NOTE: We highly recommend contracting with a computer consulting firm, information technology professional or Authorized POSitive Software Dealer as our Standard Support does not include network setup, configuration and troubleshooting. Whereas Advanced Support offers "best effort" troubleshooting support for POS hardware problems, networking errors, or other issues that affect the operation of your POSitive product. We can also handle the periodic installation of updates for POSitive products. Alternatively, you can pay à la carte for the POSitive Support department to provide this "best effort" service. Contact POSitive Sales for details and pricing. The reason we recommend this is because we have found that some aspects of setup and configuration of POSitive software, including SQL Server manipulation and network setup, sharing and security, and other troubleshooting steps are not intended for novice or intermediate computer users.
When the IP addresses don't match when pinging the server and the remote machine, then it really becomes a DNS issue at that point which might need to be handled by a certified network technician. However, after a quick web search, I found some information that should point you in the correct direction. Below is a modified excerpt of a conversation that had taken place on uperuser.com:
This is a DNS issue. The name of your old machine has been cached by the other machines on the network. In other words, previously the other machines went to your DNS server and asked what the IP address was of the machine matching that name. The server responded with what was the correct IP at the time, which the PC stored for future reference. This local cached copy is usually discarded after a certain period of time. You can force the purge of the cached information by doing ipconfig /flushdns on the machine you are pinging from using cmd.
If that doesn't work, then the DNS record probably hasn't been updated on the DNS server. You can do ipconfig /registerdns from your new machine to try and force the update. Wait 15 minutes, go to the old machines that have the incorrect IP logged, flush the DNS records again and try to ping again.
If this doesn't work check the A record for (machinename) on your DNS server. It's possible that it's the old IP rather than the new IP. If it's not, the it's likely that the dynamic DNS updates aren't working properly from your DHCP server.
More at: http://superuser.com/questions/538266/wrong-ip-address-when-pinged-from-another-machine
