Switch interface eases life for novice admins

Switch interface eases life for novice admins

The Catalyst 3550-24 keeps a big network running smoothly with easy-to-use administrative functions.

Administrators of all experience levels will find something to like in this setup

The Catalyst 3550-24 Intelligent Ethernet Switch from Cisco Systems Inc. works well at multiple levels of enterprise networking.

As an access-level switch, the 3550-24 has 24 10/100-Mbps ports plus two Gigabit Ethernet Interface Converter ports. But it also plugs the administrator into higher-level functions such as quality of service, rate limiting, multicast management, access control and high-performance IP routing'all through a Layer 2 management interface.

To measure the switch's performance under load, the GCN Lab used the WebAvalanche test system [GCN, Feb. 4, Page 32] from Caw Networks Inc. of Santa Clara, Calif., which can simulate up to 1 million simultaneous connections.

On the other side of the switch, we placed Caw Networks' WebReflector to simulate the data clusters and servers accessed by our virtual users. We tested only the 10/100-Mbps ports, leaving the Gigabit Ethernet ports for a forthcoming review of stackable switches.

Our first test involved sending 3.5 million 1K packets through the switch'nowhere close to its maximum capacity, but we were measuring accuracy. Of the 3.5 million packets, only three were dropped, and port load never rose above 10 percent.
When we inspected the test results, we saw that the three packets, which were statistically insignificant anyway, were lost because of physical-layer problems. In other words, some of our old Category 5 cables had a few kinks in them.

The second test was a little harder on the switch and more representative of real network traffic. We simulated a 512K object that the imaginary users were trying to grab. We boosted the traffic incrementally in each minute of the 10-minute test. At peak, the switch was processing 316M of inbound traffic and 13M of outbound traffic. We had replaced the cabling, so there were no dropped packets and no collisions.

Even if the 3550 were only a Layer 2 switch, its management interface was impressive. We found it downright revolutionary to be able to set up higher-level functions with a wizard program and a browser interface.

For example, to add security to the communications setup, we simply clicked on the security button in the browser and excluded certain types of traffic or set other parameters. It was no more difficult than installing a new program under Microsoft Windows.

After setting blanket policies with the wizard helper, we could then modify them as needed for different users, ports or packet types.

The only problem we encountered was that the Java-based interface tended to conflict with active virus-scanning software. It's best to disable virus scanning while using the management functions.

Console jockeys will find some improvements in the command line structure, too. The Range command, for example, lets you configure one switch port exactly as you want it, then replicate the configuration across all 24 ports. That's quite a change from the usual situation where each port requires individual configuration'a tedious task for large setups.

The interface displays other clusters on the same network, and you can see details such as cluster name, IP address, cluster manager, and links into and out of the cluster. That's all useful information when you're configuring a communications hub.

The intelligent Catalyst 3550-24 switch will give administrators more free time plus the advanced functions that are increasingly necessary to maintain a smooth-running enterprise network with burgeoning traffic and oversubscribed bandwidth.

About the Author

John Breeden II is a freelance technology writer for GCN.

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