I have brought a dynDNS service, and tried using Integrated DynDNS provider but I seem to be facing the problem with port forwarding. I want to SSH onto my Ubuntu system from another network using an iPad. I tried verifying with www.portchecktool.com and all common ports seemed to be blocked. So, I changed my SSH port assuming that my ISP blocked those common ports or something. Even that port isn't accessible.
At first I was using the wifi router at home, now I connected my system directly connected to Internet through ethernet cable provided by the ISP. So, I don't know which router my ISP uses, so DynDNS is the only option.
I have a problem doing and verifiying port forwarding.
If I could connect through a local connection, I assumed that firewall in my system isn't causing any problem.
Ok, first of all DynDNS != ISP port blocking or anything of that like.
Your ISP won't block ports on your router unless they use them for remote connection support or whatever other reason.
By default every router has a firewall that blocks all port access from the outside which is good for the normal user, you don't want to create vulnerabilites to people that have no idea what they are doing on the internet.
Now what you have to do is not only portfoward but also allow access on those ports from the outside in the router firewall. These are 2 seperate things.
And in general it is a good idea to not use the default SSH port on the outside, since you can portfoward e.g. external port 53299 -> internalmachineip:22 it is a lot saver to just use a non default port to go past all those automatic crawlers.