Cisco Cisco Expressway
Expressway-E has a Fully Qualified Domain Name of expe.example.com
Task 4: Replacing the Default Server Certificate
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).
Authority (CA).
■
The client must trust the CA that signed the certificate used by the server.
The Expressway allows you to install appropriate files so that it can act 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.
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 and obtain certificate requests.
mechanism to generate and obtain 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
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 that
your system is working correctly before you attempt to secure the connection with TLS. You are also recommended to
use a third party LDAP browser to verify that your LDAP server is correctly configured to use TLS.
your system is working correctly before you attempt to secure the connection with TLS. You are also recommended to
use a third party LDAP browser to verify that your LDAP server is correctly configured to use TLS.
Note:
be careful not to allow your CA certificates or CRLs to expire as this may cause certificates signed by those CAs to
be rejected.
To load the trusted CA list, go to Maintenance > Security certificates > Trusted CA certificate.
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Cisco Expressway-E and Expressway-C - Basic Configuration Deployment Guide