Technical Description of our Network

Internet Service Providers and Infrastructure

Our commodity internet bandwidth (currently 1GBit) is purchased through Windstream, while our academic and administrative bandwidth is purchased through the University of Massachusetts. Connectivity between colleges is provided by the 10-gigabit Five College fiber-optic network, linking all five campuses in a ring with a single run out of that ring to 1 Federal Street in Springfield. Should that connection fail, we also have connectivity north from the University of Massachusetts through Keene, NH and then to Portsmouth. Each campus has a redundant connection to this ring. At Hampshire, we have one connection in the basement of Cole, and one in ASH.

Hampshire's Network

Hampshire's network is a star topology, centered in the basement of Cole. Our core is a 6509-E with all DFC-enabled cards and Sup720's. In general, buildings are connected to the core with gigabit or ten-gigabit fiber, and have a layer 3 OSPF networking device with an associated VLAN and subnet. This is to increase resiliency, keep traffic local as much as possible, and reduce the size of the broadcast domains on campus. For security and IP conservation reasons, all of these addresses are RFC1918's that get translated at the edge of our network into a /21 of globally-valid addresses. All connections made concurrently by a single IP inside our network are mapped to the same IP outside, and your translation is reserved for 30 minutes. When we run out of addresses, all subsequent connections are made using PAT through a single address that can support over 65,000 concurrent connections, with an overflow address that can support another 65,000.

We have a ten gigabit physical connection to each of the other four institutions in the Five College Consortium, through the Five College Fiber Network. Any connection initiated from on campus to any of the other four colleges will get routed over this link, meaning we get gigabit speeds between the institutions on the Five College Network. We have firewalls at the edges of our network, one on each link, that perform firewall and NAT functions. These units are currently Cisco ASA5520/5550's.

The bandwidth shaper on the Paetec link is a NetEqualizer NE3000. It shares bandwidth equally among IP's currently asking for it by delaying top users' packets in units of 1/1000 of a second when link utilization nears saturation. It also limits the number of concurrent connections each IP can use.

The College maintains several L2TP/IPSec VPN concentrators for faculty, staff, and student access from remote locations.

The College also maintains both PBXes and Voice-over-IP PBXes for telecommunications.

Wireless Networking

Hampshire's wireless network is powered primarily by H3C 2620/2620E (a/b/g/n) Access Points at various locations around the campus, ensuring connectivity in all public areas of the campus, as well as all of the dorm areas. Merrill, the library, and some parts of Enfield have Ubiquiti 802.11ac access points, and FPH has Aerohive 802.11n units. Some high-concentration areas on campus such as the Airport Lounge, the RCC Gym, and the lecture halls in FPH have Xirrus wireless arrays. Academic areas have three separate networks:

• hampguest (public) This network does not require a login and has an entirely separate connection to the Internet. In this way, it is like sitting in an internet cafe - you are not really on Hampshire's network while using this wireless network, and as such cannot access anything that is on-campus only, and on-campus services will be slower than when using wallace or the dorm networks. This network is only available in the public areas of campus. Students should register their guests' computers under their names if they have guests that need access in the dorms. In this way, you are taking responsibility for the actions of your guests on our network.
• wallace (private) This network requires a Hampshire login, and provides full, direct access to on-campus services for faculty and staff.
• gromit (private) This network requires a Hampshire login, and provides direct access to on-campus services for students. The only difference between wallace and gromit is who can log in, and there are a few services that students cannot get to.
• eduroam (private, encrypted) This is a global roaming network provided by many hundreds of institutions worldwide, and anybody at any of those member institutions can log in at any of the others. Sign in with (username)@hampshire.edu and your Hampshire password. This network is available in academic areas, Merrill, and some of Enfield. It is likely to be available in more dorms soon; it is following the deployment of 802.11ac in the dorms.@hampshire.edu>

In the dorms, the network name matches the housing area, and requires a Hampshire login such as wallace. For instance, in Merrill, the network name is "merrill".

IP Ranges

Hampshire College's public-facing IP ranges are as follows:

• 64.254.160.0/20 (Various)
• 74.8.88.0/22 (Commodity Internet through Windstream)
• 66.251.24.0/22 (Commodity Internet through Windstream)
• 192.33.12.0/24 (IT Servers)
• 192.101.188.0/24 (Academic Servers)

Internally, we use RFC1918 addresses for all end-user devices.

Future Projects

• Full 10 gigabit backbone (in process)
• 802.11ac everywhere (in process)
• IPv6 Deployment