diff --git a/etc/sample.conf b/etc/sample.conf
index 0aacb5b6..7932bb9e 100644
--- a/etc/sample.conf
+++ b/etc/sample.conf
@@ -56,7 +56,6 @@ selfish: false
 headers: true
 compact: true
 bip151: true
-no-discovery: false
 listen: true
 max-outbound: 8
 max-inbound: 30
diff --git a/lib/net/peer.js b/lib/net/peer.js
index 57f59def..e68bb7e3 100644
--- a/lib/net/peer.js
+++ b/lib/net/peer.js
@@ -1482,15 +1482,32 @@ Peer.prototype.getTX = function getTX(hashes) {
 Peer.prototype.readPacket = co(function* readPacket(packet) {
   var unlock;
 
+  if (this.destroyed)
+    return;
+
+  // The "pre-handshake" packets get
+  // to bypass the lock, since they
+  // are meant to change the way input
+  // is handled at a low level. They
+  // must be handled immediately.
   switch (packet.type) {
     case packetTypes.ENCINIT:
     case packetTypes.ENCACK:
-      return yield this.handlePacket(packet);
+    case packetTypes.AUTHCHALLENGE:
+    case packetTypes.AUTHREPLY:
+    case packetTypes.AUTHPROPOSE:
+      try {
+        this.socket.pause();
+        yield this.handlePacket(packet);
+      } finally {
+        this.socket.resume();
+      }
+      break;
     default:
       unlock = yield this.locker.lock();
       try {
         this.socket.pause();
-        return yield this.handlePacket(packet);
+        yield this.handlePacket(packet);
       } finally {
         this.socket.resume();
         unlock();
@@ -1516,7 +1533,7 @@ Peer.prototype.handlePacket = co(function* handlePacket(packet) {
       && !this.bip151.completed
       && packet.type !== packetTypes.ENCINIT
       && packet.type !== packetTypes.ENCACK) {
-    this.bip151.reject(new Error('Message before handshake.'));
+    this.bip151.reject(new Error('Message before BIP151 handshake.'));
   }
 
   if (this.bip150
@@ -1525,7 +1542,7 @@ Peer.prototype.handlePacket = co(function* handlePacket(packet) {
       && packet.type !== packetTypes.AUTHCHALLENGE
       && packet.type !== packetTypes.AUTHREPLY
       && packet.type !== packetTypes.AUTHPROPOSE) {
-    this.bip150.reject(new Error('Message before auth.'));
+    this.bip150.reject(new Error('Message before BIP150 auth.'));
   }
 
   entry = this.fulfill(packet);
@@ -1715,6 +1732,13 @@ Peer.prototype.handlePong = co(function* handlePong(packet) {
  */
 
 Peer.prototype.handleSendHeaders = co(function* handleSendHeaders(packet) {
+  if (this.preferHeaders) {
+    this.logger.debug(
+      'Peer sent a duplicate sendheaders (%s).',
+      this.hostname());
+    return;
+  }
+
   this.preferHeaders = true;
 });
 
@@ -1793,27 +1817,35 @@ Peer.prototype.handleFeeFilter = co(function* handleFeeFilter(packet) {
 Peer.prototype.handleSendCmpct = co(function* handleSendCmpct(packet) {
   var max = this.options.witness ? 2 : 1;
 
+  // Core witness nodes send this twice
+  // with both version 1 and 2 (why
+  // would you even _want_ non-witness
+  // blocks if you use segwit??).
+  if (this.compactMode !== -1) {
+    this.logger.info(
+      'Peer sent a duplicate sendcmpct (%s).',
+      this.hostname());
+    return;
+  }
+
   if (packet.version > max) {
     // Ignore
-    this.logger.info('Peer request compact blocks version %d (%s).',
+    this.logger.info(
+      'Peer request compact blocks version %d (%s).',
       packet.version, this.hostname());
     return;
   }
 
   if (packet.mode > 1) {
-    this.logger.info('Peer request compact blocks mode %d (%s).',
+    this.logger.info(
+      'Peer request compact blocks mode %d (%s).',
       packet.mode, this.hostname());
     return;
   }
 
