Satoshi Client Node Discovery - Revision history

WikiR: Removed inactive DNS seed (seed.bitcoin.jonasschnelli.ch) due to lack of response - unreachable.

2025-02-22T13:37:44Z

Removed inactive DNS seed (seed.bitcoin.jonasschnelli.ch) due to lack of response - unreachable.

← Older revision		Revision as of 13:37, 22 February 2025
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	* dnsseed.bitcoin.dashjr.org		* dnsseed.bitcoin.dashjr.org
	* seed.bitcoinstats.com		* seed.bitcoinstats.com
	* seed.bitcoin.jonasschnelli.ch
	* seed.btc.petertodd.org		* seed.btc.petertodd.org

JonathanCross: /* DNS Addresses */ Updating line number for seed nodes and month to now.

2017-12-19T02:29:15Z

DNS Addresses: Updating line number for seed nodes and month to now.

← Older revision		Revision as of 02:29, 19 December 2017
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	===DNS Addresses===		===DNS Addresses===
	Upon startup, if peer node discovery is needed, the client then issues DNS requests to learn about the addresses of other peer nodes. The client includes a list of host names for DNS services that are seeded. As of ~~November~~, 2017 the list (from chainparams.cpp<ref>[https://github.com/bitcoin/bitcoin/blob/master/src/chainparams.cpp#~~L139~~ bitcoin/src/chainparams.cpp at master]</ref>) includes:		Upon startup, if peer node discovery is needed, the client then issues DNS requests to learn about the addresses of other peer nodes. The client includes a list of host names for DNS services that are seeded. As of December, 2017 the list (from chainparams.cpp<ref>[https://github.com/bitcoin/bitcoin/blob/master/src/chainparams.cpp#L128 bitcoin/src/chainparams.cpp at master]</ref>) includes:

	* seed.bitcoin.sipa.be		* seed.bitcoin.sipa.be

Eklitzke: update dns seed list

2017-11-22T00:15:42Z

update dns seed list

← Older revision		Revision as of 00:15, 22 November 2017
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	===DNS Addresses===		===DNS Addresses===
	Upon startup, if peer node discovery is needed, the client then issues DNS requests to learn about the addresses of other peer nodes. The client includes a list of host names for DNS services that are seeded. As-of ~~May 17~~, ~~2012~~ the list (from chainparams.cpp<ref>[https://github.com/bitcoin/bitcoin/blob/master/src/chainparams.cpp#L139 bitcoin/src/chainparams.cpp at master]</ref>) includes:		Upon startup, if peer node discovery is needed, the client then issues DNS requests to learn about the addresses of other peer nodes. The client includes a list of host names for DNS services that are seeded. As of November, 2017 the list (from chainparams.cpp<ref>[https://github.com/bitcoin/bitcoin/blob/master/src/chainparams.cpp#L139 bitcoin/src/chainparams.cpp at master]</ref>) includes:

	* ~~bitseed~~.~~xf2~~.~~org~~		* seed.bitcoin.sipa.be
	* dnsseed.bluematt.me		* dnsseed.bluematt.me
	* seed.bitcoin.sipa.be
	* dnsseed.bitcoin.dashjr.org		* dnsseed.bitcoin.dashjr.org
	* seed.bitcoinstats.com		* seed.bitcoinstats.com
			* seed.bitcoin.jonasschnelli.ch
			* seed.btc.petertodd.org

	A DNS reply can contain multiple IP addresses for a requested name.		A DNS reply can contain multiple IP addresses for a requested name.

Cdecker: /* DNS Addresses */ Added bitcoinstats.com DNS seed as of Version 0.9 of Bitcoin

2014-03-13T12:24:15Z

DNS Addresses: Added bitcoinstats.com DNS seed as of Version 0.9 of Bitcoin

← Older revision		Revision as of 12:24, 13 March 2014
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	* seed.bitcoin.sipa.be		* seed.bitcoin.sipa.be
	* dnsseed.bitcoin.dashjr.org		* dnsseed.bitcoin.dashjr.org
			* seed.bitcoinstats.com

	A DNS reply can contain multiple IP addresses for a requested name.		A DNS reply can contain multiple IP addresses for a requested name.

