Cisco Cisco TelePresence Video Communication Server Expressway Maintenance Manual
Figure 12 Entering subject alternative names for Unified CM registration domains, XMPP federation
domains, and chat node aliases, on the VCS Expressway's CSR generator
domains, and chat node aliases, on the VCS Expressway's CSR generator
Managing Certificate Revocation Lists (CRLs)
Certificate revocation list (CRL) files are used by the VCS to validate certificates presented by client browsers and
external systems that communicate with the VCS over TLS/HTTPS. A CRL identifies those certificates that have been
revoked and can no longer be used to communicate with the VCS.
external systems that communicate with the VCS over TLS/HTTPS. A CRL identifies those certificates that have been
revoked and can no longer be used to communicate with the VCS.
We recommend that you upload CRL data for the CAs that sign TLS/HTTPS client and server certificates. When
enabled, CRL checking is applied for every CA in the chain of trust.
enabled, CRL checking is applied for every CA in the chain of trust.
Certificate Revocation Sources
The VCS can obtain certificate revocation information from multiple sources:
■
automatic downloads of CRL data from CRL distribution points
■
through OCSP (Online Certificate Status Protocol) responder URIs in the certificate to be checked (SIP TLS
only)
only)
■
manual upload of CRL data
■
CRL data embedded within the VCS's Trusted CA certificate file
The following limitations and usage guidelines apply:
■
when establishing SIP TLS connections, the CRL data sources are subject to the Certificate revocation
checking settings on the SIP configuration page
checking settings on the SIP configuration page
■
automatically downloaded CRL files override any manually loaded CRL files (except for when verifying
SIP TLS connections, when both manually uploaded or automatically downloaded CRL data may be used)
SIP TLS connections, when both manually uploaded or automatically downloaded CRL data may be used)
■
when validating certificates presented by external policy servers, the VCS uses manually loaded CRLs only
■
when validating TLS connections with an LDAP server for remote login account authentication, the VCS uses
CRL data within the Trusted CA certificate only
CRL data within the Trusted CA certificate only
Automatic CRL Updates
We recommend that you configure the VCS to perform automatic CRL updates. This ensures that the latest CRLs are
available for certificate validation.
available for certificate validation.
To configure the VCS to use automatic CRL updates:
1.
Go to Maintenance > Security certificates > CRL management.
2.
Set Automatic CRL updates to Enabled.
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Cisco TelePresence Video Communication Server Administrator Guide