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Nortel CS1000 ELAN009 Alarm

Jeremy Boilard

Problem Statement

A Nortel CS1000 (CS1K) reports a Minor ELAN009 alarm. The alarm indicates that an ELAN host IP is disabled because a write to socket failed due to a far-end disconnect, Ethernet issue, or network interface problem.

Impact

The affected ELAN link or host connection may be unavailable or unstable. Management, signaling, or application connectivity that depends on the ELAN path may be degraded until the link is restored.

Alarm

ELAN009: ELAN host IP disabled; write to socket failed due to far-end disconnect, Ethernet problems, or network interface problems. Alarm clear/restore indication may appear as ELAN014: ELAN host IP is enabled.

Troubleshooting Steps

  1. Confirm the active alarm details in the monitoring dashboard, including device type, maintained object, ELAN link number, alarm code, and alarm timestamp.
  2. Check whether a corresponding ELAN014 restore event has already occurred. If ELAN014 shows the ELAN host IP is enabled, verify the ELAN009 alarm has cleared in the dashboard.
  3. If the alarm remains active, verify network reachability between the CS1000 ELAN interface and the far-end host using standard network tests such as ping or traceroute from an appropriate management point.
  4. Check for Ethernet or interface issues on the network path, including link status, switch port errors, duplex/speed mismatch, packet loss, interface flaps, or disabled ports.
  5. Verify that the far-end host or application endpoint is reachable and that the relevant service is running and accepting connections.
  6. Review recent network, firewall, routing, VLAN, or access-control changes that could interrupt socket connectivity between the CS1000 and the far-end host.
  7. If connectivity has recovered but the alarm remains displayed, refresh or resynchronize the alarm view and confirm current alarm state from the CS1000 management interface or monitoring platform.
  8. If the ELAN009 alarm persists after network and far-end checks, escalate to the voice/network operations team for deeper CS1000 ELAN and network-path investigation.

Resolution

The alarm is resolved when ELAN connectivity is restored and the CS1000 reports the ELAN host IP as enabled, typically shown by an ELAN014 event. Confirm that the ELAN009 alarm clears from the monitoring dashboard and that dependent services are operating normally.