See, value of proxyport is 3128 in dansguardian configuartion file.
is the port DansGuardian connects to proxy on.
The default port for squid proxy server is 3128. If you would install squid, you would find it is running on 3128
# netstat -lnp | grep :3128
You haven't installed it that's why there is no process on 3128.
The squid's default port is mentioned in dansguardian config file, that's why I think it needs a proxy server to block sites.