From what you say, I assume you have an ADSL Modem Router with your 'puter networked to it.
192.168.0.0 to 192.168.255.255 are private addresses used on local networks (i.e. not over the internet). See click here
It is quite common for the 'puter to ping the router.
ZA doesn't know anything about your network unless you tell it. I set ZA up to have a Trusted Local Net (added under the Firewall tab) which includes the range of 192.168.xxx.xxx that I use and so access is allowed automatically by ZA.