diff --git a/ethcore/src/client/client.rs b/ethcore/src/client/client.rs
index 0c50d85aa..ef4415934 100644
--- a/ethcore/src/client/client.rs
+++ b/ethcore/src/client/client.rs
@@ -45,6 +45,7 @@ use block::*;
 use transaction::{LocalizedTransaction, SignedTransaction, Action};
 use blockchain::extras::TransactionAddress;
 use types::filter::Filter;
+use types::mode::Mode as IpcMode;
 use log_entry::LocalizedLogEntry;
 use verification::queue::BlockQueue;
 use blockchain::{BlockChain, BlockProvider, TreeRoute, ImportRoute};
@@ -123,7 +124,7 @@ impl SleepState {
 /// Blockchain database client backed by a persistent database. Owns and manages a blockchain and a block queue.
 /// Call `import_block()` to import a block asynchronously; `flush_queue()` flushes the queue.
 pub struct Client {
-	mode: Mode,
+	mode: Mutex<Mode>,
 	chain: RwLock<Arc<BlockChain>>,
 	tracedb: RwLock<TraceDB<BlockChain>>,
 	engine: Arc<Engine>,
@@ -221,7 +222,7 @@ impl Client {
 		let client = Client {
 			sleep_state: Mutex::new(SleepState::new(awake)),
 			liveness: AtomicBool::new(awake),
-			mode: config.mode.clone(),
+			mode: Mutex::new(config.mode.clone()),
 			chain: RwLock::new(chain),
 			tracedb: tracedb,
 			engine: engine,
@@ -614,7 +615,8 @@ impl Client {
 		self.block_queue.collect_garbage();
 		self.tracedb.read().collect_garbage();
 
-		match self.mode {
+		let mode = self.mode.lock().clone();
+		match mode {
 			Mode::Dark(timeout) => {
 				let mut ss = self.sleep_state.lock();
 				if let Some(t) = ss.last_activity {
@@ -838,12 +840,24 @@ impl BlockChainClient for Client {
 	}
 
 	fn keep_alive(&self) {
-		if self.mode != Mode::Active {
+		let mode = self.mode.lock().clone();
+		if mode != Mode::Active {
 			self.wake_up();
 			(*self.sleep_state.lock()).last_activity = Some(Instant::now());
 		}
 	}
 
+	fn mode(&self) -> IpcMode { self.mode.lock().clone().into() }
+
+	fn set_mode(&self, mode: IpcMode) {
+		*self.mode.lock() = mode.clone().into();
+		match mode {
+			IpcMode::Active => self.wake_up(),
+			IpcMode::Off => self.sleep(),
+			_ => {(*self.sleep_state.lock()).last_activity = Some(Instant::now()); }
+		}
+	}
+
 	fn best_block_header(&self) -> Bytes {
 		self.chain.read().best_block_header()
 	}
diff --git a/ethcore/src/client/config.rs b/ethcore/src/client/config.rs
index 850e5c938..c4aeba8a4 100644
--- a/ethcore/src/client/config.rs
+++ b/ethcore/src/client/config.rs
@@ -76,6 +76,8 @@ pub enum Mode {
 	/// Goes offline after RLP is inactive for some (given) time and
 	/// stays inactive.
 	Dark(Duration),
+	/// Always off.
+	Off,
 }
 
 impl Default for Mode {
diff --git a/ethcore/src/client/test_client.rs b/ethcore/src/client/test_client.rs
index 11a9286da..29a48f02f 100644
--- a/ethcore/src/client/test_client.rs
+++ b/ethcore/src/client/test_client.rs
@@ -37,6 +37,7 @@ use error::{ImportResult};
 use evm::{Factory as EvmFactory, VMType, Schedule};
 use miner::{Miner, MinerService, TransactionImportResult};
 use spec::Spec;
+use types::mode::Mode;
 
 use verification::queue::QueueInfo;
 use block::{OpenBlock, SealedBlock};
@@ -625,4 +626,8 @@ impl BlockChainClient for TestBlockChainClient {
 	fn pending_transactions(&self) -> Vec<SignedTransaction> {
 		self.miner.pending_transactions(self.chain_info().best_block_number)
 	}
+
+	fn mode(&self) -> Mode { Mode::Active }
+
+	fn set_mode(&self, _: Mode) { unimplemented!(); }
 }
diff --git a/ethcore/src/client/traits.rs b/ethcore/src/client/traits.rs
index 8f6532c1a..d7844ba3d 100644
--- a/ethcore/src/client/traits.rs
+++ b/ethcore/src/client/traits.rs
@@ -38,6 +38,7 @@ use block_import_error::BlockImportError;
 use ipc::IpcConfig;
 use types::blockchain_info::BlockChainInfo;
 use types::block_status::BlockStatus;
+use types::mode::Mode;
 
