Common IT applications

Now with that list from the ports – you should be wondering – what is FTP? what is TFTP? What is POP3?

Here’s the run down –

For WINDOWS

• NetBIOS is a Microsoft protocol for computer to advertise themselves on the network
• SMTP is protocol for sending email
• DNS is the system to translate names (like www.itcareergeek.com) to IP addresses
• DHCP is how your computer gets an IP address on the network
• HTTP and HTTPS – web traffic
• POP3 is an [unsecure] way to retrieve email from an email server
• NTP is how servers and your computer keeps the same time on the network
• IMAP4 is used to sync your email client to the email on the server
• LDAP/LDAPS are used to lookup accounts or groups on a directory server

For Unix/Linux and Network:

• SSH is an encrypted [secure] protocol for text session and file transfer to and from systems
• Telnet is an unencrypted protocol for a text session to a device or system
• SNMP is a protocol for looking at the management of devices
• BGP is a routing protocol
• FTP and FTPs are used for file transfers to/from devices and servers – SSH is preferred now
• TFTP is use for some devices to pull updates for the device

So, now that you see this, you can focus on those ports, but it’s a good idea to know them all.

For example, many enterprise wireless systems, switches and routers only use TFTP for pulling updates – it’s easy to implement and usually done locally, so IT guys have to go setup a TFTP server and use an SSH session to update the firmware on the device by giving it the TFTP server address.

For Unix or Linux admins – PuTTY is a freeware SSH and Telnet client. It is used to login in remotely to servers or systems.