Common Networking Ports



Along the lines of “knowing your network” with the network security guide. Here are some of the most commonly used network ports. There are 65535 ports that can listen for a connection, so this is not a thorough listing. (These are tcp unless noted otherwise.)


FTP 21 (file transfer protocol, usually ftp servers listen here – usually unencrypted)
SSH 22 (secure shell server, encrypted authentication and data sessions.)
TELNET 23 (unencrypted remote shell access)
SMTP 25 (mail “sending” server… it’s basically listening for incoming mail messages.)
HTTP 80 (web servers)
POP3 110 (Post office protocol – mail servers waiting for someone to retrieve messages.)
NNTP 119 (news server (network news transfer protocol) – this is a newsgroup server)
netbios-ns 137 (netbios nameserver (*Windows networking))
netbios-dgm 138 (netbios datagram (*Windows networking))
netbios-ssn 139 (netbios session (*Windows networking))
imap 143 (imap – a different mail retrieval server)
irc 195 (internet relay chat server)
ldap 389 (ldap directory server)
https 443 (secure http)
microsoft-ds 445
ipp 631 (internet printing protocol)

The above is NOT a complete list. I’ve probably left out many you might consider normal and common. If you have found other ports online it might be useful to compare what you’ve found with the /etc/services file in any available linux distro (that’s usually a pretty thorough list of what the ports are commonly used for.) However, it’s worth noting that a service can be run on a port other than what’s listed above. For instance, an alternate port that webservers frequently use is 8080, but there’s nothing to prevent a webserver from running on port 81, or 3 or 578 (as long as another service isn’t already running there.)

Also, malicious services could run on ports that might not raise suspicion, so it’s worth knowing what open ports are normal for your system and systems on your network.

Related Posts

Blog Traffic Exchange Related Posts
  • Ultravnc for remote computer support A little while back I talked some about TightVNC which for a long time has been my favorite implementation of a remote framebuffer, or remote desktop viewing protocol known as VNC (Virtual Network Computing.) The original VNC (now realvnc) came out of AT&T research labs in the UK and has......
  • How to use wireless networking on a laptop This is one that I run into from time to time. Most laptops the last year or two (actually maybe a bit longer), have built in wireless networking. This is great and makes for easy access to wireless access points just about anywhere. In fact, most current operating systems (Windows......
  • Network Security guide for the home or small business network - Part 2 - A Software Firewall Do I really need a hardware firewall? I'm running XP Service Pack 2 with the built in firewall? (or norton, or zonealarm?) Well, personal firewalls (the name that software firewalls go by) are good for a great many things that hardware firewalls AREN'T. They do have their limitations though and......
Blog Traffic Exchange Related Websites
  • Why Would You Like To Join An Affiliate Internet Marketing Network? Affiliate internet marketing is the latest trend internet. With so many products to offer and services available, sometimes featuring it upon one internet site isn’t enough. Thus, publishers or stores need affiliate marketers, some sites which are going to display ads for your particular cost. On other hand, this can......
  • Cost Per Action – All About Functions Of CPA Network Individuals who have formerly been aware of CPA marketing, right now may have created a clear image of what it is, and how far it can take an online marketing business to. In fact, it also depends on the kind of business that an individual runs on the Net. While......
  • Network Marketing - Fixing Problems From The Ground Up A good majority of people don't really understand network marketing it is like they love the comp plan but they never fully understand what it takes to make  massive success happen in their lives.  I have seen it happen so many times its scary.  A person joins a business all......
PDF24    Send article as PDF   

Similar Posts


See what happened this day in history from either BBC Wikipedia
Search:
Keywords:
Amazon Logo

Comments are closed.


Switch to our mobile site