SSH INTERVIEW QUESTIONS

Which protocol does SSH use at the transport layer

TCP

What is an equivalent of SSH to remotely connect to a device

Secure -FTP, which is also a secure protocol for remote connection.

A firewall should be configured to allow incoming SSH communication. Which protocol and number should be used

TCP port 22.

Why should SSH be used instead of telnet

SSH is a secure protocol and uses encryption, whereas telnet sends data in clear text and does not use encryption.

Name a tool /utility which you have used where SSH client is available for use

Putty.

What should be copied to a SSH client before authenticating it with the server.

The server public key must be copied. This would be used along with the private key on the client for authentication.

Name two cryptographic algorithms which can be used for generating a private /public key pairs for ssh authentication.

RSA, DSA

What is the difference between SSL and SSH

SSL is an encryption protocol used by application layer protocols like https to encrypt application layer data. SSL is internally used by application layer protocols. SSH is a remote connectivity protocol which is used by clients / users to connect to remote devices.

Does SSH use symmetric or asymmetric encryption

SSH uses two key pairs, private and public, making it asymmetric encryption

In a ssh encryption is the private key shared with the server

No. The private key is not shared. It is private and stored on the client on which SSH is installed.