2013-06-10 11:21:45 GMT FATAL: could not connect to the primary server: could not connect to server: No route to host Is the server running on host "192.168.0.4" and accepting TCP/IP connections on port 5432?
Did anything get changed on the standby or master around the time this message started occurring?
On the master, what do the following show?
show port; show listen_addresses;
The master's IP is still 192.168.0.4?
Have you tried connecting to the master using something like: psql -h 192.168.0.4 -p 5432 -U postgres -d postgres