Cisco Cisco Expressway Maintenance Manual
Note:
when using the CLI to add an extra option key, you can use any unused option index. If you chose an existing
option index, that option will be overwritten and the extra functionality provided by that option key will no longer exist.
To see which indexes are currently in use, type
To see which indexes are currently in use, type
xConfiguration option
.
About Security Certificates
For extra security, you may want to have the Expressway communicate with other systems (such as LDAP servers,
neighbor Expressways, or clients such as SIP endpoints and web browsers) using TLS encryption.
neighbor Expressways, or clients such as SIP endpoints and web browsers) using TLS encryption.
For this to work successfully in a connection between a client and server:
■
The server must have a certificate installed that verifies its identity. This certificate must be signed by a
Certificate Authority (CA).
Certificate Authority (CA).
■
The client must trust the CA that signed the certificate used by the server.
The Expressway allows you to install a certificate that can represent the Expressway as either a client or a server in
connections using TLS. The Expressway can also authenticate client connections (typically from a web browser) over
HTTPS. You can also upload certificate revocation lists (CRLs) for the CAs used to verify LDAP server and HTTPS
client certificates.
connections using TLS. The Expressway can also authenticate client connections (typically from a web browser) over
HTTPS. You can also upload certificate revocation lists (CRLs) for the CAs used to verify LDAP server and HTTPS
client certificates.
The Expressway can generate server certificate signing requests (CSRs). This removes the need to use an external
mechanism to generate certificate requests.
mechanism to generate certificate requests.
For secure communications (HTTPS and SIP/TLS) we recommend that you replace the Expressway default certificate
with a certificate generated by a trusted certificate authority.
with a certificate generated by a trusted certificate authority.
Note that in connections:
■
to an endpoint, the Expressway acts as the TLS server
■
to an LDAP server, the Expressway is a client
■
between two Expressway systems, either Expressway may be the client with the other Expressway being the
TLS server
TLS server
■
via HTTPS, the web browser is the client and the Expressway is the server
TLS can be difficult to configure. For example, when using it with an LDAP server we recommend that you confirm
the system is working correctly over TCP before attempting to secure the connection with TLS. We also recommend
using a third party LDAP browser to verify that your LDAP server is correctly configured for TLS.
the system is working correctly over TCP before attempting to secure the connection with TLS. We also recommend
using a third party LDAP browser to verify that your LDAP server is correctly configured for TLS.
Note:
Be careful not to allow your CA certificates or CRLs to expire. This may cause certificates signed by those CAs
to be rejected.
Certificate and CRL files can only be managed via the web interface. They cannot be installed using the CLI.
Managing the Trusted CA Certificate List
The Trusted CA certificate page (Maintenance > Security certificates > Trusted CA certificate) allows you to
manage the list of certificates for the Certificate Authorities (CAs) trusted by this Expressway. When a TLS
connection to Expressway mandates certificate verification, the certificate presented to the Expressway must be
signed by a trusted CA in this list and there must be a full chain of trust (intermediate CAs) to the root CA.
manage the list of certificates for the Certificate Authorities (CAs) trusted by this Expressway. When a TLS
connection to Expressway mandates certificate verification, the certificate presented to the Expressway must be
signed by a trusted CA in this list and there must be a full chain of trust (intermediate CAs) to the root CA.
■
To upload a new file containing one or more CA certificates, Browse to the required PEM file and click
Append CA certificate. This will append any new certificates to the existing list of CA certificates. If you are
replacing existing certificates for a particular issuer and subject, you have to manually delete the previous
certificates.
Append CA certificate. This will append any new certificates to the existing list of CA certificates. If you are
replacing existing certificates for a particular issuer and subject, you have to manually delete the previous
certificates.
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Cisco Expressway Administrator Guide
Maintenance