There's more...

If you want to take it one step further, have a look at using tcpdump on your remote side to check out traffic traversing your network:

[vagrant@centos2 ~]$ sudo tcpdump port 8888 -ilo -n

You should see traffic come through:

<SNIP>
15:18:48.991652 IP 127.0.0.1.54454 > 127.0.0.1.ddi-tcp-1: Flags [F.], seq 79, ack 618, win 700, options [nop,nop,TS val 16534669 ecr 16534658], length 0
15:18:48.991677 IP 127.0.0.1.ddi-tcp-1 > 127.0.0.1.54454: Flags [.], ack 80, win 683, options [nop,nop,TS val 16534669 ecr 16534669], length 0
<SNIP>