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This page is being updated and refined - the information on it is not yet considered to be "official". Thanks for your understanding!

IP Address mismatch and ISIS session termination

If you received the below error, its likely that your login session has been terminated and you are not able to access applications.

We cannot verify the authenticity of the session. User's IP address has changed since the initial Logon. This is a Security Violation and the session has been terminated

How can I resolve this problem

1. Try VPN to UCLA and then access the application. If you need assistance with VPN visit UCLA VPN Page

2. If you are inside the campus you are probably inside a private network or application you are trying to access is hosted inside a private network in campus. Please contact application support team.

Why am I seeing this error

Many campus applications rely on ISIS system to perform authentication. ISIS collects browser IP address during initial login. Applications also collect and pass user's browser IP address to ISIS from time to time, to verify if the session is still active.
If the two IP addresses do not match during session verification ISIS terminates the session. This is a security measure to prevent possible ISIS session hijacking.

Why the two IP addresses may be different

This may happen due to various Network configurations at your ISP, at campus departments, Applications hosted on private networks etc.

For ex:
1. User is outside the campus, coming from ISP (Internet Service Provider like AOL, Comcast). ISP uses dynamic proxy. ISIS sees one IP Address during initial login. Application sees a different IP Address during session verification.
2. User is operating inside a private network in the campus. User trying to access an application which is hosted within the private network. ISIS sees user's public IP address during initial login, where as application sees private IP address during session verification.

For more technical details visit ReinstateIpChecking

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