Dell Powers Its Way Into Higher Density, Managed Switch Connections

The 3248 isn't the first switch for Dell, which started selling switches in 2001, namely a 24-port 10/100 switch, the 3024, and the 5012, a 12-port Gigabit copper switch. These original switches have a different user interface from that of the 3248.

Double the Density

Dell's new switch rounds out the product line nicely, providing twice the port density as the 3024 in the same 1U rack space. It also packs in features not found on the 3024, such as Layer 3 QoS (Quality of Service) based on ToS (Type of Service) or DiffServ bits, as well as QoS based on TCP/UDP port. It also adds an option for an external redundant power supply as well as the ability to maintain multiple firmware images, so you can back out of an unsuccessful firmware upgrade much more quickly.

The 3248 is easy to set up and a breeze to monitor. The status LEDs are lined up along the top of the switch, above the cabling, for visibility. The lights can be toggled to indicate duplexity or speed. Two copper Gigabit uplink ports, which can be easily converted to fiber via the mini GBIC slots provided, are also included.

I used two Spirent Communications SmartBits 6000B testers to load up all 48 of the 100-Mbps ports and the two Gigabit ports. I blasted 100 percent utilization on every port with 64-byte frames, 1,518-byte frames and four sizes in between. The 3248 didn't drop a single frame, proving its claims of true wire speed performance on every port at once. I ran another test that created unique MAC (Media Access Control) address entries in the bridge table to test Dell's claimed ability to support 8,000 unique entries. The switch passed this test with flying colors with an actual total of 8,187 unique entries. I also used the SmartBits to test latency at each packet size while running at 100 percent utilization on every port. The median latency for 64-byte packets was 27 microseconds. For 1,518-byte packets, it was 55 microseconds, low enough to be insignificant.

The switch can be monitored and configured with the CLI (command line interface) via telnet or the serial port. While it was very similar to Cisco's CLI, it was different enough to be confusing at times. For example, saving the configuration required using a copy command, which is very different from the way Cisco does this. I was glad to see that the up arrow repeated a history of previously edited commands, just as with Cisco's IOS. And unlike some switches, the 3024 let me navigate on the IOS-style CLI without any difficulty while the test was running.

The Web-based management application makes it easy to gather statistics and query the switch. Expandable menus appeared in a panel on the left side of the main Web window. Using these menus to configure functions such as priority queues and VLANs was easier than it would be with the command line. Another nice feature allowed me to use the Web interface to search for a MAC address and its corresponding port. The Web interface made it possible to change the IP address of the switch and load firmware images.

This switch does have limitations, however. I was able to check performance statistics on the command line or Web only one interface at a time. It would be a lot easier to track down performance issues if you could display a summary table of statistics, as you're able to do with some Cisco switches.The switch also comes with SNMP management capabilities, which could let you summarize statistics better than on the CLI or the Web interface. The switch also supports MIB2, so it could easily provide summarized statistics via a MIB2 network management product. Dell plans to include support for the 3248 in the next version of its OpenManage element manager later this year to provide better management.

This switch is best-suited for existing or future Dell PC customers that have smaller networks. Such customers can now simplify their vendor interactions by buying their switches and PCs from the same place. The price is right, and the performance is stellar.

Peter Morrissey is a full-time faculty member of Syracuse University's School of Information Studies, and a contributing editor and columnist for Network Computing. Send your comments on this article to him at [email protected].