Dual-Link Redundancy for a Reliable Network

Sudden loss of connectivity can greatly affect work efficiency. Why not try a dual-link redundant scheme? By deploying dual network links and a smart switching mechanism, network reliability can be greatly increased, and the risk of business interruption reduced.Drawing on real-world experience, we will explain the steps for configuring the system and offer tips on avoiding pitfalls to help you get your network back up and running quickly.

Why does your equipment always suddenly go offline?

Last year our team suffered a loss because of this. The monitoring system would go offline every few days, and we spent hours investigating before we discovered that a mouse had bitten through a network cable.Later, a dual-path solution was implemented, so that in the event of a problem with the main line, the backup line could automatically take over within 0.3 seconds.In other words, a single connection is like walking a tightrope, while dual connections are like a safety net.

Four steps to dual-band configuration.

Checklist for hardware preparations.

Don't rush to start. First you'll need two things: a router that supports link aggregation (a business class model is recommended) and two broadband connections from different ISPs.We found that the combination of Chunghwa and Taiwan Mobile is more reliable than two lines from the same provider, as it avoids the risk of regional network outages.

Main line setting techniques.

The main line should be connected by wire, and the one with the highest bandwidth should be the one used most.The key point: Be sure to turn off your router's "auto power saving" mode. This feature seems to be designed to make our lives easier, but it actually causes frequent reconnections. We'd rather use a little more power to ensure stability.

How to build a backup link.

The best option is to have a wireless network as a backup. A 4G router can be had for as little as NT $ 100.Remember to change the data package for your SIM card to unlimited. We got burned before, when we activated the backup link and the data usage went crazy. The end result was that the data speed was restricted to the point where it was worse than having no connection at all.

Switching tests can't be skipped.

When the main line is cut, the backup line must take over within one second.If the switch time is over two seconds, check the router's fault detection interval setting.

Real-life case studies.

Last week I helped a friend with his factory's network. It turned out that the two lines of his dual-line system were connected to the same switch. So when the power went out, both lines went down.Now the main and backup lines are run on different floors, with the main line on the east wall and the backup line on the west wall. That's true physical separation.Don't forget to do a monthly drill, and upgrade equipment and software when necessary.

Common questions answered.

Many people ask, "Is it really necessary to have home surveillance?For the average user, the best way to go is to just protect the most important equipment, like the NAS and the security system. That's much more cost effective than trying to protect the whole house.