Solution:

STEP 1

First Make sure that you can ping the IP address

ping IP

STEP 2

Telnet IP on Port 445

Has there be any IP changes lately? Please make sure that the firewall is properly set.

STEP 3

Check DNS issue

STEP 4

Check firewall (include local firewall or network firewall)

STEP 5

Check your Log files - /var/log/syslog or /var/log/messages