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.
Popularity: 2% [?]
Related Posts - Zeroshell Livecd - providing main network services http://www.zeroshell.net/eng/ is an interesting bundle of linux designed to be an out of the box network service swiss army knife of sorts. Here are the network services that it provides.... Kerberos 5 authentication, LDAP, NIS, Radius authentication, x509 certificate authority, unix and windows compatible active directory services, router, implements bridging......
- UDP problem... I found a peculiar problem while I was setting up an openvpn link the other day. The goal was a simple shared key setup and I started with the sample configuration and modified it a bit to fit the circumstances, I allowed the correct UDP port through the firewall (I......
- Network Security guide for the home or small business network - Part 18 - What about Dialup Users? So, most everything so far has been targetted to high speed internet users or business networks. That means if I use dialup I'm safe. Wrong. For starters, in many ways dialup internet is LESS of a risk than high speed broadband for two main reasons. First, high speed/broadband connections are......
Related Websites - Social Networking For Business Marketing can be very expensive specially for those who run a small business website or own an e-commerce website. In order to make a sale it becomes very important that you market your product or service. Social networks provide a viable internet marketing alternative. Social networking websites tends to attract......
- Essential Steps For Getting Approved By Any Affiliate Network Getting accepted in an affiliate network is a hurdle that many new affiliate marketers face. While getting approved by an affiliate network can be challenging at first, it's much simpler when you understand exactly what they're looking for. The following tips will help you get your applications to these networks......
- 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......
Similar Posts
- Network Security guide for the home or small business network – Part 9 – Know your network
- Network Security guide for the home or small business network – Part 1 – A Hardware firewall
- Network Security guide for the home or small business network – Part 2 – A Software Firewall
- Network Security guide for the home or small business network – Part 4 – Know your software
- Esbot and Zotob updates….