A computer implemented method, system, and computer program product for authenticating a remote host to a firewall. The illustrative embodiments allow a requesting host separated from a target host by a firewall to determine, based on exception handling code, that an original request sent to the target host has been intercepted and blocked by the firewall. The illustrative embodiments also allow the requesting host to automatically provide credentials that authenticate the requesting host to the firewall. The illustrative embodiments are particularly applicable in situations when requests are invoked without any user interaction, such as when a timer expires. In such a case, there is no user to provide the needed credentials to authenticate the requesting host. The illustrative embodiments enable a requesting host to access a target host without requiring user intervention.