diff --git a/Cargo.lock b/Cargo.lock
index dc97ce0ca..1f41ea021 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1103,7 +1103,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "rocksdb"
 version = "0.4.5"
-source = "git+https://github.com/ethcore/rust-rocksdb#9140e37ce0fdb748097f85653c01b0f7e3736ea9"
+source = "git+https://github.com/ethcore/rust-rocksdb#e0e6c099d8cd156fe446009fce241d57b00cd8f4"
 dependencies = [
  "libc 0.2.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "rocksdb-sys 0.3.0 (git+https://github.com/ethcore/rust-rocksdb)",
@@ -1112,7 +1112,7 @@ dependencies = [
 [[package]]
 name = "rocksdb-sys"
 version = "0.3.0"
-source = "git+https://github.com/ethcore/rust-rocksdb#9140e37ce0fdb748097f85653c01b0f7e3736ea9"
+source = "git+https://github.com/ethcore/rust-rocksdb#e0e6c099d8cd156fe446009fce241d57b00cd8f4"
 dependencies = [
  "gcc 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.12 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/ethcore/src/miner/transaction_queue.rs b/ethcore/src/miner/transaction_queue.rs
index cc8430b42..06aa07880 100644
--- a/ethcore/src/miner/transaction_queue.rs
+++ b/ethcore/src/miner/transaction_queue.rs
@@ -686,14 +686,15 @@ impl TransactionQueue {
 		if let Some(order) = self.future.drop(&address, &nonce) {
 			// Let's insert that transaction to current (if it has higher gas_price)
 			let future_tx = self.by_hash.remove(&order.hash).unwrap();
-			try!(check_too_cheap(Self::replace_transaction(future_tx, state_nonce, &mut self.current, &mut self.by_hash)));
+			// if transaction in `current` (then one we are importing) is replaced it means that it has to low gas_price
+			try!(check_too_cheap(!Self::replace_transaction(future_tx, state_nonce, &mut self.current, &mut self.by_hash)));
 		}
 
 		// Also enforce the limit
 		let removed = self.current.enforce_limit(&mut self.by_hash);
 		// If some transaction were removed because of limit we need to update last_nonces also.
 		self.update_last_nonces(&removed);
-		// Trigger error if we were removed.
+		// Trigger error if the transaction we are importing was removed.
 		try!(check_if_removed(&address, &nonce, removed));
 
 		trace!(target: "miner", "status: {:?}", self.status());
@@ -937,7 +938,7 @@ mod test {
 		let res = txq.add(tx2.clone(), &default_nonce, TransactionOrigin::External);
 
 		// and then there should be only one transaction in current (the one with higher gas_price)
-		assert_eq!(unwrap_tx_err(res), TransactionError::TooCheapToReplace);
+		assert_eq!(res.unwrap(), TransactionImportResult::Current);
 		assert_eq!(txq.status().pending, 1);
 		assert_eq!(txq.status().future, 0);
 		assert_eq!(txq.current.by_priority.len(), 1);
diff --git a/ethstore/src/ethkey.rs b/ethstore/src/ethkey.rs
index eba877397..9d8858b79 100644
--- a/ethstore/src/ethkey.rs
+++ b/ethstore/src/ethkey.rs
@@ -31,3 +31,11 @@ impl From<json::H160> for Address {
 		From::from(a)
 	}
 }
+
+impl<'a> From<&'a json::H160> for Address {
+	fn from(json: &'a json::H160) -> Self {
+		let mut a = [0u8; 20];
+		a.copy_from_slice(json);
+		From::from(a)
+	}
+}
diff --git a/parity/configuration.rs b/parity/configuration.rs
index 3f8202021..e6e6e36a1 100644
--- a/parity/configuration.rs
+++ b/parity/configuration.rs
@@ -200,7 +200,10 @@ impl Configuration {
 		net_path.push("network");
 		ret.config_path = Some(net_path.to_str().unwrap().to_owned());
 		ret.reserved_nodes = self.init_reserved_nodes();
-		ret.reserved_only = self.args.flag_reserved_only;
+
+		if self.args.flag_reserved_only {
+			ret.non_reserved_mode = ::util::network::NonReservedPeerMode::Deny;
+		}
 		ret
 	}
 
diff --git a/parity/main.rs b/parity/main.rs
index dc5457aa1..a44cdf6d3 100644
--- a/parity/main.rs
+++ b/parity/main.rs
@@ -230,6 +230,7 @@ fn execute_client(conf: Configuration, spec: Spec, client_config: ClientConfig)
 		logger: logger.clone(),
 		settings: network_settings.clone(),
 		allow_pending_receipt_query: !conf.args.flag_geth,
+		net_service: service.network(),
 	});
 
 	let dependencies = rpc::Dependencies {
@@ -315,11 +316,11 @@ fn execute_export(conf: Configuration) {
 		udp_port: None,
 		nat_enabled: false,
 		discovery_enabled: false,
-		reserved_only: true,
 		boot_nodes: Vec::new(),
 		use_secret: None,
 		ideal_peers: 0,
 		reserved_nodes: Vec::new(),
+		non_reserved_mode: ::util::network::NonReservedPeerMode::Accept,
 	};
 	let client_config = conf.client_config(&spec);
 
