NETS header NETS Homepage UCAR Homepage NCAR Homepage CISL Homepage NETS Homepage About NETS Work requests & support
 (what is this?)
Search NETS pages (excludes internal pages):

NETS Reserved Address Standard - 03/19/14


This document provides guidelines for the gateway and router addresses defined for each subnet. Having a standard to follow eases troubleshooting and general network management.

NETS uses Hot Standby Routing Protocol (HSRP) as one way to improve network availability. This protocol provides network redundancy by ensuring that user traffic immediately and transparently recovers from first hop failures in network edge devices or access circuits.

HSRP works by sharing an IP address and a MAC (Layer 2) address with two or more routers, allowing a group of routers to act as a single 'virtual' router. The members of this virtual router group continually exchange status messages. This allows a secondary router to assume the routing responsibility if the primary becomes unavailable. Hosts continue to forward IP packets to a consistent IP and MAC address, and the changeover of devices doing the routing is transparent.

For more information on this topic
http://www.networksorcery.com/enp/protocol/hsrp.htm

Some existing subnets use 'grandfathered' addresses. All new subnets will be created using this standard. Documentation of the defined gateway for specific subnets is found on the vlans and subnets pages.

NETS reserved addresses

For the purpose of routing, NETS reserves the following addresses within each /24 subnet:

If these addresses are not available, NETS will work with the division to determine appropriate settings. The router addresses will then be documented on the vlans and subnets pages.

Other addresses in a subnet with specific functions:

Router DNS entries

NETS also requests DNS entries for these addresses using this convention:

(campus)router-n(subnetnumber).ucar.edu

These examples are for a subnet on the Mesa