Checking IP address used in a web service

Hi gurus:

I have a web service that works. The problems appears when the external system change the IP associated to the endpoint of the web service. The SAP PI server retains the old IP address and continues sending requests to it.

I have configured the JVM to not cache the IP addresses. (TTL=0), I think.

How could I monitor the IP address that are used to access to the endpoint of the web service? In the SXI_Monitor transaction I can't see it.

Thanks in advance and regards,

Alejandro Gómez.