@@ -387,11 +388,11 @@ fn execute_import(conf: Configuration) {
 		udp_port: None,
 		nat_enabled: false,
 		discovery_enabled: false,
-		reserved_only: true,
 		boot_nodes: Vec::new(),
 		use_secret: None,
 		ideal_peers: 0,
 		reserved_nodes: Vec::new(),
+		non_reserved_mode: ::util::network::NonReservedPeerMode::Accept,
 	};
 	let client_config = conf.client_config(&spec);
 
diff --git a/parity/migration.rs b/parity/migration.rs
index 9f1c4c52e..4198f7ed0 100644
--- a/parity/migration.rs
+++ b/parity/migration.rs
@@ -89,6 +89,7 @@ fn current_version(path: &PathBuf) -> Result<u32, Error> {
 /// Writes current database version to the file.
 /// Creates a new file if the version file does not exist yet.
 fn update_version(path: &PathBuf) -> Result<(), Error> {
+	try!(fs::create_dir_all(path));
 	let mut file = try!(File::create(version_file_path(path)));
 	try!(file.write_all(format!("{}", CURRENT_VERSION).as_bytes()));
 	Ok(())
diff --git a/parity/rpc_apis.rs b/parity/rpc_apis.rs
index bf21181a1..251c24d85 100644
--- a/parity/rpc_apis.rs
+++ b/parity/rpc_apis.rs
@@ -25,6 +25,7 @@ use ethcore::client::Client;
 use util::RotatingLogger;
 use ethcore::account_provider::AccountProvider;
 use util::network_settings::NetworkSettings;
+use util::network::NetworkService;
 
 #[cfg(feature="rpc")]
 pub use ethcore_rpc::ConfirmationsQueue;
@@ -89,6 +90,7 @@ pub struct Dependencies {
 	pub logger: Arc<RotatingLogger>,
 	pub settings: Arc<NetworkSettings>,
 	pub allow_pending_receipt_query: bool,
+	pub net_service: Arc<NetworkService<::ethcore::service::SyncMessage>>,
 }
 
 fn to_modules(apis: &[Api]) -> BTreeMap<String, String> {
@@ -163,7 +165,7 @@ pub fn setup_rpc<T: Extendable>(server: T, deps: Arc<Dependencies>, apis: ApiSet
 				server.add_delegate(EthcoreClient::new(&deps.client, &deps.miner, deps.logger.clone(), deps.settings.clone()).to_delegate())
 			},
 			Api::EthcoreSet => {
-				server.add_delegate(EthcoreSetClient::new(&deps.miner).to_delegate())
+				server.add_delegate(EthcoreSetClient::new(&deps.miner, &deps.net_service).to_delegate())
 			},
 			Api::Traces => {
 				server.add_delegate(TracesClient::new(&deps.client, &deps.miner).to_delegate())
diff --git a/rpc/src/v1/impls/ethcore_set.rs b/rpc/src/v1/impls/ethcore_set.rs
index cbd9c4309..66f1a34aa 100644
--- a/rpc/src/v1/impls/ethcore_set.rs
+++ b/rpc/src/v1/impls/ethcore_set.rs
@@ -16,9 +16,11 @@
 
 /// Ethcore-specific rpc interface for operations altering the settings.
 use util::{U256, Address};
+use util::network::{NetworkService, NonReservedPeerMode};
 use std::sync::{Arc, Weak};
 use jsonrpc_core::*;
 use ethcore::miner::MinerService;
+use ethcore::service::SyncMessage;
 use v1::traits::EthcoreSet;
 use v1::types::{Bytes};
 
