Other pages in the review
Seven years ago Gigabit Ethernet networks began to emerge across businesses, but still some computers continue to ship with restrictive network cards. Take last month’s low-cost desktop review for example. We received a Lenovo product with only a 100Mb network card on board. Thankfully, the majority of machines, as you move beyond low cost, now ship with Gigabit network cards as standard.
Switches for Gigabit networking are now commonplace, and the frontier of switch technology is in the fibre channel 10Gb realm, most businesses retain Gigabit Layer-3 switches as the core of their infrastructure and it seems likely that this will continue in the future.
This month we take a look at 1RU Layer-3 switches. Routing, or Layer-3 processing, is required when traffic needs to be taken across subnets. If your network operates on a single subnet there is no benefit in having a Layer-3 switch as no routing is involved. If you do need to work across subnets, Layer-3 switches or routing switches, are a higher bandwidth alternative to using a Layer-2 switch and a router. Although Layer-3 switches possess most of the features of a stand alone router, they cannot be used as a replacement as they don’t perform some of the more complex routing features that stand alone routers do.
The difference between Layer-2 and Layer-3 switches is the way network packets are looked at and forwarded to other computers on the network. Layer-2 switches work at the data layer and only switch using Mac address information. This limits traffic to the subnet which the computer is on. If packets need to reach a different subnet a router (which is also a Layer-3 device) can forward packets. Layer-3 switches, however, look at the network layer and store tables of network IP addresses. This gives the switch similar functionality to a router, meaning it can pass packets between subnets.
In this review we will look at switches from Nortel, Alloy, HP and D-Link. We invited 3Com, Extreme and Cisco to participate but they declined.
Cisco has been the market leader in this area for some time now. Market research from Gartner shows that Cisco leads in market share for both the number of ports and revenue made. Netgear and HP ProCurve follow in second, respectively, with D-Link and Nortel closely behind.
Interestingly, according to Infonetics’ market research, Cisco’s price-to-performance rating has dropped over recent times—this could be a threat to future sales. Infonetics also predicts, however, that existing users of Cisco equipment will generally stay with Cisco to maintain interoperability. But whichever way you look at it Cisco remains in a strong market position for now.
After discussing with a few network administrators why Cisco is currently the market leader in networking equipment, the general opinion is that while Cisco is expensive the features and flexibility of Cisco’s router and switch operating system is difficult move away from when compared to what other vendors have to offer.
Detailed rules can be set up to shut down ports when certain conditions are met, such as when another switch or router is connected, when someone on the network tries to operate a DHCP server or something as simple as when someone is trying to use a prohibited protocol. Reliability is also another compelling factor. There are claims that some Cisco switches are in excess of 14 years old are still operating without a hitch. Cisco switches do cost a premium and prices are in excess of $17,000 compared to $12,439 for the HP ProCurve, the most expensive switch in this review.
All switches tested support the fundamental protocols you would expect from a Layer-3 switch, including VLAN tagging, spanning tree, link aggregation and Web configuration, but only HP ProCurve and Nortel’s products come equipped to deal with Power over Ethernet (PoE).
VLAN tagging is a feature where switches tag traffic with a small amount of information about how that traffic should be dealt with. This can be read by any VLAN tag-aware switch. Spanning tree is a protocol that monitors and polices loops in network connections. If you loop switches together, you create a broadcast storm from looping packets that could corrupt the switches location table and possibly cripple the whole network. Link aggregation is a fancy term for port trunking, where switches can use multiple ports to trunk to other switches providing more bandwidth between them.