Wyager: /* Address Relay */

2013-07-04T00:03:00Z

Address Relay

← Older revision		Revision as of 00:03, 4 July 2013
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	#The address must be routable.		#The address must be routable.

	For every address that meets the above criteria, the node hash the address, the current day (in the form of an integer), and a random 256 bit value (generated at client startup). The node takes the two addresses with the lowest hash values and relays "addr" messages to them. This ensures that each node only relays "addr" messages to two other clients, that the two other clients are randomly selected, and that the random selection starts over at least once every 24 hours.		For every address that meets the above criteria, the node hash the address, the current day (in the form of an integer), and a random 256 bit value (generated at client startup). The node takes the two addresses with the lowest hash values and relays "addr" messages to them. This ensures that each node only relays "addr" messages to two other clients at any given time, that the two other clients are randomly selected, and that the random selection starts over at least once every 24 hours.

	====Self broadcast====		====Self broadcast====

Wyager at 00:02, 4 July 2013

2013-07-04T00:02:16Z

← Older revision		Revision as of 00:02, 4 July 2013
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	#The address must be routable.		#The address must be routable.

	~~When they meet~~ the above criteria, the node ~~hashes all~~ the ~~eligible node IP addresses~~, ~~as well as~~ the current day in the form of an integer, and the two ~~nodes~~ with the lowest hash ~~value~~ are ~~chosen to have~~ the ~~address relayed to them~~.		For every address that meets the above criteria, the node hash the address, the current day (in the form of an integer), and a random 256 bit value (generated at client startup). The node takes the two addresses with the lowest hash values and relays "addr" messages to them. This ensures that each node only relays "addr" messages to two other clients, that the two other clients are randomly selected, and that the random selection starts over at least once every 24 hours.

	====Self broadcast====		====Self broadcast====

Michagogo: Modernized somewhat

2013-07-03T21:54:29Z

Modernized somewhat

← Older revision		Revision as of 21:54, 3 July 2013
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	# Nodes discover their own external address by various methods.		# Nodes discover their own external address by various methods.
	# Nodes receive the callback address of remote nodes that connect to them.		# Nodes receive the callback address of remote nodes that connect to them.
	~~# Nodes connect to IRC to receive addresses.~~
	# Nodes makes DNS request to receive IP addresses.		# Nodes makes DNS request to receive IP addresses.
	# Nodes can use addresses hard coded into the software.		# Nodes can use addresses hard coded into the software.
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	===Local Client's External Address===		===Local Client's External Address===
	The client uses ~~two methods~~ to determine its own external, routable IP address~~: it uses IRC, preferably, and if that does not succeed, it uses public web services which return the information~~.		The client uses public web services which return the information to determine its own external, routable IP address.

	From a thread created for this work (called ThreadIRCSeed in [https://github.com/bitcoin/bitcoin/blob/master/src/irc.cpp irc.cpp]), the client makes an IRC connection to 92.243.23.21 or irc.lfnet.org, if the direct IP connection fails. The port is 6667.		The client runs a thread called ThreadGetMyExternalIP (in [https://github.com/bitcoin/bitcoin/blob/master/src/net.cpp net.cpp])

	~~If the connection succeeds, the client issues a USERHOST command to the IRC server, in order to get their own IP address.~~

	The client ~~also~~ runs a thread called ThreadGetMyExternalIP (in [https://github.com/bitcoin/bitcoin/blob/master/src/net.cpp net.cpp])
	which attempts to determine the client's IP address as seen from the outside		which attempts to determine the client's IP address as seen from the outside
	world~~. It gives the IRC thread a chance to discover the IP address~~		world.
	~~first, sleeping and checking periodically for 2 minutes, and then it~~
	~~proceeds if the IRC method did not succeed~~.