@@ -27,13 +29,15 @@ pub struct EthcoreSetClient<M> where
 	M: MinerService {
 
 	miner: Weak<M>,
+	net: Weak<NetworkService<SyncMessage>>,
 }
 
 impl<M> EthcoreSetClient<M> where M: MinerService {
 	/// Creates new `EthcoreSetClient`.
-	pub fn new(miner: &Arc<M>) -> Self {
+	pub fn new(miner: &Arc<M>, net: &Arc<NetworkService<SyncMessage>>) -> Self {
 		EthcoreSetClient {
 			miner: Arc::downgrade(miner),
+			net: Arc::downgrade(net),
 		}
 	}
 }
@@ -74,4 +78,32 @@ impl<M> EthcoreSet for EthcoreSetClient<M> where M: MinerService + 'static {
 			to_value(&true)
 		})
 	}
+
+	fn add_reserved_peer(&self, params: Params) -> Result<Value, Error> {
+		from_params::<(String,)>(params).and_then(|(peer,)| {
+			match take_weak!(self.net).add_reserved_peer(&peer) {
+				Ok(()) => to_value(&true),
+				Err(_) => Err(Error::invalid_params()),
+			}
+		})
+	}
+
+	fn remove_reserved_peer(&self, params: Params) -> Result<Value, Error> {
+		from_params::<(String,)>(params).and_then(|(peer,)| {
+			match take_weak!(self.net).remove_reserved_peer(&peer) {
+				Ok(()) => to_value(&true),
+				Err(_) => Err(Error::invalid_params()),
+			}
+		})
+	}
+
+	fn drop_non_reserved_peers(&self, _: Params) -> Result<Value, Error> {
+		take_weak!(self.net).set_non_reserved_mode(NonReservedPeerMode::Deny);
+		to_value(&true)
+	}
+
+	fn accept_non_reserved_peers(&self, _: Params) -> Result<Value, Error> {
+		take_weak!(self.net).set_non_reserved_mode(NonReservedPeerMode::Accept);
+		to_value(&true)
+	}
 }
diff --git a/rpc/src/v1/tests/mocked/ethcore.rs b/rpc/src/v1/tests/mocked/ethcore.rs
index 68c33ecce..a096543e3 100644
--- a/rpc/src/v1/tests/mocked/ethcore.rs
+++ b/rpc/src/v1/tests/mocked/ethcore.rs
@@ -19,11 +19,13 @@ use std::str::FromStr;
 use jsonrpc_core::IoHandler;
 use v1::{Ethcore, EthcoreClient, EthcoreSet, EthcoreSetClient};
 use ethcore::miner::MinerService;
+use ethcore::service::SyncMessage;
 use v1::tests::helpers::TestMinerService;
 use ethcore::client::{TestBlockChainClient};
 use util::numbers::*;
 use rustc_serialize::hex::FromHex;
 use util::log::RotatingLogger;
+use util::network::{NetworkConfiguration, NetworkService};
 use util::network_settings::NetworkSettings;
 
 fn miner_service() -> Arc<TestMinerService> {
@@ -50,21 +52,26 @@ fn settings() -> Arc<NetworkSettings> {
 	})
 }
 
+fn network_service() -> Arc<NetworkService<SyncMessage>> {
+	Arc::new(NetworkService::new(NetworkConfiguration::new()).unwrap())
+}
+
 fn ethcore_client(client: &Arc<TestBlockChainClient>, miner: &Arc<TestMinerService>) -> EthcoreClient<TestBlockChainClient, TestMinerService> {
 	EthcoreClient::new(client, miner, logger(), settings())
 }
 
-fn ethcore_set_client(miner: &Arc<TestMinerService>) -> EthcoreSetClient<TestMinerService> {
-	EthcoreSetClient::new(miner)
+fn ethcore_set_client(miner: &Arc<TestMinerService>, net: &Arc<NetworkService<SyncMessage>>) -> EthcoreSetClient<TestMinerService> {
+	EthcoreSetClient::new(miner, net)
 }
 
 #[test]
 fn rpc_ethcore_extra_data() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_extraData", "params": [], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":"0x01020304","id":1}"#;
@@ -79,9 +86,10 @@ fn rpc_ethcore_default_extra_data() {
 
