So just TCP 8333 is opened not UDP.. Should both of them must be enabled?
If so how can i enable UDP on ubuntu ssh?
What you should be checking is your router, not the firewall on your computer. Since the program opens up the port, you shouldn't need to do any extra configuring on the computer unless you have specifically set up such firewalling rules.
Only TCP is necessary.
The nodes that are connected to blockchain.info is not the definitive list of all nodes. Bitnodes.21.co's list of reachable nodes likewise is also not definitive as their crawler also doesn't necessarily reach all nodes (although it is designed to do that).B
lockchain.info's "relayed by" field is completely irrelevant and useless. They only show the node that is connected to them that first relayed the transaction to them. Even if your node is connected to theirs (and I highly doubt it, they only have a hundred or so nodes connected), you won't necessarily have anything listed for "relayed" if all of the other nodes they are connected to relay the transaction to them before you do.
If Bitcoin Core reports that you have more than any number of incoming connections, then you are accepting incoming connections and are fine. You don't have to be listed on any site like bitnodes in order to be accepting incoming connections.