 #[ipc(client_ident="RemoteClient")]
 /// Blockchain database client. Owns and manages a blockchain and a block queue.
@@ -225,6 +226,10 @@ pub trait BlockChainClient : Sync + Send {
 		let (corpus, _) = raw_corpus.split_at(raw_len-raw_len/40);
 		Histogram::new(corpus, bucket_number)
 	}
+
+	fn mode(&self) -> Mode;
+
+	fn set_mode(&self, mode: Mode);
 }
 
 /// Extended client interface used for mining
diff --git a/ethcore/src/types/mod.rs.in b/ethcore/src/types/mod.rs.in
index 32c7faabe..1d2cdb3c0 100644
--- a/ethcore/src/types/mod.rs.in
+++ b/ethcore/src/types/mod.rs.in
@@ -33,3 +33,4 @@ pub mod transaction_import;
 pub mod block_import_error;
 pub mod restoration_status;
 pub mod snapshot_manifest;
+pub mod mode;
\ No newline at end of file
diff --git a/ethcore/src/types/mode.rs b/ethcore/src/types/mode.rs
new file mode 100644
index 000000000..b48a92a89
--- /dev/null
+++ b/ethcore/src/types/mode.rs
@@ -0,0 +1,55 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Mode type
+
+pub use std::time::Duration;
+use client::Mode as ClientMode;
+
+/// IPC-capable shadow-type for client::config::Mode
+#[derive(Clone, Binary)]
+pub enum Mode {
+	/// Same as ClientMode::Off.
+	Off,
+	/// Same as ClientMode::Dark; values in seconds.
+	Dark(u64),
+	/// Same as ClientMode::Passive; values in seconds.
+	Passive(u64, u64),
+	/// Same as ClientMode::Active.
+	Active,
+}
+
+impl From<ClientMode> for Mode {
+	fn from(mode: ClientMode) -> Self {
+		match mode {
+			ClientMode::Off => Mode::Off,
+			ClientMode::Dark(timeout) => Mode::Dark(timeout.as_secs()),
+			ClientMode::Passive(timeout, alarm) => Mode::Passive(timeout.as_secs(), alarm.as_secs()),
+			ClientMode::Active => Mode::Active,
+		}
+	}
+}
+
+impl From<Mode> for ClientMode {
+	fn from(mode: Mode) -> Self {
+		match mode {
+			Mode::Off => ClientMode::Off,
+			Mode::Dark(timeout) => ClientMode::Dark(Duration::from_secs(timeout)),
+			Mode::Passive(timeout, alarm) => ClientMode::Passive(Duration::from_secs(timeout), Duration::from_secs(alarm)),
+			Mode::Active => ClientMode::Active,
+		}
+	}
+}
\ No newline at end of file
diff --git a/js/src/api/rpc/ethcore/ethcore.js b/js/src/api/rpc/ethcore/ethcore.js
index b775208f0..663143f0d 100644
--- a/js/src/api/rpc/ethcore/ethcore.js
+++ b/js/src/api/rpc/ethcore/ethcore.js
@@ -91,6 +91,11 @@ export default class Ethcore {
       .then(outNumber);
   }
 
+  mode () {
+    return this._transport
+      .execute('ethcore_mode');
+  }
+
   netChain () {
     return this._transport
       .execute('ethcore_netChain');
@@ -161,6 +166,11 @@ export default class Ethcore {
       .execute('ethcore_setMinGasPrice', inNumber16(quantity));
   }
 
+  setMode (mode) {
+    return this._transport
+      .execute('ethcore_setMode', mode);
+  }
+
   setTransactionsLimit (quantity) {
     return this._transport
       .execute('ethcore_setTransactionsLimit', inNumber16(quantity));
diff --git a/js/src/jsonrpc/interfaces/ethcore.js b/js/src/jsonrpc/interfaces/ethcore.js
index 07c6fed2c..c81a82f76 100644
--- a/js/src/jsonrpc/interfaces/ethcore.js
+++ b/js/src/jsonrpc/interfaces/ethcore.js
@@ -156,6 +156,15 @@ export default {
     }
   },
 
+  mode: {
+    desc: 'Get the mode. Results one of: "active", "passive", "dark", "off".',
+    params: [],
+    returns: {
+      type: String,
+      desc: 'The mode'
+    }
+  },
+
   netChain: {
     desc: 'Returns the name of the connected chain.',
     params: [],
@@ -307,6 +316,20 @@ export default {
     }
   },
 