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_defaultExtraData", "params": [], "id": 1}"#;
 	let response = format!(r#"{{"jsonrpc":"2.0","result":"0x{}","id":1}}"#, misc::version_data().to_hex());
@@ -93,9 +101,10 @@ fn rpc_ethcore_default_extra_data() {
 fn rpc_ethcore_gas_floor_target() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_gasFloorTarget", "params": [], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":"0x3039","id":1}"#;
@@ -107,9 +116,10 @@ fn rpc_ethcore_gas_floor_target() {
 fn rpc_ethcore_min_gas_price() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_minGasPrice", "params": [], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":"0x01312d00","id":1}"#;
@@ -121,9 +131,10 @@ fn rpc_ethcore_min_gas_price() {
 fn rpc_ethcore_set_min_gas_price() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_setMinGasPrice", "params":["0xcd1722f3947def4cf144679da39c4c32bdc35681"], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":true,"id":1}"#;
@@ -136,9 +147,10 @@ fn rpc_ethcore_set_min_gas_price() {
 fn rpc_ethcore_set_gas_floor_target() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_setGasFloorTarget", "params":["0xcd1722f3947def4cf144679da39c4c32bdc35681"], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":true,"id":1}"#;
@@ -151,9 +163,10 @@ fn rpc_ethcore_set_gas_floor_target() {
 fn rpc_ethcore_set_extra_data() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_setExtraData", "params":["0xcd1722f3947def4cf144679da39c4c32bdc35681"], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":true,"id":1}"#;
@@ -166,9 +179,10 @@ fn rpc_ethcore_set_extra_data() {
 fn rpc_ethcore_set_author() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_setAuthor", "params":["0xcd1722f3947def4cf144679da39c4c32bdc35681"], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":true,"id":1}"#;
@@ -181,13 +195,14 @@ fn rpc_ethcore_set_author() {
 fn rpc_ethcore_dev_logs() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let logger = logger();
 	logger.append("a".to_owned());
 	logger.append("b".to_owned());
 	let ethcore = EthcoreClient::new(&client, &miner, logger.clone(), settings()).to_delegate();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore);
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_devLogs", "params":[], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":["b","a"],"id":1}"#;
@@ -199,9 +214,10 @@ fn rpc_ethcore_dev_logs() {
 fn rpc_ethcore_dev_logs_levels() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_devLogsLevels", "params":[], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":"rpc=trace","id":1}"#;
@@ -212,9 +228,10 @@ fn rpc_ethcore_dev_logs_levels() {
 fn rpc_ethcore_set_transactions_limit() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_setTransactionsLimit", "params":[10240240], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":true,"id":1}"#;
@@ -227,9 +244,10 @@ fn rpc_ethcore_set_transactions_limit() {
 fn rpc_ethcore_transactions_limit() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_transactionsLimit", "params":[], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":1024,"id":1}"#;
@@ -241,9 +259,10 @@ fn rpc_ethcore_transactions_limit() {
 fn rpc_ethcore_net_chain() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_netChain", "params":[], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":"testchain","id":1}"#;
@@ -255,9 +274,10 @@ fn rpc_ethcore_net_chain() {
 fn rpc_ethcore_net_max_peers() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_netMaxPeers", "params":[], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":25,"id":1}"#;
@@ -269,9 +289,10 @@ fn rpc_ethcore_net_max_peers() {
 fn rpc_ethcore_net_port() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_netPort", "params":[], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":30303,"id":1}"#;
@@ -283,9 +304,10 @@ fn rpc_ethcore_net_port() {
 fn rpc_ethcore_rpc_settings() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_rpcSettings", "params":[], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":{"enabled":true,"interface":"all","port":8545},"id":1}"#;
@@ -297,9 +319,10 @@ fn rpc_ethcore_rpc_settings() {
 fn rpc_ethcore_node_name() {
 	let miner = miner_service();
 	let client = client_service();
+	let network = network_service();
 	let io = IoHandler::new();
 	io.add_delegate(ethcore_client(&client, &miner).to_delegate());
-	io.add_delegate(ethcore_set_client(&miner).to_delegate());
+	io.add_delegate(ethcore_set_client(&miner, &network).to_delegate());
 
 	let request = r#"{"jsonrpc": "2.0", "method": "ethcore_nodeName", "params":[], "id": 1}"#;
 	let response = r#"{"jsonrpc":"2.0","result":"mynode","id":1}"#;
diff --git a/rpc/src/v1/traits/ethcore_set.rs b/rpc/src/v1/traits/ethcore_set.rs
index 332c505b6..ed4303be1 100644
--- a/rpc/src/v1/traits/ethcore_set.rs
+++ b/rpc/src/v1/traits/ethcore_set.rs
@@ -37,6 +37,18 @@ pub trait EthcoreSet: Sized + Send + Sync + 'static {
 	/// Sets the limits for transaction queue.
 	fn set_transactions_limit(&self, _: Params) -> Result<Value, Error>;
 
+	/// Add a reserved peer.
+	fn add_reserved_peer(&self, _: Params) -> Result<Value, Error>;
+
+	/// Remove a reserved peer.
+	fn remove_reserved_peer(&self, _: Params) -> Result<Value, Error>;
+
+	/// Drop all non-reserved peers.
+	fn drop_non_reserved_peers(&self, _: Params) -> Result<Value, Error>;
+
+	/// Accept non-reserved peers (default behavior)
+	fn accept_non_reserved_peers(&self, _: Params) -> Result<Value, Error>;
+
 	/// Should be used to convert object to io delegate.
 	fn to_delegate(self) -> IoDelegate<Self> {
 		let mut delegate = IoDelegate::new(Arc::new(self));
@@ -45,6 +57,10 @@ pub trait EthcoreSet: Sized + Send + Sync + 'static {
 		delegate.add_method("ethcore_setExtraData", EthcoreSet::set_extra_data);
 		delegate.add_method("ethcore_setAuthor", EthcoreSet::set_author);
 		delegate.add_method("ethcore_setTransactionsLimit", EthcoreSet::set_transactions_limit);
+		delegate.add_method("ethcore_addReservedPeer", EthcoreSet::add_reserved_peer);
+		delegate.add_method("ethcore_removeReservedPeer", EthcoreSet::remove_reserved_peer);
+		delegate.add_method("ethcore_dropNonReservedPeers", EthcoreSet::drop_non_reserved_peers);
+		delegate.add_method("ethcore_acceptNonReservedPeers", EthcoreSet::accept_non_reserved_peers);
 
 		delegate
 	}
diff --git a/util/src/kvdb.rs b/util/src/kvdb.rs
index 7d581fdbc..0911b3471 100644
--- a/util/src/kvdb.rs
+++ b/util/src/kvdb.rs
@@ -20,6 +20,9 @@ use std::default::Default;
 use rocksdb::{DB, Writable, WriteBatch, IteratorMode, DBVector, DBIterator,
 	IndexType, Options, DBCompactionStyle, BlockBasedOptions, Direction};
 
