In order to test sometimes you need to create a fake local DNS. This is so that only your computer can visit a new site before it becomes public.
If your computer is managed by UCSF you may have trouble following these directions as Symantec Endpoint Protection will prevent you from editing your host file. You may need to submit a DNS request for your development environment in this case.
Alter local host file and test local environment
For window users that will be something like:
C:\Windows\System32\drivers\etc\hosts
on Linux and Macs:
/etc/hosts
add the new entry
127.0.0.1 emergency.ucsf.edu
Flushing DNS
Go to a command prompt on a PC or terminal window on Linux/Mac
On Windows
ipconfig /renew
or
ipconfig /flushdns
On linux:
/etc/rc.d/init.d/nscd restart
On mac
dscacheutil -flushcache
Testing DNS update
Very simple just "ping" your new host
ping emergency.ucsf.edu