Cisco 300-820 - Implementing Cisco Collaboration Cloud and Edge Solutions Certification Exam

The error message "XCP_JABBERD Detail='Unable to connect to host '%IP%', port 7400:(111) Connection refused'" indicates that the Expressway-C is unable to establish a connection with the Expressway-E on port 7400, which is used for the Extensible Communications Platform (XCP) session required for Jabber's Mobile and Remote Access (MRA) functionality. This issue is commonly associated with network or configuration problems on the Expressway-E. According to Cisco documentation, the primary cause of this error is that the Expressway-E is listening for the XCP session on the wrong network interface, which causes the connection to fail or timeout. The Expressway-E listens on TCP port 7400 for the XCP session, and this can be verified using the netstat command from the VCS as root. If the Expressway-E is configured with an incorrect network interface (e.g., due to a single NIC configuration or misconfigured Advanced Networking Option), the XCP session cannot be established, resulting in the "Connection refused" error. Option A (Rich Media Session licenses are not activated on Expressway-E): This is incorrect because Rich Media Session licenses are related to call control for media sessions (e.g., SIP or H.323 calls) and not directly to the XCP session used for Jabber’s MRA functionality. The error specifically points to a connection issue on port 7400, not a licensing problem. Option B (Expressway-E is listening on the wrong IP interface): This is the correct answer. As per Cisco’s troubleshooting guide, the Expressway-E may listen on an incorrect network interface, especially in scenarios where the Advanced Networking Option is enabled or a single NIC is used. This misconfiguration prevents the Expressway-C from connecting to the Expressway-E on port 7400, leading to the connection refusal. Option C (The destination port for Expressway-E is set to 7400 instead of 8443 on the Expressway-C): This is incorrect because port 7400 is the correct port for the XCP session between Expressway-C and  Expressway-E in MRA deployments. Port 8443 is used for HTTPS traffic (e.g., configuration downloads or UDS queries), not for XCP. The error indicates a connection issue on port 7400, not a misconfigured port. Option D (The XCP Service is not activated on Expressway-E): This is unlikely because if the XCP service were not activated, the error might indicate a service failure or unavailability rather than a "Connection refused" error, which specifically points to a network-level issue. Additionally, the XCP service is typically enabled by default for MRA functionality. Exact Extract from Cisco Documentation: "The reason this is a problem is because Expressway-E listens for the XCP session on the wrong network interface, which causes the connection to fail/timeout. Expressway-E listens on TCP port 7400 for the XCP session. You can verify this if you use the netstat command from the VCS as root. If Expressway-E Network Interface Controller (NIC) is incorrectly configured, this can cause the Extensible Communications Platform (XCP) server to not be updated. If Expressway-E meets these criteria, then you will probably encounter this issue: Uses a single NIC. Advanced Networking Option Key is installed." Source: Cisco Document - Resolve Collaboration Edge Most Common Issues, Published 2024-09-03. Additional Notes: To resolve this issue, ensure that the Expressway-E is configured to listen on the correct network interface for the XCP session. This may involve checking the NIC configuration, disabling the Advanced Networking Option if not needed, or verifying firewall rules to ensure that traffic on port 7400 is allowed between Expressway-C and Expressway-E. Additionally, confirm that the DNS and SRV records (_collab-edge) are correctly configured to resolve to the Expressway-E’s proper interface. Reference: Cisco Document: Resolve Collaboration Edge Most Common Issues, Published 2024-09-03. CCNP Collaboration Cloud and Edge Solutions CLCEI 300-820 Official Cert Guide, Cisco Press, Published 2021-11-24, Chapter on Mobile and Remote Access Configuration. Implementing Cisco Collaboration Cloud and Edge Solutions (CLCEI) v1.0 Course, Section on Troubleshooting MRA Issues.