Forcing an IP Address

In the “real” world you simply add an entry to /etc/hosts like myhost

The Mac OS X world is different. For version 10.5 and later you do the following

# Create the mapping
sudo dscl localhost -create /Local/Default/Hosts/x.y.z IPAddress
# flush the cache
sudo dscacheutil -flushcache

# Show the mappings
sudo dscl localhost -readall /Local/Default/Hosts

# Delete a mapping
sudo dscl localhost -delete /Local/Default/Hosts/x.y.z
sudo dscacheutil -flushcache

System Software Notes

Reset printing system in Mac OS X 10.5 – 10.5: How to reset the printing system

But these features are still here, just in new spots. To reset the printing system in Leopard, open the Print & Fax pane, then control-click in the Printers sidebar. There it is: Reset printing system. And the advanced method is available in a toolbar button, as detailed in this hint.