-  // Core witness nodes send this twice
-  // with both version 1 and 2 (why
-  // would you even _want_ non-witness
-  // blocks if you use segwit??).
-  if (this.compactMode !== -1)
-    return;
-
-  this.logger.info('Peer initialized compact blocks (%s).', this.hostname());
+  this.logger.info(
+    'Peer initialized compact blocks (%s).',
+    this.hostname());
 
   this.compactMode = packet.mode;
   this.compactWitness = packet.version === 2;
diff --git a/lib/net/pool.js b/lib/net/pool.js
index 61d18cb3..d110aa81 100644
--- a/lib/net/pool.js
+++ b/lib/net/pool.js
@@ -58,8 +58,6 @@ var packetTypes = packets.types;
  * headers, hashes, utxos, or transactions to peers.
  * @param {Boolean?} options.broadcast - Whether to automatically broadcast
  * transactions accepted to our mempool.
- * @param {Boolean} options.noDiscovery - Automatically discover new
- * peers.
  * @param {String[]} options.seeds
  * @param {Function?} options.createSocket - Custom function to create a socket.
  * Must accept (port, host) and return a node-like socket.
@@ -1292,9 +1290,6 @@ Pool.prototype.handleAddr = co(function* handleAddr(peer, packet) {
 
     peer.addrFilter.add(addr.hostname, 'ascii');
 
-    if (this.options.noDiscovery)
-      continue;
-
     if (!addr.isRoutable())
       continue;
 
@@ -2014,7 +2009,7 @@ Pool.prototype.resolveChain = co(function* resolveChain(peer, hash) {
  */
 
 Pool.prototype.logStatus = function logStatus(block) {
-  if (this.logger.level >= 4 && this.chain.total % 20 === 0) {
+  if (this.chain.total % 20 === 0) {
     this.logger.debug('Status:'
       + ' ts=%s height=%d progress=%s'
       + ' blocks=%d orphans=%d active=%d'
@@ -3194,7 +3189,6 @@ function PoolOptions(options) {
   this.banScore = common.BAN_SCORE;
   this.banTime = common.BAN_TIME;
   this.feeRate = -1;
-  this.noDiscovery = false;
   this.seeds = this.network.seeds;
   this.nodes = [];
   this.invTimeout = 60000;
@@ -3394,11 +3388,6 @@ PoolOptions.prototype.fromOptions = function fromOptions(options) {
     this.feeRate = this.options.feeRate;
   }
 
-  if (options.noDiscovery != null) {
-    assert(typeof options.noDiscovery === 'boolean');
-    this.noDiscovery = options.noDiscovery;
-  }
-
   if (options.seeds) {
     assert(Array.isArray(options.seeds));
     this.seeds = options.seeds;
diff --git a/lib/node/config.js b/lib/node/config.js
index a43d2b31..96c08dd9 100644
--- a/lib/node/config.js
+++ b/lib/node/config.js
@@ -198,7 +198,6 @@ config.parseData = function parseData(data, prefix, dirname) {
   options.nodes = list(data.nodes);
   options.maxOutbound = num(data.maxoutbound);
   options.maxInbound = num(data.maxinbound);
-  options.noDiscovery = bool(data.nodiscovery);
   options.publicHost = str(data.publichost);
   options.publicPort = num(data.publicport);
   options.host = str(data.host);
diff --git a/lib/node/fullnode.js b/lib/node/fullnode.js
index f15c7255..e4320185 100644
--- a/lib/node/fullnode.js
+++ b/lib/node/fullnode.js
@@ -114,7 +114,6 @@ function FullNode(options) {
     proxyServer: this.options.proxyServer,
     seeds: this.options.seeds,
     nodes: this.options.nodes,
-    noDiscovery: this.options.noDiscovery,
     publicHost: this.options.publicHost,
     publicPort: this.options.publicPort,
     host: this.options.host,
diff --git a/lib/node/spvnode.js b/lib/node/spvnode.js
index a896ad13..0f1b7fc5 100644
--- a/lib/node/spvnode.js
+++ b/lib/node/spvnode.js
@@ -71,7 +71,6 @@ function SPVNode(options) {
     knownPeers: this.options.knownPeers,
     identityKey: this.options.identityKey,
     maxOutbound: this.options.maxOutbound,
-    noDiscovery: this.options.noDiscovery,
     headers: this.options.headers,
     selfish: true,
     listen: false