Always change the default username and password to the routers GUI and ALWAYs enable wireless encryption and all wifi frequencies.
This is needed to prevent "drive-by" connections by every device that comes within range.
Someone can visit and have a phone or tablet in their possession and it WILL latch on your open network.
Also disable Guest Accounts, Remote Access and WPS and all router related "cloud" services.
Also, be aware that there is a Linux kernel vulnerability:
National Cyber Awareness System:
US-CERT is aware of a Linux kernel vulnerability known as Dirty COW (CVE-2016-5195). Exploitation of this vulnerability may allow an attacker to take control of an affected system.
US-CERT recommends that users and administrators review the Red Hat CVE Database, the Canoical Ubuntu CVE Tracker, and CERT Vulnerability Note VU#243144 for additional details, and refer to their Linux or Unix-based OS vendors for appropriate patches.
Do you have a satellite TV receiver connected to your router, or any other device that controls anything in your home? It seems that a lot of different devices were used in the DDOS attack on DYN.
It's entirely possible that, if its connected to your router, your Dish TV receiver was used as a part of the DYN DDOS attack. Again, possible, but that doesn't mean it was for sure. They were one of the things that was used quite a bit in the attack. Unfortunately, without having some type of firmware that allows you to view what data each device uses, you may never know if it was, in fact, used.
They did it through the net, so the fact that your router isn't within range of anybody being able to hack into it wouldn't matter.
I would take the advice and at least change your router GUI password, even if you can't change the sign in name (some of them are locked in with the name "admin" and can't be changed). I don't know if that would stop the type of attack that happened, or even if your device was involved, but it's still a good idea to have the router GUI password protected, anyway.