Linux 远程登录ssh与telnet
telnet服务器和域名系统的端口号
root@am335x-evm:/# grep telnet /etc/services
telnet 23/tcp
rtelnet 107/tcp # Remote Telnet
rtelnet 107/udp
telnets 992/tcp # Telnet over SSL
telnets 992/udp
tfido 60177/tcp # fidonet EMSI over telnet
root@am335x-evm:/# grep domain /etc/services
domain 53/tcp nameserver # name-domain server
domain 53/udp nameserver
ssh服务器端口号
root@am335x-evm:/# grep ssh /etc/services
ssh 22/tcp # SSH Remote Login Protocol
ssh 22/udp
ssh与telnet区别
ssh与telnet较为类似,都是远程登录工具。
ssh分为两部分:服务器端和客户端
服务器端是一个守护进程,用于处理客户端的连接请求,一般为sshd
客户端包括ssh程序以及scp,slogin,sftp等其他应用程序
他们之间最大的不同是ssh对传输加密,安全性高,telnet使用明文传输,较为不安全。
[表格差异源自](https://techdifferences.com/difference-between-telnet-and-ssh.html#Definition)
BASIS FOR COMPARISON | TELNET | SSH |
---|---|---|
Security | Less secured | Highly secured |
Uses port number | 23 | 22 |
Data format | Telnet sends the data in plain text. | Encrypted format is used to send data and also uses a secure channel. |
Authentication | No privileges are provided for users authentication. | Uses Public key encryption for authentication. |
Suitability of network | Private networks are recommended. | Suitable for Public networks. |
Vulnerabilities | Vulnerable to security attacks. | SSH has overcome many security issues of telnet. |
Bandwidth Usage | Low | High |