Operation Manual – SSHH3C S3100 Series Ethernet Switches Chapter 1 SSH Configuration1-1Chapter 1 SSH ConfigurationWhen configuring SSH, go to these sections for information you are interested:z SSH Overviewz SSH Server and Client Configuration Task Listz Displaying and Maintaining SSH Configurationz Comparison of SSH Commands with the Same Functionsz SSH Configuration Examples1.1 SSH Overview1.1.1 Introduction to SSHSecure Shell (SSH) is a protocol that provides secure remote login and other securityservices in insecure network environments. In an SSH connection, data are encryptedbefore being sent out and decrypted after they reach the destination. This preventsattacks such as plain text password interception. Besides, SSH also provides powerfuluser authentication functions that prevent attacks such as DNS and IP spoofing.SSH adopts the client-server model. The device can be configured as an SSH client oran SSH server. In the former case, the device establishes a remote SSH connection toan SSH server. In the latter case, the device provides connections to multiple clients.Furthermore, SSH can also provide data compression to increase transmission speed,take the place of Telnet or provide a secure “channel” for FTP.Caution:z Currently, when functioning as an SSH server, an S3100-EI switch supports SSH2and SSH1, while an S3100-SI switch supports only SSH2.z When functioning as an SSH client, an S3100 switch supports only SSH2.z Unless otherwise noted, SSH refers to SSH2 throughout this document.1.1.2 Algorithm and KeyAlgorithm is a set of transformation rules for encryption and decryption. Informationwithout being encrypted is known as plain text, while information that is encrypted isknown as cipher text. Encryption and decryption are performed using a string of
