It means that the standard port assigned to telnet is 23. It is the default port. If you install a telnet server with a default configuration it will listen to port 23. Accordingly if you use a telnet client without specifying a port, it will try to connect to the port 23 of the destination. It also means that no other service should use this port.

2020年9月14日 · Close Port 23 Hi everyone, I have a Dell Powerconnect 6224, we have a security rule to diable all telnet protocols, the issue is I disabled the telnet on that switch put the port 23 still open and it shows up every time when we do a port scan, My Question Is There a Way To Close the Port 23?

2023年10月4日 · Port 23 is a TCP port traditionally assigned to a telnet daemon. Telnet is a simple protocol used a long time ago for a computer to log into a Unix server or mainframe. You would open a telnet ...

2023年12月15日 · Port 7 (both TCP and UDP) is used for the "echo" service. If this service is available on a computer, UDP port 7 could be used instead of ICMP to perform a "ping". However, most modern computers don't have the "echo" service running, so performing "ping" using UDP port 7 instead of ICMP would not work.

2015年1月8日 · Of course, we need it to work on the new switch alone. When we use port 23 on the new switch connected to the fiber directly via the SFP module, port 23 switches to fiber mode and stays down. The same happens when we try port 24. The same happens when we try the old SFP module (which works in the old switch) in either SFP port on the new switch..

IANA maintains the registry for port numbers (be warned, it is currently 138 pages): Service Name and Transport Protocol Port Number Registry. An application layer protocol is free to use any transport layer protocol and port number. By convention, most use specific port numbers in the registry, but that doesn't mean they can't use others, too.

2004年4月30日 · Have done some port scans and it seems I have an open port, (23). Have contacted online techs for Linksy and keep getting conflicting info. One says it should be closed and another says its cofigured open. Anyway I just want all my ports closed and cant figure how to do it on my Linksy filter page. Can someone walk me through it?

2015年3月2日 · Port definition is done in the diaogue establishment process. In the TCP/IP model, Layers 5,6 and 7 of the OSI model are included into one Layer (Layer 4 of the TCP/IP model). So to answer your question, it all depends on the model you are considering. if you are using the OSI model, "Port" is a layer 5 definition, otherwise if you are using ...

2011年2月17日 · tag as U port 1-10. tag as T port 23. set to vlan3. tag as U port 11-20. tag as T port 23. go to vlan port setting. for port 1 - 10 set the PVID to 2. for port 11-20 set the pvid to 3. leave the PVID of port 23 to 1. do the same on the other switch. Voila! you have 2 vlan on each switches and the switches communicates on port 23.

The telnet protocol (RFC 854) uses port 23 by default. On the other hand, the "telnet" program installed on computers can be used to connect to any TCP port on the remote host. "telnet 34.56.78.90 110" will, for example, start a connection to the IMAP server on 34.56.78.90, and you can type commands as per the IMAP protocol and read the server ...