# Why do I get a 604010 error when logging in?

The <span class="caps">UCLA</span> Login system assumes that your IP address doesn’t change during your session, but some departments on campus (Med Center for one) run Network Address Translation (<span class="caps">NAT</span>) on their internal networks and this changes the IP address. The solution for the user is to use the <span class="caps">BOL</span> <span class="caps">VPN</span> first.

More official information can be found here.

- [https://i4w.ais.ucla.edu/ils/604010.html](https://i4w.ais.ucla.edu/ils/604010.html)
- [https://spaces.ais.ucla.edu/display/iamucla/DeveloperGuideToHandling604010Errors](https://spaces.ais.ucla.edu/display/iamucla/DeveloperGuideToHandling604010Errors)