	First, it attempts to connect to 91.198.22.70 port 80, which should be		First, it attempts to connect to 91.198.22.70 port 80, which should be
	the checkip.dyndns.org server. If connection fails, a DNS request is made		the checkip.dyndns.org server. If connection fails, a DNS request is made
	for checkip.dyndns.org and a connection is attempted to that address.		for checkip.dyndns.org and a connection is attempted to that address.
	Next, it ~~attemps~~ to connect to 74.208.43.192 port 80, which should be		Next, it attempts to connect to 74.208.43.192 port 80, which should be
	the www.showmyip.com server. If connection fails, a DNS request is made		the www.showmyip.com server. If connection fails, a DNS request is made
	for www.showmyip.com and a connection is attempted to that address.		for www.showmyip.com and a connection is attempted to that address.
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	send a HTTP request, read the appropriate response line, and parse the		send a HTTP request, read the appropriate response line, and parse the
	IP address from it.		IP address from it.
	If this succeeds, the IP is returned, it is advertised to any connected		If this succeeds, the IP address is returned, it is advertised to any connected
	nodes, and then the thread finishes (without proceeding to the next		nodes, and then the thread finishes (without proceeding to the next
	address).		address).
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	===IRC Addresses===		===IRC Addresses===

	As of version 0.6.x the Bitcoin client no longer uses IRC bootstrapping by default. This documentation below is accurate for most prior versions.		As of version 0.6.x the Bitcoin client no longer uses IRC bootstrapping by default, and as of version 0.8.2 support for IRC bootstrapping has been removed completely. This documentation below is accurate for most prior versions.

	In addition to learning and sharing its own address, the node ~~learns~~ about other node addresses via an IRC channel. See [https://github.com/bitcoin/bitcoin/blob/~~master~~/src/irc.cpp irc.cpp].		In addition to learning and sharing its own address, the node learned about other node addresses via an IRC channel. See [https://github.com/bitcoin/bitcoin/blob/847593228de8634bf6ef5933a474c7e63be59146/src/irc.cpp irc.cpp].

	After learning its own address, a node ~~encodes~~ its own address into a string to be used as a nickname. Then, it randomly ~~joins~~ an IRC channel named between #bitcoin00 and #bitcoin99. Then it ~~issues~~ a WHO command. The thread ~~reads~~ the lines as they ~~appear~~ in the channel and ~~decodes~~ the IP addresses of other nodes in the channel. It ~~does~~ this in a loop, forever, until the node is shutdown.		After learning its own address, a node encoded its own address into a string to be used as a nickname. Then, it randomly joined an IRC channel named between #bitcoin00 and #bitcoin99. Then it issued a WHO command. The thread read the lines as they appeared in the channel and decoded the IP addresses of other nodes in the channel. It did this in a loop, forever, until the node was shutdown.

	When the client ~~discovers~~ an address from IRC, it ~~sets~~ the timestamp on the address to the current time, but it ~~uses~~ a "penalty" of 51 minutes, which means it ~~looks~~ like it was actually seen almost an hour ~~ago~~.		When the client discovered an address from IRC, it set the timestamp on the address to the current time, but it used a "penalty" of 51 minutes, which means it looked like it was actually seen almost an hour earlier.

	===DNS Addresses===		===DNS Addresses===
	Upon startup, if peer node discovery is needed, the client then issues DNS requests to learn about the addresses of other peer nodes. The client includes a list of host names for DNS services that are seeded. As-of May 17, 2012 the list (from ~~net~~.cpp<ref>[https://github.com/bitcoin/bitcoin/blob/master/src/~~net~~.cpp bitcoin/src/~~net~~.cpp at master]</ref>) includes:		Upon startup, if peer node discovery is needed, the client then issues DNS requests to learn about the addresses of other peer nodes. The client includes a list of host names for DNS services that are seeded. As-of May 17, 2012 the list (from chainparams.cpp<ref>[https://github.com/bitcoin/bitcoin/blob/master/src/chainparams.cpp#L139 bitcoin/src/chainparams.cpp at master]</ref>) includes:

	* bitseed.xf2.org		* bitseed.xf2.org

An0nymous: /* IRC Addresses */

2013-01-18T04:41:10Z

IRC Addresses

← Older revision		Revision as of 04:41, 18 January 2013
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	As of version 0.6.x the Bitcoin client no longer uses IRC bootstrapping by default. This documentation below is accurate for most prior versions.		As of version 0.6.x the Bitcoin client no longer uses IRC bootstrapping by default. This documentation below is accurate for most prior versions.

