Host Configuration

Overview

When configuring your host to connect to the network for the first time, use DHCP. The device will be given an IP address and appropriate settings by default. If you request a static IP from RPI Hostmaster, you will be provided the IP Address, Default Gateway, Subnet Mask & DNS servers to use in an email. 

If your IP address has a format similar to "128.113.n.n, 128.213.n.n, 129.5.n.n or 129.161.n.n" you are on a DotCIO network. If your address begins with "128.113.50.n, 128.113.6[012] .n, 128.113.7[34]" you are on a network supported by ECSE and will need to contact them first for assistance.

If you are a UNIX user and have difficulty configuring your system, please submit an online Support Request.

Details

ResNET (Switched Ethernet)

ResNET is the Switched Ethernet provided to campus residence halls. All traffic from ResNET to the Internet pass thru a firewall. Any traffic between Resnet and the general campus network goes direct. There is no firewall between the general campus network and ResNET. 

The first and second numbers of your IP address -- "128.113" -- are known as the "network numbers". The third number is referred to as the "sub-network number," and the fourth number is the "host number".

You can determine if you are on ResNET by looking at the third number in your IP address. If that third number is listed in the table below, you are on ResNET. Otherwise, you are on the standard RPI network. 

Default Gateway or Router

We use variable sized subnets. Do not assume  your default gateway will always be the same as your host but ending in 254. Record the settings your system was given when using DHCP. That information will be correct for your specific network. The hostmaster will also include this information with any static IP assignment. With a few exceptions most Default Gateways will end in x.y.z.254.

If you are part of ResNET, use the table below to find your Default Gateway Address. For example, the correct gateway for subnet 145 is 128.113.144.254

Sub-Network (Subnet) Mask

Most sub-network mask for machines not connected to ResNET will usuall be 255.255.255. (This may sometimes be specified as "FFFFFF00".) If you are connected to ResNET, use the table below to find your Mask. For example, the correct Mask for subnet 145 is 255.255.248.0. 

Domain Name Server

A number of domain name servers are available on different sub-networks. If there is a domain name server on the local sub-network, use that one as the primary server.

As a general rule, pick from the list below in a random order. 

IPv4

• 128.113.28.68 resolute.net.rpi.edu
• 128.113.26.250 defiant.net.rpi.edu
• 128.113.11.73 reliance.net.rpi.edu

IPv6

• 2620:0:2820:4::9    dns9.net.rpi.edu

NOTE: As of June 2012, systems must use RPI DNS services while on Rensselaer's network. External DNS services such as OpenDNS and Google Public DNS will no longer work.

If there is a domain name server on your sub-network, you should use that one as your primary server. However, your secondary domain name server should be on a different sub-network than the primary. 

Additional IPv6 Information

With the "World IPv6 Launch" which took place during the summer of 2012, as a general rule we now advise users to leave IPv6 enabled, with tunneling disabled. Make sure you disable the tunneling feature.

We encourage those having servers with IPv6 enabled to check their IPv6 firewall settings, as IPv4 settings will not offer proper network protection. Users will also need to check any application settings designed to control access for IPv6 settings.

Users may also use the links below for even more information:

• Instructions for Microsoft operating systems
• An example for Mac operating systems

Please note that users are not required to run IPv6; systems will work fine without it.

Domain Name

The domain name for your host is determined by the fields of the "dotted quad" name after the first field. A typical host name looks like "okeeffe.cis.rpi.edu" this host's name is "okeeffe" and its domain is "cis.rpi.edu". For hosts here at Rensselaer, the last part of the name always ends in .rpi.edu, which may be thought of as the network and the second dotted field, "cis" in this case may be thought of as the "sub-domain". When configuring a host, the term domain usually refers to the entire portion of the hostname after the first field. When a name is specified with all of its parts it is referred to as a "Fully Qualified Domain Name" (FQDN).

Last Reviewed: 25-Jul-2018