Will running Tor help defend against a ddos attack on my router? Will Tor help hide my IP address and keep me online during a ddos attack?
You asked a few separate questions. I'll do my best to answer each of them here.
Does Tor protect your router and IP Address provided by my ISP from a DDoS?
The router itself will still be reachable from the IP Address provided by your ISP.
Does Tor hide my IP Address?
If you route all of your traffic over the Tor Network, your adversary will have a hard time associating that IP Address with you and will likely send their attacks to the Tor Exits instead. After a while of seeing you are still posting as normal or doing whatever caused them to attack you in the first place they'll give up and target someone else.
Does Tor make you invincible against people actively targeting you individually with and wish to disrupt your activities?
Social engineering attacks at various levels still exist and few mitigations exist for them, if your adversary knows enough about you personally they may be able to target you through social engineering attacks directed at your ISP, Power Company, Building Security Provider, and other vectors to disrupt your activities that way. Tor is not designed to protect against these types of attacks and its protections rely on you staying anonymous in the first place.
It's higly depends where the attack is pointed to:
- If it's pointed at your IP address, then router will keep it, even in a dynamic IP case, so only changing an address(via switching to another ISP or changing it with your current one) will save you
- If it's pointed at your online ctivities, i.e. they are tracing your IP by checking what address you have used to login into Skype, for example, - then yes, Tor will help you, because they will see that they're hitting a thin air : Tor will change circuits from time to time, so the exits too, and they will not know your real ip like in case #1