apache/cassandra · critical · ConfigurationException

If rpc_address is set to a wildcard address (

Error message

If rpc_address is set to a wildcard address (

What it means

When broadcast_rpc_address is not set and rpc_address is the wildcard 0.0.0.0, Cassandra cannot compute a client-facing RPC address, so applyAddressConfig throws this ConfigurationException at startup. A wildcard rpc_address is only valid when an explicit non-wildcard broadcast_rpc_address advertises the node to clients.

Solutions

1. Add a broadcast_rpc_address set to this node's routable IP/hostname
2. Or set rpc_address to the specific interface IP instead of 0.0.0.0
3. Keep rpc_address: 0.0.0.0 only when every node also has an explicit non-wildcard broadcast_rpc_address

Example fix

// cassandra.yaml before
rpc_address: 0.0.0.0
// after
rpc_address: 0.0.0.0
broadcast_rpc_address: 10.0.1.5

String rpc = config.rpc_address;
if ((rpc == null || "0.0.0.0".equals(rpc) || "::".equals(rpc)) && config.broadcast_rpc_address == null) {
    throw new IllegalStateException("rpc_address is wildcard; broadcast_rpc_address must be set");
}

try { DatabaseDescriptor.daemonInitialization(); } catch (ConfigurationException e) { /* correct cassandra.yaml */ }

When it happens

Trigger: cassandra.yaml contains rpc_address: 0.0.0.0 (the default example) with no broadcast_rpc_address defined; DatabaseDescriptor.loadConfig() runs during startup.

Common situations: Fresh installs where operators set rpc_address to 0.0.0.0 to listen on all interfaces but forget the companion broadcast_rpc_address; config generators templating bind addresses only.

Understand the failure class

Background: Conflicting config options: "cannot be used together" — configuration validation errors across open-source libraries — this error's family across 162 libraries.

Related errors

• broadcast_address cannot be a wildcard address (
• broadcast_rpc_address cannot be a wildcard address (
• listen_address cannot be a wildcard address (
• A maximum number of tokens per node is supported
• accord.cache_size option was set incorrectly to

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/e8b25b0f5f775695. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/config/DatabaseDescriptor.java:1587

        /* RPC address to broadcast */
        if (config.broadcast_rpc_address != null)
        {
            try
            {
                broadcastRpcAddress = InetAddress.getByName(config.broadcast_rpc_address);
            }
            catch (UnknownHostException e)
            {
                throw new ConfigurationException("Unknown broadcast_rpc_address '" + config.broadcast_rpc_address + '\'', false);
            }

            if (broadcastRpcAddress.isAnyLocalAddress())
                throw new ConfigurationException("broadcast_rpc_address cannot be a wildcard address (" + config.broadcast_rpc_address + ")!", false);
        }
        else
        {
            if (rpcAddress.isAnyLocalAddress())
                throw new ConfigurationException("If rpc_address is set to a wildcard address (" + config.rpc_address + "), then " +
                                                 "you must set broadcast_rpc_address to a value other than " + config.rpc_address, false);
        }
    }

    public static void applyEncryptionContext()
    {
        // always attempt to load the cipher factory, as we could be in the situation where the user has disabled encryption,
        // but has existing commitlogs and sstables on disk that are still encrypted (and still need to be read)
        encryptionContext = new EncryptionContext(conf.transparent_data_encryption_options);
    }

    public static void applySslContext()
    {
        if (TEST_JVM_DTEST_DISABLE_SSL.getBoolean())
            return;

        try
        {

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