+const DB_FILE_SIZE_BASE: u64 = 10 * 1024 * 1024;
+const DB_FILE_SIZE_MULTIPLIER: i32 = 5;
+
 /// Write transaction. Batches a sequence of put/delete operations for efficiency.
 pub struct DBTransaction {
 	batch: WriteBatch,
@@ -64,7 +67,7 @@ impl DatabaseConfig {
 		DatabaseConfig {
 			cache_size: Some(cache_size),
 			prefix_size: None,
-			max_open_files: 256
+			max_open_files: -1,
 		}
 	}
 }
@@ -74,7 +77,7 @@ impl Default for DatabaseConfig {
 		DatabaseConfig {
 			cache_size: None,
 			prefix_size: None,
-			max_open_files: 256
+			max_open_files: -1,
 		}
 	}
 }
@@ -110,6 +113,8 @@ impl Database {
 		opts.create_if_missing(true);
 		opts.set_use_fsync(false);
 		opts.set_compaction_style(DBCompactionStyle::DBUniversalCompaction);
+		opts.set_target_file_size_base(DB_FILE_SIZE_BASE);
+		opts.set_target_file_size_multiplier(DB_FILE_SIZE_MULTIPLIER);
 		if let Some(cache_size) = config.cache_size {
 			// half goes to read cache
 			opts.set_block_cache_size_mb(cache_size as u64 / 2);
diff --git a/util/src/network/host.rs b/util/src/network/host.rs
index aacfc3fcb..03ba07544 100644
--- a/util/src/network/host.rs
+++ b/util/src/network/host.rs
@@ -14,9 +14,9 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-use std::net::{SocketAddr};
-use std::collections::{HashMap};
-use std::str::{FromStr};
+use std::net::SocketAddr;
+use std::collections::{HashMap, HashSet};
+use std::str::FromStr;
 use std::sync::*;
 use std::sync::atomic::{AtomicUsize, AtomicBool, Ordering as AtomicOrdering};
 use std::ops::*;
@@ -35,7 +35,7 @@ use rlp::*;
 use network::session::{Session, SessionData};
 use error::*;
 use io::*;
-use network::{NetworkProtocolHandler, PROTOCOL_VERSION};
+use network::{NetworkProtocolHandler, NonReservedPeerMode, PROTOCOL_VERSION};
 use network::node_table::*;
 use network::stats::NetworkStats;
 use network::error::{NetworkError, DisconnectReason};
@@ -65,8 +65,6 @@ pub struct NetworkConfiguration {
 	pub nat_enabled: bool,
 	/// Enable discovery
 	pub discovery_enabled: bool,
-	/// Pin to reserved nodes only
-	pub reserved_only: bool,
 	/// List of initial node addresses
 	pub boot_nodes: Vec<String>,
 	/// Use provided node key instead of default
@@ -75,6 +73,8 @@ pub struct NetworkConfiguration {
 	pub ideal_peers: u32,
 	/// List of reserved node addresses.
 	pub reserved_nodes: Vec<String>,
+	/// The non-reserved peer mode.
+	pub non_reserved_mode: NonReservedPeerMode,
 }
 
 impl Default for NetworkConfiguration {
@@ -93,11 +93,11 @@ impl NetworkConfiguration {
 			udp_port: None,
 			nat_enabled: true,
 			discovery_enabled: true,
-			reserved_only: false,
 			boot_nodes: Vec::new(),
 			use_secret: None,
 			ideal_peers: 25,
 			reserved_nodes: Vec::new(),
+			non_reserved_mode: NonReservedPeerMode::Accept,
 		}
 	}
 
@@ -191,13 +191,15 @@ pub struct NetworkContext<'s, Message> where Message: Send + Sync + Clone + 'sta
 	sessions: Arc<RwLock<Slab<SharedSession>>>,
 	session: Option<SharedSession>,
 	session_id: Option<StreamToken>,
+	reserved_peers: &'s HashSet<NodeId>,
 }
 
 impl<'s, Message> NetworkContext<'s, Message> where Message: Send + Sync + Clone + 'static, {
 	/// Create a new network IO access point. Takes references to all the data that can be updated within the IO handler.
 	fn new(io: &'s IoContext<NetworkIoMessage<Message>>,
 		protocol: ProtocolId,
-		session: Option<SharedSession>, sessions: Arc<RwLock<Slab<SharedSession>>>) -> NetworkContext<'s, Message> {
+		session: Option<SharedSession>, sessions: Arc<RwLock<Slab<SharedSession>>>,
+		reserved_peers: &'s HashSet<NodeId>) -> NetworkContext<'s, Message> {
 		let id = session.as_ref().map(|s| s.lock().unwrap().token());
 		NetworkContext {
 			io: io,
@@ -205,6 +207,7 @@ impl<'s, Message> NetworkContext<'s, Message> where Message: Send + Sync + Clone
 			session_id: id,
 			session: session,
 			sessions: sessions,
+			reserved_peers: reserved_peers,
 		}
 	}
 
