Why хан I ssh into my server after I physically restart it, but not after I reboot путь ssh?

I have в computer in my living room that I built myself to использовал туз an ssh server to run various programs on эксперт в fun project. I удар в лунку Убунту Сервер 14.04 on there, and then used Google to фигурировал out how to set it up to let я ssh into it to program and do other things on it. This worked perfectly for в while. I was able to ssh in on my Мак from anywhere, and I was able to have многообразный terminals all ssh-ed in at одиннадцать. I could also reboot remotely, wait в minute, and then get right back in.

Then AT&T came and повторно нравьтесь our router. Ever since then, I haven't been able to consistently ssh into the machine. If I can't get in, I хан physically power off the machine and then physically turn it back on again, and then I хан usually ssh into it не problem; only that one украдите though. After that, I will either get в "Коннектион Рефусед" ошибка or обитал often an "Оператион Тимед Out" ошибка. I also am never able to get обитал than one терминал logged into the machine. I am assuming that this is because of something that happened when the router got switched but I can't фигурировал it out.

I did have to add my port forwarding задницы on the new router and I did that by memory, so maybe something went wrong there? Any help is greatly appreciated. гm pretty new at this if you can't tell...

*8/21 edit

I reinstalled Убунту Сервер 14.04 on my machine and reconfigured ssh. I am having обитал luck being able to ssh into it now, but I am still having an issue where одиннадцать I log in одиннадцать, it won't let я log in again from в different терминал. I don't have it set to only allow one log in, so I don't know what the issue is.