By setting cache_crls = yes in /etc/strongswan.conf, a copy of both the base CRL and the latest delta CRL fetched via http from the web server winnetou is saved locally in the directory /etc/swanctl/x509crl on both the roadwarrior carol and the gateway moon when the IPsec connection is set up. The subjectKeyIdentifier of the issuing CA plus the suffixes .crl and _delta.crl are used as unique filename for the cached base CRL and delta CRL, respectively.