@@ -237,7 +240,7 @@ impl<'s, Message> NetworkContext<'s, Message> where Message: Send + Sync + Clone
 		self.io.message(NetworkIoMessage::User(msg));
 	}
 
-	/// Send an IO message
+	/// Get an IoChannel.
 	pub fn io_channel(&self) -> IoChannel<NetworkIoMessage<Message>> {
 		self.io.channel()
 	}
@@ -335,7 +338,7 @@ pub struct Host<Message> where Message: Send + Sync + Clone {
 	timers: RwLock<HashMap<TimerToken, ProtocolTimer>>,
 	timer_counter: RwLock<usize>,
 	stats: Arc<NetworkStats>,
-	pinned_nodes: Vec<NodeId>,
+	reserved_nodes: RwLock<HashSet<NodeId>>,
 	num_sessions: AtomicUsize,
 	stopping: AtomicBool,
 }
@@ -390,28 +393,28 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 			timers: RwLock::new(HashMap::new()),
 			timer_counter: RwLock::new(USER_TIMER),
 			stats: stats,
-			pinned_nodes: Vec::new(),
+			reserved_nodes: RwLock::new(HashSet::new()),
 			num_sessions: AtomicUsize::new(0),
 			stopping: AtomicBool::new(false),
 		};
 
 		for n in boot_nodes {
-			// don't pin boot nodes.
-			host.add_node(&n, false);
+			host.add_node(&n);
 		}
 
 		for n in reserved_nodes {
-			host.add_node(&n, true);
+			if let Err(e) = host.add_reserved_node(&n) {
+				debug!(target: "network", "Error parsing node id: {}: {:?}", n, e);
+			}
 		}
 		Ok(host)
 	}
 
-	pub fn add_node(&mut self, id: &str, pin: bool) {
+	pub fn add_node(&mut self, id: &str) {
 		match Node::from_str(id) {
 			Err(e) => { debug!(target: "network", "Could not add node {}: {:?}", id, e); },
 			Ok(n) => {
 				let entry = NodeEntry { endpoint: n.endpoint.clone(), id: n.id.clone() };
-				if pin { self.pinned_nodes.push(n.id.clone()) }
 
 				self.nodes.write().unwrap().add_node(n);
 				if let Some(ref mut discovery) = *self.discovery.lock().unwrap() {
@@ -421,6 +424,56 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 		}
 	}
 
+	pub fn add_reserved_node(&self, id: &str) -> Result<(), UtilError> {
+		let n = try!(Node::from_str(id));
+
+		let entry = NodeEntry { endpoint: n.endpoint.clone(), id: n.id.clone() };
+		self.reserved_nodes.write().unwrap().insert(n.id.clone());
+
+		if let Some(ref mut discovery) = *self.discovery.lock().unwrap() {
+			discovery.add_node(entry);
+		}
+
+		Ok(())
+	}
+
+	pub fn set_non_reserved_mode(&self, mode: NonReservedPeerMode, io: &IoContext<NetworkIoMessage<Message>>) {
+		let mut info = self.info.write().unwrap();
+
+		if info.config.non_reserved_mode != mode {
+			info.config.non_reserved_mode = mode.clone();
+			drop(info);
+			if let NonReservedPeerMode::Deny = mode {
+				// disconnect all non-reserved peers here.
+				let reserved: HashSet<NodeId> = self.reserved_nodes.read().unwrap().clone();
+				let mut to_kill = Vec::new();
+				for e in self.sessions.write().unwrap().iter_mut() {
+					let mut s = e.lock().unwrap();
+					{
+						let id = s.id();
+						if id.is_some() && reserved.contains(id.unwrap()) {
+							continue;
+						}
+					}
+
+					s.disconnect(io, DisconnectReason::ClientQuit);
+					to_kill.push(s.token());
+				}
+				for p in to_kill {
+					trace!(target: "network", "Disconnecting on reserved-only mode: {}", p);
+					self.kill_connection(p, io, false);
+				}
+			}
+		}
+	}
+
+	pub fn remove_reserved_node(&self, id: &str) -> Result<(), UtilError> {
+		let n = try!(Node::from_str(id));
+		self.reserved_nodes.write().unwrap().remove(&n.id);
+
+		Ok(())
+	}
+
 	pub fn client_version() -> String {
 		version()
 	}
@@ -483,7 +536,7 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 		// Initialize discovery.
 		let discovery = {
 			let info = self.info.read().unwrap();
-			if info.config.discovery_enabled && !info.config.reserved_only {
+			if info.config.discovery_enabled && info.config.non_reserved_mode == NonReservedPeerMode::Accept {
 				Some(Discovery::new(&info.keys, public_endpoint.address.clone(), public_endpoint, DISCOVERY))
 			} else { None }
 		};
@@ -540,17 +593,26 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 	}
 
