For many of us, rebooting our router has become a way of life. Maybe you’re in the middle of watching a show on Netflix, participating in a online meeting, or trying to access your smart home devices while on vacation and all of a sudden your connection stops working. What a pain!!! Now you have to climb up to the router shelf, unplug it, wait 30 seconds, plug it back in and wait for your connection to come back. FYI, our Keep Connect product (Amazon link above) will handle this for you by automatically monitoring and performing the reset so you don’t have to!
While there are a number of reasons why this happens, below are the top causes:
Software Errors in your Router/Modem
Your modem / router has to communicate with your Internet Service Provider (ISP) and obtain an IP address for your home or business location. In addition to obtaining one automatically from the ISP, it also has to issue IP addresses to all of your connected devices (one IP per device) and assemble all of these IP addresses into routing tables stored in memory. A number of issues can cause the IP addresses and routing stored in your routers memory to become corrupt and unusable. If the ISP device reboots, it’s possible that it may hand out your IP address to another customer by mistake (not having remembered that it already dynamically assigned that one to you before rebooting). Two devices having the same IP can cause a multitude of issues. Also, devices on your local network may do things in communicating with your router that confuse its routing tables or even corrupt the MAC address tables by issuing gratituous ARPs which is when a device chooses to send out a broadcast to all devices informing its IP address and MAC address combination. Small errors within this system can result in the router (which has to keep track of all this) losing track of the system and no longer being able to perform its job.
Simple solution?! Just reboot it and let it re-establish the system from scratch and rebuild all of its internal representation of the network at hand. Also upon reboot, it will reach out to the ISP and request an IP address to use which should also get it back in-sync with the ISP’s system.
Domain Name Server (DNS) Issues A DNS server is another computer whose job is to turn website addresses (i.e. www.example.com) into IP addresses for your web browser to use to download the content. This process is much like looking up a phone number by a person’s name in a phone book. Typically, your Internet Service Provider (ISP) has their own DNS servers that your router learns about when it requests an IP address from the ISP. Your router then distributes the IP address of the DNS Server to each device connected to your local network allowing each of them to contact the DNS server on their own to lookup IP addresses for their browser’s use. If your ISP changes DNS servers or somehow the system topology changes, your network may become unable to reach the DNS servers and can no longer turn website names into IP addresses that are needed to establish actual connections. The internet connection still exists and is healthy, but your devices are not able to lookup any IP addresses to connect with. This would be like losing your phone book (in the old days) and still having a working telephone. You can still reach someone if you know their number but if you don’t remember their phone number the phone service is useless.
Simple Solution?! Again, just reboot your router/modem and let it re-establish the network topology and DNS servers advertised by your ISP. In some cases, if you regularly experience issues with this, you could also change your DNS servers to permanently point to Google’s free DNS servers (22.214.171.124 and 126.96.36.199) which are extremely reliable and often faster than ISP provided DNS servers.
Sometimes, in attempt to throttle connections, we’ve seen ISP’s begin to block connections. They block portions of the internet, but sometimes not everything. For instance, blocking only the HTTP service which is what web browsers use. Rebooting the router re-establishes the connection defeating the throttling attempt (at least until the next attempt).