2.204.XXX)