 	fn connect_peers(&self, io: &IoContext<NetworkIoMessage<Message>>) {
-		if self.info.read().unwrap().capabilities.is_empty() {
-			return;
-		}
-		let ideal_peers = { self.info.read().unwrap().config.ideal_peers };
-		let pin = { self.info.read().unwrap().config.reserved_only };
-		let session_count = self.session_count();
-		if session_count >= ideal_peers as usize + self.pinned_nodes.len() {
-			// check if all pinned nodes are connected.
-			if self.pinned_nodes.iter().all(|n| self.have_session(n) && self.connecting_to(n)) {
+		let (ideal_peers, mut pin) = {
+			let info = self.info.read().unwrap();
+			if info.capabilities.is_empty() {
 				return;
 			}
+			let config = &info.config;
+
+			(config.ideal_peers, config.non_reserved_mode == NonReservedPeerMode::Deny)
+		};
+
+		let session_count = self.session_count();
+		let reserved_nodes = self.reserved_nodes.read().unwrap();
+		if session_count >= ideal_peers as usize + reserved_nodes.len() {
+			// check if all pinned nodes are connected.
+			if reserved_nodes.iter().all(|n| self.have_session(n) && self.connecting_to(n)) {
+				return;
+			}
+
+			// if not, only attempt connect to reserved peers
+			pin = true;
 		}
 
 		let handshake_count = self.handshake_count();
@@ -562,7 +624,7 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 
 		// iterate over all nodes, reserved ones coming first.
 		// if we are pinned to only reserved nodes, ignore all others.
-		let nodes = self.pinned_nodes.iter().cloned().chain(if !pin {
+		let nodes = reserved_nodes.iter().cloned().chain(if !pin {
 			self.nodes.read().unwrap().nodes()
 		} else {
 			Vec::new()
@@ -696,11 +758,20 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 						self.num_sessions.fetch_add(1, AtomicOrdering::SeqCst);
 						if !s.info.originated {
 							let session_count = self.session_count();
-							let ideal_peers = { self.info.read().unwrap().config.ideal_peers };
-							if session_count >= ideal_peers as usize {
-								s.disconnect(io, DisconnectReason::TooManyPeers);
-								return;
+							let reserved_nodes = self.reserved_nodes.read().unwrap();
+							let (ideal_peers, reserved_only) = {
+								let info = self.info.read().unwrap();
+								(info.config.ideal_peers, info.config.non_reserved_mode == NonReservedPeerMode::Deny)
+							};
+
+							if session_count >= ideal_peers as usize || reserved_only {
+								// only proceed if the connecting peer is reserved.
+								if !reserved_nodes.contains(s.id().unwrap()) {
+									s.disconnect(io, DisconnectReason::TooManyPeers);
+									return;
+								}
 							}
+
 							// Add it no node table
 							if let Ok(address) = s.remote_addr() {
 								let entry = NodeEntry { id: s.id().unwrap().clone(), endpoint: NodeEndpoint { address: address, udp_port: address.port() } };
@@ -735,14 +806,17 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 		if kill {
 			self.kill_connection(token, io, true);
 		}
+		let handlers = self.handlers.read().unwrap();
 		for p in ready_data {
-			let h = self.handlers.read().unwrap().get(p).unwrap().clone();
+			let h = handlers.get(p).unwrap().clone();
 			self.stats.inc_sessions();
-			h.connected(&NetworkContext::new(io, p, session.clone(), self.sessions.clone()), &token);
+			let reserved = self.reserved_nodes.read().unwrap();
+			h.connected(&NetworkContext::new(io, p, session.clone(), self.sessions.clone(), &reserved), &token);
 		}
 		for (p, packet_id, data) in packet_data {
-			let h = self.handlers.read().unwrap().get(p).unwrap().clone();
-			h.read(&NetworkContext::new(io, p, session.clone(), self.sessions.clone()), &token, packet_id, &data[1..]);
+			let h = handlers.get(p).unwrap().clone();
+			let reserved = self.reserved_nodes.read().unwrap();
+			h.read(&NetworkContext::new(io, p, session.clone(), self.sessions.clone(), &reserved), &token, packet_id, &data[1..]);
 		}
 	}
 
