Network Connectivity FAQ

1. What caused the network outage that began around 2:00pm on Tuesday, October 29, and continued through Wednesday, October 30, until about 1:00pm? Was the failure caused by re occurrence of problems with the Internet-2 router – similar to those experienced in mid-September?

The most recent network outage was caused by the total failure of the Cabletron SmartSwitch/Router that serves as the central point of connection for the building wiring closets. The problems associated with the Internet-2 router appear to be resolved.

2. Why did this failure cause a campus-wide network outage?

All the building wiring closets connect back to the server room through a port on the SmartSwitch/Router. As such, it is a single point of failure on our network.

3. Why don’t we have a second or redundant device to prevent such a failure from impacting the entire network?

Primarily due to cost of about $138,000 for the device as configured

4. Do we have a maintenance contract on the device?

Yes and no. We have budgeted $43,000 for Cabletron maintenance. Knowing that the Cabletron device lacked some of the features we needed to implement a secure wireless network, we used those funds (and a bit more) as the initial payment on a three-year lease of a Cisco 6500 switch/router. In this case, continuing maintenance on the Cabletron device would not have reduced the network downtime, so severe was the failure.

5. So where is the Cisco device? Has it been installed?

The Cisco Switch had been delivered to InterTel in Sioux Falls. Last week a Cisco technician was on campus collecting information necessary to configure the switch – especially the intrusion detection components. The original plan was to schedule implementation early on some Thursday, which is our regular maintenance time. The total failure of the Cabletron switch has provided the “opportunity” for an immediate installation. The Cisco switch/router was installed on Wednesday morning.

6. What is being done with the Cabletron SmartSwitch/Router?

Now that we have the network operating again, we can determine what failed and attempt to repair the device. If it can be repaired it will become our backup central switch/router.

7. Has the Cabletron device been failing for a while? Is that why the Cisco device was ordered? Has that been the cause of the slow network access in the dorms?

While the Cabletron device has had its operational peculiarities, we ordered the Cisco device primarily for the extra features that would protect the wireless network, support local multicasting traffic, and provide internal intrusion detection services. The speed of network response in the dorms is a function of the peer-to-peer applications students are running on their personal machines.

8. Isn’t DSU an ISP? Dorm students are paying $60 per semester for their connection. Shouldn’t they expect better service?

DSU is not an ISP. The network is established and managed to support academic activities in accordance with the Computing Privileges Policy (see it here (ps – you can click this)). The fees collected are utilized to fund the switches and support services for the network in the dorms. The $60 per semester equates to $15/month. This is the approximate cost of a limited access dial-up connection. In keeping with the academic focus of the network, connectivity in the dorm provides a way for students to quickly and easily access local resources. Better access will naturally result when dorm residents cease running peer-to-peer applications.

9. What are the “peer-to-peer” applications students are running on personal machines in the dorm?

Examples of peer-to-peer applications include: KaZaA, Grokster, Morpheus and others. These applications provide opportunities to retrieve or share music, movies, software, video games and other copyrighted materials without authorization. In addition to consuming bandwidth for non-academic purposes, these applications raise issues of copyright infringement and open personal machines to virus attacks. While there are legitimate uses for peer-to-peer applications, the bulk of the peer-to-peer traffic appears to support entertainment, not academic, activities.

10. Aren’t these the same applications DSU was attempting to block last year? This year it appears only the dorms are impacted. Why is that?

Last year DSU attempted to block each application through its standard “port”. But students would configure the application to use another port and by-pass the network management rules in place on the PacketShaper®. This year, rather than attempting to block or limit each application, we’re limiting the bandwidth to the dorm subnets to 6M – about 75% of our 8M Internet connection – at priority level 0. The rules as implemented provide first priority to network traffic for labs and offices. For example, if the labs and offices require 6M of network connectivity, the dorms will be limited to 2M; if the labs and office require 4M of network connectivity, the dorms will be limited to 4M; if the labs and offices require no network connectivity, the dorms will be limited to 6M. This network management approach has certainly reduced the complaints from faculty and staff concerning network access.

11. Can’t DSU determine which students in the dorms are running these applications and stop them so students with legitimate academic needs would not be impacted?

With the PacketShaper® we can identify those machines that are consuming excessive bandwidth. Rather than establish a “bandwidth police” unit, we would prefer that students accept the responsibility to utilize the network in appropriate ways. This does not preclude future steps to ensure ethical and reasonable usage of network resources.

12. Who is more stupid? Beavis or Butthead?

Son – that is for YOU to decide.

¿@Beavis or [email protected]?

6 Replies to “Network Connectivity FAQ”

  1. this is a good post, interesting to read. Beavis was always following Butthead, so this would lead us to the conclusion that Butthead was smarter.

  2. That was the most boring thing I have ever seen anywhere. Maybe thats becuase I didn’t understand a word of it, but maybe not.
    Maybe it was boring to everybody.
    You should think about that

  3. yeah, it was the lazy man’s post. “I’ll just copy over this email I got cuz I’m too lazy to write something myself.”


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