	In addition to learning and sharing its own address, the node learns about other node addresses via an IRC channel. See irc.cpp.		In addition to learning and sharing its own address, the node learns about other node addresses via an IRC channel. See [https://github.com/bitcoin/bitcoin/blob/master/src/irc.cpp irc.cpp].

	After learning its own address, a node encodes its own address into a string to be used as a nickname. Then, it randomly joins an IRC channel named between #bitcoin00 and #bitcoin99. Then it issues a WHO command. The thread reads the lines as they appear in the channel and decodes the IP addresses of other nodes in the channel. It does this in a loop, forever, until the node is shutdown.		After learning its own address, a node encodes its own address into a string to be used as a nickname. Then, it randomly joins an IRC channel named between #bitcoin00 and #bitcoin99. Then it issues a WHO command. The thread reads the lines as they appear in the channel and decodes the IP addresses of other nodes in the channel. It does this in a loop, forever, until the node is shutdown.

An0nymous: /* Local Client's External Address */

2013-01-18T04:40:11Z

Local Client's External Address

← Older revision		Revision as of 04:40, 18 January 2013
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	The client uses two methods to determine its own external, routable IP address: it uses IRC, preferably, and if that does not succeed, it uses public web services which return the information.		The client uses two methods to determine its own external, routable IP address: it uses IRC, preferably, and if that does not succeed, it uses public web services which return the information.

	From a thread created for this work (called ThreadIRCSeed in irc.cpp), the client makes an IRC connection to 92.243.23.21 or irc.lfnet.org, if the direct IP connection fails. The port is 6667.		From a thread created for this work (called ThreadIRCSeed in [https://github.com/bitcoin/bitcoin/blob/master/src/irc.cpp irc.cpp]), the client makes an IRC connection to 92.243.23.21 or irc.lfnet.org, if the direct IP connection fails. The port is 6667.

	If the connection succeeds, the client issues a USERHOST command to the IRC server, in order to get their own IP address.		If the connection succeeds, the client issues a USERHOST command to the IRC server, in order to get their own IP address.

	The client also runs a thread called ThreadGetMyExternalIP (in net.cpp)		The client also runs a thread called ThreadGetMyExternalIP (in [https://github.com/bitcoin/bitcoin/blob/master/src/net.cpp net.cpp])
	which attempts to determine the client's IP address as seen from the outside		which attempts to determine the client's IP address as seen from the outside
	world. It gives the IRC thread a chance to discover the IP address		world. It gives the IRC thread a chance to discover the IP address
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	nodes, and then the thread finishes (without proceeding to the next		nodes, and then the thread finishes (without proceeding to the next
	address).		address).


	===Connect Callback Address===		===Connect Callback Address===

An0nymous: /* Overview */

2013-01-18T04:39:08Z

Overview

← Older revision		Revision as of 04:39, 18 January 2013
Line 14:		Line 14:

	A timestamp is kept for each address to keep track of when the node		A timestamp is kept for each address to keep track of when the node
	address was last seen. The AddressCurrentlyConnected in net.cpp handles		address was last seen. The AddressCurrentlyConnected in [https://github.com/bitcoin/bitcoin/blob/master/src/net.cpp net.cpp] handles
	updating the timestamp whenever a message is received from a node.		updating the timestamp whenever a message is received from a node.
	Timestamps are only updated on an address and saved to the database		Timestamps are only updated on an address and saved to the database
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	timestamps, it will become more clear why timestamps are kept the way		timestamps, it will become more clear why timestamps are kept the way
	they are for each of the different ways an address is discovered.		they are for each of the different ways an address is discovered.


	==Handling Message "getaddr"==		==Handling Message "getaddr"==