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Connection Issues

This page describes common RabbitMQ connection problems and possible solutions.

Cannot Connect To RabbitMQ

Typical exception:

BrokerUnreachableException

Possible causes:

  • RabbitMQ server is not running;
  • incorrect host name;
  • incorrect port;
  • firewall restrictions;
  • DNS resolution failures.

Verify Host Configuration

Verify the configured connection settings.

Example:

var factory = new ConnectionFactory
{
    HostName = "localhost",
    Port = 5672,
    UserName = "guest",
    Password = "guest"
};

Check:

  • host name;
  • port;
  • username;
  • password;
  • virtual host.

Verify RabbitMQ Is Running

Verify RabbitMQ is reachable.

PowerShell:

Test-NetConnection localhost -Port 5672

Expected result:

TcpTestSucceeded : True

Authentication Failures

Typical exception:

ACCESS_REFUSED

Possible causes:

  • invalid username;
  • invalid password;
  • insufficient permissions;
  • invalid virtual host access.

TLS Configuration Issues

If TLS is enabled, verify:

  • certificates are valid;
  • certificates are trusted;
  • TLS settings match the server configuration.

Typical symptoms:

AuthenticationException
SslException

Intermittent Disconnections

Possible causes:

  • network instability;
  • broker restart;
  • load balancer timeout;
  • heartbeat timeout.

Verify:

  • RabbitMQ logs;
  • network logs;
  • channel events.

Consider enabling:

EnableChannelEvents = true;

and subscribing to:

OnChannelEventFired

to observe connection and channel-level events.

Diagnostic Checklist

Before investigating application code:

  • verify RabbitMQ is running;
  • verify network connectivity;
  • verify credentials;
  • verify virtual host permissions;
  • verify TLS configuration;
  • inspect RabbitMQ logs.