Ubuntu doesn't have a firewall enabled by default. Did you? It would certainly explain the issue you are seeing.

On the server, run sudo netstat -plunt | grep 4848 If it is running on port 4848, you should see:

tcp6       0      0 :::4848                 :::*                    LISTEN      3962/java       

If you don't then you know that GlassFish is not running properly, and the problem isn't firewalling. If it is listed, run iptables -L to see your file wall settings and check that you are not blocking port 4848.

Greetings,

I`m having the same problem...
Checked ports:

Starting Nmap 7.01 ( https://nmap.org ) at 2018-07-17 00:51 UTC
Initiating Parallel DNS resolution of 1 host. at 00:51
Completed Parallel DNS resolution of 1 host. at 00:51, 0.18s elapsed
Initiating SYN Stealth Scan at 00:51
Scanning IP [1000 ports]
Discovered open port 22/tcp on IP
Discovered open port 3306/tcp on IP
Discovered open port 80/tcp on IP
Discovered open port 8080/tcp on IP
Discovered open port 4848/tcp on IP
Discovered open port 7676/tcp on IP
Discovered open port 8181/tcp on IP
Completed SYN Stealth Scan at 00:51, 1.57s elapsed (1000 total ports)
Nmap scan report for IP
Host is up (0.000015s latency).
Not shown: 993 closed ports
PORT STATE SERVICE
22/tcp open ssh
80/tcp open http
3306/tcp open mysql
4848/tcp open appserv-http
7676/tcp open imqbrokerd
8080/tcp open http-proxy
8181/tcp open unknown

Already installed JDK and the Glassfish, didn`t touch on iptables and when I try on browser ip:8080 or ip:4848 I get this message: Is not possible to access the website. ip took too much time to answer. ERRCONNECTIONTIMED_OUT.