@@ -783,7 +857,8 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 		}
 		for p in to_disconnect {
 			let h = self.handlers.read().unwrap().get(p).unwrap().clone();
-			h.disconnected(&NetworkContext::new(io, p, expired_session.clone(), self.sessions.clone()), &token);
+			let reserved = self.reserved_nodes.read().unwrap();
+			h.disconnected(&NetworkContext::new(io, p, expired_session.clone(), self.sessions.clone(), &reserved), &token);
 		}
 		if deregister {
 			io.deregister_stream(token).unwrap_or_else(|e| debug!("Error deregistering stream: {:?}", e));
@@ -886,7 +961,10 @@ impl<Message> IoHandler<NetworkIoMessage<Message>> for Host<Message> where Messa
 			_ => match self.timers.read().unwrap().get(&token).cloned() {
 				Some(timer) => match self.handlers.read().unwrap().get(timer.protocol).cloned() {
 					None => { warn!(target: "network", "No handler found for protocol: {:?}", timer.protocol) },
-					Some(h) => { h.timeout(&NetworkContext::new(io, timer.protocol, None, self.sessions.clone()), timer.token); }
+					Some(h) => {
+						let reserved = self.reserved_nodes.read().unwrap();
+						h.timeout(&NetworkContext::new(io, timer.protocol, None, self.sessions.clone(), &reserved), timer.token);
+					}
 				},
 				None => { warn!("Unknown timer token: {}", token); } // timer is not registerd through us
 			}
@@ -904,7 +982,8 @@ impl<Message> IoHandler<NetworkIoMessage<Message>> for Host<Message> where Messa
 				ref versions
 			} => {
 				let h = handler.clone();
-				h.initialize(&NetworkContext::new(io, protocol, None, self.sessions.clone()));
+				let reserved = self.reserved_nodes.read().unwrap();
+				h.initialize(&NetworkContext::new(io, protocol, None, self.sessions.clone(), &reserved));
 				self.handlers.write().unwrap().insert(protocol, h);
 				let mut info = self.info.write().unwrap();
 				for v in versions {
@@ -946,8 +1025,9 @@ impl<Message> IoHandler<NetworkIoMessage<Message>> for Host<Message> where Messa
 				self.kill_connection(*peer, io, false);
 			},
 			NetworkIoMessage::User(ref message) => {
+				let reserved = self.reserved_nodes.read().unwrap();
 				for (p, h) in self.handlers.read().unwrap().iter() {
-					h.message(&NetworkContext::new(io, p, None, self.sessions.clone()), &message);
+					h.message(&NetworkContext::new(io, p, None, self.sessions.clone(), &reserved), &message);
 				}
 			}
 		}
diff --git a/util/src/network/mod.rs b/util/src/network/mod.rs
index d074e6631..d59ab63b1 100644
--- a/util/src/network/mod.rs
+++ b/util/src/network/mod.rs
@@ -14,8 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Network and general IO module. 
-//! 
+//! Network and general IO module.
+//!
 //! Example usage for craeting a network service and adding an IO handler:
 //!
 //! ```rust
@@ -112,3 +112,22 @@ pub trait NetworkProtocolHandler<Message>: Sync + Send where Message: Send + Syn
 	fn message(&self, _io: &NetworkContext<Message>, _message: &Message) {}
 }
 
+/// Non-reserved peer modes.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum NonReservedPeerMode {
+	/// Accept them. This is the default.
+	Accept,
+	/// Deny them.
+	Deny,
+}
+
+impl NonReservedPeerMode {
+	/// Attempt to parse the peer mode from a string.
+	pub fn parse(s: &str) -> Option<Self> {
+		match s {
+			"accept" => Some(NonReservedPeerMode::Accept),
+			"deny" => Some(NonReservedPeerMode::Deny),
+			_ => None,
+		}
+	}
+}
\ No newline at end of file
diff --git a/util/src/network/service.rs b/util/src/network/service.rs
index e8db354d4..353a24bbe 100644
--- a/util/src/network/service.rs
+++ b/util/src/network/service.rs
@@ -18,9 +18,9 @@ use std::sync::*;
 use error::*;
 use panics::*;
 use network::{NetworkProtocolHandler, NetworkConfiguration};
-use network::error::{NetworkError};
+use network::error::NetworkError;
 use network::host::{Host, NetworkIoMessage, ProtocolId};
-use network::stats::{NetworkStats};
+use network::stats::NetworkStats;
 use io::*;
 
 /// IO Service with networking
@@ -111,6 +111,35 @@ impl<Message> NetworkService<Message> where Message: Send + Sync + Clone + 'stat
 		*host = None;
 		Ok(())
 	}
+
+	/// Try to add a reserved peer.
+	pub fn add_reserved_peer(&self, peer: &str) -> Result<(), UtilError> {
+		let host = self.host.read().unwrap();
+		if let Some(ref host) = *host {
+			host.add_reserved_node(peer)
+		} else {
+			Ok(())
+		}
+	}
+
+	/// Try to remove a reserved peer.
+	pub fn remove_reserved_peer(&self, peer: &str) -> Result<(), UtilError> {
+		let host = self.host.read().unwrap();
+		if let Some(ref host) = *host {
+			host.remove_reserved_node(peer)
+		} else {
+			Ok(())
+		}
+	}
+
+	/// Set the non-reserved peer mode.
+	pub fn set_non_reserved_mode(&self, mode: ::network::NonReservedPeerMode) {
+		let host = self.host.read().unwrap();
+		if let Some(ref host) = *host {
+			let io_ctxt = IoContext::new(self.io_service.channel(), 0);
+			host.set_non_reserved_mode(mode, &io_ctxt);
+		}
+	}
 }
 
 impl<Message> MayPanic for NetworkService<Message> where Message: Send + Sync + Clone + 'static {