VMwares vSphere Management Assistant does not have much tools available. When you vMA is behind a firewall you might want to check if ports are reachable for troubleshooting purposes. As the vMA does not come with telnet or netcat you can use the built in bash feature:
Bash Manpage
/dev/tcp/host/port If host is a valid hostname or Internet address, and port is an integer port number or service name, bash attempts to open a TCP connection to the corresponding socket. dev/udp/host/port If host is a valid hostname or Internet address, and port is an integer port number or service name, bash attempts to open a UDP connection to the corresponding socket.
Usage
vi-admin@vma.virten.local:~> cat < /dev/tcp/127.0.0.1/22 SSH-2.0-OpenSSH_5.1 ^C
A list of services and port numbers is available at /etc/services