Some offenders suggest the redundant switch is temporary, and they'll return to properly run additional Ethernet cabling, but that rarely happens. Instead, the client is left with interconnected and undocumented network switches, more unnecessary hops, poor network performance, and additional devices to fail following power outages and lightning strikes.
If you support so many network nodes that multiple switches are required, do it right. Purchase stackable switches designed to work together that scale to match the site's requirements. Cease interconnecting switches via an Ethernet cable whenever possible. Seek switches featuring high-speed stacking ports (such as via an HDMI interface). Then power the switches using a proper battery backup.
The real world
Unfortunately, best business practices aren't always followed in the real world. I've lost track of the number of times my consulting office has inherited a client complaining of intermittent connectivity issues or just plain poor network performance.
On a few occasions I've even been called in to troubleshoot poor performance after the previous IT provider deployed a new and potent RAID 10-, 32 GB RAM-, SSD drive-, and dual-CPU-powered server only to discover performance issues still remained. Following a simple on-site assessment, the cause becomes obvious, at least to a professional.
Frequently I find a network closet with a 24- or 48-port switch. If the client's lucky, the switch is powered by a battery backup. Then I might find a 16-port switch in a corner office that shares a single Ethernet drop with a half-dozen switches and a handful of printers. Then there's a five-port switch hidden behind a file cabinet in the receptionist area and another five-port switch in a nurse's station that shares a single Ethernet cable with a pair of machines and a network printer. Oh, and these extra switches are all plugged straight into surge protectors, too -- there's no battery backup in sight. How surprising.
Every time the power browns out, there's a thunderstorm, the electricity fails for just a fraction of a second, or some other blip occurs, those (and in some cases hidden) switches suffer corrupted memory. Subsequently, certain pockets of the office can no longer connect. Rebooting the main switch in the network closet doesn't fix the problem. Frustration rises.
I've even seen rogue switches hidden behind cubicles built a decade earlier no one knew existed malfunction and flood the network with bad traffic. Try troubleshooting that problem when you can't even physically locate the switch.
Avoid becoming an offender
You should follow best practices and insist on deploying additional Ethernet drops when they're required. Unless you're caught in an incredibly rare case in which the site is a historically registered building and a cable just can't be run, you should run new cabling.
Here's the cost justification: If you don't run new cable and you depend upon daisy-chained connections, trouble will arise -- it's a question of when, not if. This is true even if you go so far as powering the extraneous switches using a battery backup, which helps reduce the number of network failures. Each time a failure arises, the client's going to suffer an outage, which means staff can't work and that translates to lost revenue. Then the client calls you, which results in a service call. Maybe you power cycle a switch or two or even replace one of the extraneous switches that's been fried by a lightning strike, resulting in another $75 in parts and $125 in labor. Consider that scenario may repeat itself three of four times over four or so years, and the client's looking at having lost hours of staff productivity and maybe a thousand dollars in switches and service.
A new cable drop might run $100 or $200, and it will provide a much more reliable network experience. It's simply more cost effective. Clients won't always understand the cost efficiency at first -- that's your responsibility. As a consultant, it's your job to help educate the client and help the client make better, more informed decisions. Point to your years of experience, and then finish with the simple truth: only novices daisy-chain switches.
Erik Eckel owns and operates two technology companies. As a managing partner with Louisville Geek, he works daily as an IT consultant to assist small businesses in overcoming technology challenges and maximizing IT investments. He is also president of Eckel Media Corp., a communications company specializing in public relations and technical authoring projects.