Remove --ip-version CLI flag, always use dual-stack

README.md

@@ -907,7 +907,6 @@ You can also specify bootstrap peers explicitly:
 ./target/release/ant-node \
     --root-dir ~/.ant-node \
     --port 12000 \
-    --ip-version dual \
     --upgrade-channel stable \
     --migrate-ant-data auto \
     --log-level info
@@ -929,9 +928,9 @@ Options:
         Listening port (0 for automatic selection)
         [default: 0]
 
-    --ip-version <VERSION>
-        IP version to use: ipv4, ipv6, or dual
-        [default: dual]
+    --ipv4-only
+        Force IPv4-only mode (disable dual-stack).
+        Use on hosts without working IPv6.
 
     --bootstrap <ADDR>
         Bootstrap peer socket addresses (can be specified multiple times)
@@ -1003,7 +1002,6 @@ peers = [
 ```bash
 export ANT_ROOT_DIR=~/.ant-node
 export ANT_PORT=12000
-export ANT_IP_VERSION=dual
 export ANT_LOG_LEVEL=info
 export ANT_AUTO_UPGRADE=true
 export ANT_UPGRADE_CHANNEL=stable
@@ -1016,7 +1014,6 @@ export ANT_UPGRADE_CHANNEL=stable
 ```toml
 root_dir = "~/.ant-node"
 port = 0  # Auto-select
-ip_version = "dual"
 bootstrap = [
     "10.0.0.1:10000",
     "10.0.0.2:10000",

config/production.toml

@@ -9,9 +9,6 @@ root_dir = "/var/lib/ant"
 # Listening port (10000-10999 for production)
 port = 10000
 
-# IP version: "ipv4", "ipv6", or "dual"
-ip_version = "dual"
-
 # Bootstrap peer addresses (socket addrs)
 bootstrap = []
 

scripts/testnet/spawn-nodes.sh

@@ -58,7 +58,7 @@ Type=simple
 ExecStart=/usr/local/bin/ant-node \\
     --root-dir ${NODE_DIR} \\
     --port ${PORT} \\
-    --ip-version ipv4 \\
+    --ipv4-only \\
     --network-mode testnet \\
     ${BOOTSTRAP_FLAGS} \\
     --metrics-port ${METRICS} \\

scripts/testnet/start-genesis.sh

@@ -23,7 +23,7 @@ Type=simple
 ExecStart=/usr/local/bin/ant-node \
     --root-dir /var/lib/ant/nodes/node-0 \
     --port 12000 \
-    --ip-version ipv4 \
+    --ipv4-only \
     --metrics-port 9100 \
     --log-level info \
     --upgrade-channel stable \
@@ -64,7 +64,7 @@ Type=simple
 ExecStart=/usr/local/bin/ant-node \
     --root-dir /var/lib/ant/nodes/node-50 \
     --port 12000 \
-    --ip-version ipv4 \
+    --ipv4-only \
     -b 142.93.52.129:12000 \
     --metrics-port 9100 \
     --log-level info \

src/bin/ant-node/cli.rs

@@ -1,8 +1,8 @@
 //! Command-line interface definition.
 
 use ant_node::config::{
-    BootstrapCacheConfig, BootstrapPeersConfig, BootstrapSource, EvmNetworkConfig, IpVersion,
-    NetworkMode, NodeConfig, PaymentConfig, UpgradeChannel,
+    BootstrapCacheConfig, BootstrapPeersConfig, BootstrapSource, EvmNetworkConfig, NetworkMode,
+    NodeConfig, PaymentConfig, UpgradeChannel,
 };
 use clap::{Parser, ValueEnum};
 use std::net::SocketAddr;
@@ -21,9 +21,11 @@ pub struct Cli {
     #[arg(long, short, default_value = "0", env = "ANT_PORT")]
     pub port: u16,
 
-    /// IP version to use.
-    #[arg(long, value_enum, default_value = "dual", env = "ANT_IP_VERSION")]
-    pub ip_version: CliIpVersion,
+    /// Force IPv4-only mode (disable dual-stack).
+    /// Use on hosts without working IPv6 to avoid advertising
+    /// unreachable addresses to the DHT.
+    #[arg(long, env = "ANT_IPV4_ONLY")]
+    pub ipv4_only: bool,
 
     /// Bootstrap peer addresses.
     #[arg(long, short, env = "ANT_BOOTSTRAP")]
@@ -112,17 +114,6 @@ pub struct Cli {
     pub bootstrap_cache_capacity: usize,
 }
 
