As I am working with Nexus 7000, Nexus 5000 and 2000 Series Switches, I discovered by default Telnet Server is disabled in a NX-OS devices such as Nexus 7000, Nexus 5000 and 2000 Series Switches.
We all know Telnet protocol enables TCP/IP connections to a host. Telnet allows a user at one site to establish a TCP connection to a login server at another site and then passes the keystrokes from one device to the other. Telnet can accept either an IP address or a domain name as the remote device address.
I will show you how to enable the Telnet Server in NX-OS devices
VDC-Admin(config)# feature telnet
VDC-Admin(config)# show telnet server
telnet service enabled