This week we discussed TCP/IP, more on encapsulation, and ports. The encapsulation process of adding headers through each layer and then unpackaged at the receiving end. Much like in the two pictures below.
We also discussed ports. Below is a list of the most common ports:
The most common ports include:
- 20;21 – FTP
- 22 – SSH
- 23 – Telnet
- 25 – SMTP
- 80 – HTTP
- 110 – POP3
- 143 – IMAP
- 443 – HTTPS
- 1701 – L2TP (UDP) – not compatible with NAT
- 1723 – PPTP (TCP)
- 3389 – MS Remote Desktop/Terminal Services
- 5631 & 5632 – pcAnywhere
To explain ports a good analogy was used. Like that of a House with a physical mailing address, the house has multiple different utilities on different ports like water, gas, electric, cable, phone, internet, and trash. All of these are routed to the house with an address like that of an IP address. This can be thought of as how ports pertain to networks and switches.
Lastly I contributed this week to the Wiki: I edited the Encapsulation and TCP ports. http://ksunetworking.wikispaces.com/02-27-2012+Encapsulation+TCPIP there is a good video and list of common ports and a link to the full list of ports used.
I also contributed a link to Diigo: http://www.networkworld.com/news/2011/122311-naval-researchers-pioneer-tcp-based-spam-254400.html