-/// IP version CLI enum.
-#[derive(Debug, Clone, Copy, ValueEnum)]
-pub enum CliIpVersion {
-    /// IPv4 only.
-    Ipv4,
-    /// IPv6 only.
-    Ipv6,
-    /// Dual-stack (both IPv4 and IPv6).
-    Dual,
-}
-
 /// Upgrade channel CLI enum.
 #[derive(Debug, Clone, Copy, ValueEnum)]
 pub enum CliUpgradeChannel {
@@ -215,7 +206,7 @@ impl Cli {
         }
 
         config.port = self.port;
-        config.ip_version = self.ip_version.into();
+        config.ipv4_only = self.ipv4_only;
         config.log_level = self.log_level.into();
         config.network_mode = self.network_mode.into();
 
@@ -266,16 +257,6 @@ impl Cli {
     }
 }
 
-impl From<CliIpVersion> for IpVersion {
-    fn from(v: CliIpVersion) -> Self {
-        match v {
-            CliIpVersion::Ipv4 => Self::Ipv4,
-            CliIpVersion::Ipv6 => Self::Ipv6,
-            CliIpVersion::Dual => Self::Dual,
-        }
-    }
-}
-
 impl From<CliUpgradeChannel> for UpgradeChannel {
     fn from(c: CliUpgradeChannel) -> Self {
         match c {

src/config.rs

@@ -10,19 +10,6 @@ pub const NODE_IDENTITY_FILENAME: &str = "node_identity.key";
 /// Subdirectory under the root dir that contains per-node data directories.
 pub const NODES_SUBDIR: &str = "nodes";
 
-/// IP version configuration.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Default, Serialize, Deserialize)]
-#[serde(rename_all = "lowercase")]
-pub enum IpVersion {
-    /// IPv4 only.
-    Ipv4,
-    /// IPv6 only.
-    Ipv6,
-    /// Dual-stack (both IPv4 and IPv6).
-    #[default]
-    Dual,
-}
-
 /// Upgrade channel for auto-updates.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default, Serialize, Deserialize)]
 #[serde(rename_all = "lowercase")]
@@ -99,9 +86,13 @@ pub struct NodeConfig {
     #[serde(default)]
     pub port: u16,
 
-    /// IP version to use.
+    /// Force IPv4-only mode.
+    ///
+    /// When true, the node binds only on IPv4 instead of dual-stack.
+    /// Use this on hosts without working IPv6 to avoid advertising
+    /// unreachable addresses to the DHT.
     #[serde(default)]
-    pub ip_version: IpVersion,
+    pub ipv4_only: bool,
 
     /// Bootstrap peer addresses.
     #[serde(default)]
@@ -249,7 +240,7 @@ impl Default for NodeConfig {
         Self {
             root_dir: default_root_dir(),
             port: 0,
-            ip_version: IpVersion::default(),
+            ipv4_only: false,
             bootstrap: Vec::new(),
             network_mode: NetworkMode::default(),
             testnet: TestnetConfig::default(),

src/node.rs

@@ -2,7 +2,7 @@
 
 use crate::ant_protocol::{CHUNK_PROTOCOL_ID, MAX_CHUNK_SIZE};
 use crate::config::{
-    default_nodes_dir, default_root_dir, EvmNetworkConfig, IpVersion, NetworkMode, NodeConfig,
+    default_nodes_dir, default_root_dir, EvmNetworkConfig, NetworkMode, NodeConfig,
     NODE_IDENTITY_FILENAME,
 };
 use crate::error::{Error, Result};
@@ -151,12 +151,11 @@ impl NodeBuilder {
 
     /// Build the saorsa-core `NodeConfig` from our config.
     fn build_core_config(config: &NodeConfig) -> Result<CoreNodeConfig> {
-        let ipv6 = matches!(config.ip_version, IpVersion::Ipv6 | IpVersion::Dual);
         let local = matches!(config.network_mode, NetworkMode::Development);
 
         let mut core_config = CoreNodeConfig::builder()
             .port(config.port)
-            .ipv6(ipv6)
+            .ipv6(!config.ipv4_only)
             .local(local)
             .max_message_size(config.max_message_size)
             .build()
@@ -862,6 +861,23 @@ mod tests {
         assert!(core.diversity_config.is_some());
     }
 
+    #[test]
+    fn test_build_core_config_ipv4_only() {
+        let config = NodeConfig {
+            ipv4_only: true,
+            ..Default::default()
+        };
+        let core = NodeBuilder::build_core_config(&config).expect("core config");
+        assert!(!core.ipv6, "ipv4_only should disable IPv6");
+    }
+
+    #[test]
+    fn test_build_core_config_dual_stack_by_default() {
+        let config = NodeConfig::default();
+        let core = NodeBuilder::build_core_config(&config).expect("core config");
+        assert!(core.ipv6, "dual-stack should be the default");
+    }
+
     #[test]
     fn test_build_core_config_sets_development_mode_permissive() {
         let config = NodeConfig {