+  setMode: {
+    desc: 'Changes the mode',
+    params: [
+      {
+        type: String,
+        desc: 'The mode to set, one of "active", "passive", "dark", "off"'
+      }
+    ],
+    returns: {
+      type: Boolean,
+      desc: 'True if the call succeeded'
+    }
+  },
+
   setTransactionsLimit: {
     desc: 'Changes limit for transactions in queue.',
     params: [
diff --git a/rpc/src/v1/impls/ethcore.rs b/rpc/src/v1/impls/ethcore.rs
index bcb067d03..dbb27037c 100644
--- a/rpc/src/v1/impls/ethcore.rs
+++ b/rpc/src/v1/impls/ethcore.rs
@@ -30,6 +30,7 @@ use ethsync::{SyncProvider, ManageNetwork};
 use ethcore::miner::MinerService;
 use ethcore::client::{MiningBlockChainClient};
 use ethcore::ids::BlockID;
+use ethcore::mode::Mode;
 
 use jsonrpc_core::Error;
 use v1::traits::Ethcore;
@@ -343,4 +344,13 @@ impl<C, M, S: ?Sized, F> Ethcore for EthcoreClient<C, M, S, F> where
 			.into()
 		)
 	}
+
+	fn mode(&self) -> Result<String, Error> {
+		Ok(match take_weak!(self.client).mode() {
+			Mode::Off => "off",
+			Mode::Dark(..) => "dark",
+			Mode::Passive(..) => "passive",
+			Mode::Active => "active",
+		}.into())
+	}
 }
diff --git a/rpc/src/v1/impls/ethcore_set.rs b/rpc/src/v1/impls/ethcore_set.rs
index 7bebf9bbb..27464cff3 100644
--- a/rpc/src/v1/impls/ethcore_set.rs
+++ b/rpc/src/v1/impls/ethcore_set.rs
@@ -19,6 +19,7 @@ use std::sync::{Arc, Weak};
 use jsonrpc_core::*;
 use ethcore::miner::MinerService;
 use ethcore::client::MiningBlockChainClient;
+use ethcore::mode::Mode;
 use ethsync::ManageNetwork;
 use v1::helpers::errors;
 use v1::traits::EthcoreSet;
@@ -147,4 +148,15 @@ impl<C, M> EthcoreSet for EthcoreSetClient<C, M> where
 		take_weak!(self.net).stop_network();
 		Ok(true)
 	}
+
+	fn set_mode(&self, mode: String) -> Result<bool, Error> {
+		take_weak!(self.client).set_mode(match mode.as_str() {
+			"off" => Mode::Off,
+			"dark" => Mode::Dark(300),
+			"passive" => Mode::Passive(300, 3600),
+			"active" => Mode::Active,
+			e => { return Err(errors::invalid_params("mode", e.to_owned())); },
+		});
+		Ok(true)
+	}
 }
diff --git a/rpc/src/v1/traits/ethcore.rs b/rpc/src/v1/traits/ethcore.rs
index 8ffc4a325..18279d364 100644
--- a/rpc/src/v1/traits/ethcore.rs
+++ b/rpc/src/v1/traits/ethcore.rs
@@ -129,5 +129,9 @@ build_rpc_trait! {
 		/// Returns next nonce for particular sender. Should include all transactions in the queue.
 		#[rpc(name = "ethcore_nextNonce")]
 		fn next_nonce(&self, H160) -> Result<U256, Error>;
+
+		/// Get the mode. Results one of: "active", "passive", "dark", "off".
+		#[rpc(name = "ethcore_mode")]
+		fn mode(&self) -> Result<String, Error>;
 	}
 }
diff --git a/rpc/src/v1/traits/ethcore_set.rs b/rpc/src/v1/traits/ethcore_set.rs
index 9946314d6..9c0d3d5d4 100644
--- a/rpc/src/v1/traits/ethcore_set.rs
+++ b/rpc/src/v1/traits/ethcore_set.rs
@@ -69,11 +69,19 @@ build_rpc_trait! {
 		fn accept_non_reserved_peers(&self) -> Result<bool, Error>;
 
 		/// Start the network.
+		/// 
+		/// Deprecated. Use `set_mode("active")` instead.
 		#[rpc(name = "ethcore_startNetwork")]
 		fn start_network(&self) -> Result<bool, Error>;
 
 		/// Stop the network.
+		///
+		/// Deprecated. Use `set_mode("off")` instead.
 		#[rpc(name = "ethcore_stopNetwork")]
 		fn stop_network(&self) -> Result<bool, Error>;
+
+		/// Set the mode. Argument must be one of: "active", "passive", "dark", "off".
+		#[rpc(name = "ethcore_setMode")]
+		fn set_mode(&self, String) -> Result<bool, Error>;
 	}
 }
\ No newline at end of file