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SymmetricareRoutes

A sender's echo fails

Symptom: the modality’s Echo or Verify to the router fails or times out.

  1. Is the node listening? On the Nodes tab the node must be Running, and list the port among its listening ports. A drained node, or one short of disk (below Minimum free disk), does not listen. A node problem such as Cannot listen on port 104 means another program has the port: choose another port in Settings, or stop that program.
  2. Does the network reach it? From a machine on the modality’s network: Test-NetConnection <router> -Port <port> (Windows) or nc -vz <router> <port>. Check firewalls between the modality and the node (and the load balancer, if there is one, with its health check).
  3. Is it the right address and port? The router’s DNS name must point at the node or the load balancer, and the modality must use the listen port from Settings (11112 by default; 104 only if you set it).
  4. Does the router answer this sender? By default the router answers C-ECHO from anyone. With Answer C-ECHO only from senders matching a route on, a sender no route accepts is rejected: see A sender’s association is rejected.
  5. TLS: a modality configured for TLS must use one of the TLS ports, and trust the node’s certificate; with Senders must present a listed client certificate on, the modality must present one the node trusts.

On Linux, a node can only open ports below 1024 (such as 104) when it has the capability: see Linux.