How Nodes Find Each Other

Ethereum Classic (ETC) network nodes have accurate information about the network in spite of it being decentralized and constantly changing. I will describe how this happens.

Some network nodes are always available and accepting of new connections from other network nodes. These are referred to as bootstrap nodes. New network nodes first connect to bootstrap nodes to obtain information. Here is the current Geth bootstrap node list with network nodes specified using “enode” strings:

enode://e809c4a2fec7daed400e5e28564e23693b23b2cc5a019b612505631bbe7b9ccf709c1796d2a3d29ef2b045f210caf51e3c4f5b6d3587d43ad5d6397526fa6179@174.112.32.157:30303
enode://6e538e7c1280f0a31ff08b382db5302480f775480b8e68f8febca0ceff81e4b19153c6f8bf60313b93bef2cc34d34e1df41317de0ce613a201d1660a788a03e2@52.206.67.235:30303
enode://5fbfb426fbb46f8b8c1bd3dd140f5b511da558cd37d60844b525909ab82e13a25ee722293c829e52cb65c2305b1637fa9a2ea4d6634a224d5f400bfe244ac0de@162.243.55.45:30303
enode://42d8f29d1db5f4b2947cd5c3d76c6d0d3697e6b9b3430c3d41e46b4bb77655433aeedc25d4b4ea9d8214b6a43008ba67199374a9b53633301bca0cd20c6928ab@104.155.176.151:30303
enode://814920f1ec9510aa9ea1c8f79d8b6e6a462045f09caa2ae4055b0f34f7416fca6facd3dd45f1cf1673c0209e0503f02776b8ff94020e98b6679a0dc561b4eba0@104.154.136.117:30303
enode://72e445f4e89c0f476d404bc40478b0df83a5b500d2d2e850e08eb1af0cd464ab86db6160d0fde64bd77d5f0d33507ae19035671b3c74fec126d6e28787669740@104.198.71.200:30303
enode://5cd218959f8263bc3721d7789070806b0adff1a0ed3f95ec886fb469f9362c7507e3b32b256550b9a7964a23a938e8d42d45a0c34b332bfebc54b29081e83b93@35.187.57.94:30303
enode://39abab9d2a41f53298c0c9dc6bbca57b0840c3ba9dccf42aa27316addc1b7e56ade32a0a9f7f52d6c5db4fe74d8824bcedfeaecf1a4e533cacb71cf8100a9442@144.76.238.49:30303
enode://f50e675a34f471af2438b921914b5f06499c7438f3146f6b8936f1faeb50b8a91d0d0c24fb05a66f05865cd58c24da3e664d0def806172ddd0d4c5bdbf37747e@144.76.238.49:30306
enode://6dd3ac8147fa82e46837ec8c3223d69ac24bcdbab04b036a3705c14f3a02e968f7f1adfcdb002aacec2db46e625c04bf8b5a1f85bb2d40a479b3cc9d45a444af@104.237.131.102:30303

All enode strings contain Elliptic Curve Digital Signature Algorithm (ECDSA) public keys and internet sockets (addresses and ports).

Additional network nodes are found by network nodes storing and sharing lists of network nodes that have recently communicated with them. Ignoring older activity decreases the probability of sharing information about nonexistent network nodes. Network nodes continually communicate and thereby continually share their information. The whole process starts with bootstrap nodes and quickly includes many other network nodes.

Here is the current list for my Parity ETC node:

enode://9fe33f0ebc5b0ce51879afa3f767b2a180536dafb34b5af24cef11bb1c136b90d7839d6340d912ccd1f8e917a9e24d0d908ca4811a15889fcbf70733d7411608@122.215.240.147:30303
enode://e1520f00ff23e82c87411964a70c08e77592aab16647ddc2b53a5617808330184aaaac786002d31e40a1db6ec1447d6b0d8ebc7d9099cc90d606b7936fd9b908@172.86.120.213:30303
enode://a68a96163c842f1175d8eb515ca60ab93e80ab581cded1a11527f53e89f1f1cfb624e3f0a79a5dd76ee0fad54758ec9515be38158b2cf01635dcf444db6716db@46.101.169.110:30303
enode://e5ddf2ea2373697136681eaba314039ce60b99656c4eefabb2d01032d77dae384919941589f1d9309c340a854310b556d059521414db93c3b0d5ed5ff1308dc4@13.125.218.87:30303
enode://f5d269ebbfb94494e7e2251a49f430df5d7f510cf04173dad1229b12e4929e6a65f4c76cf9cb0f789c30f7a9d2e50a453a64bb0f797429fe3f2e30cbd0198c0b@35.230.160.215:30303
enode://efce38b6ee1baa4fa0a48c4202cc175fe4668a376365bbd0b9735a06de04593c822e9064d6664e346af5c98efc0dd0e4f3f1b8b64364aba5f2c51b259accc41c@47.98.232.156:30303
enode://c38fadc7d03341aaa856c41d8af9733d535cbbde3e3e103dd97c1bf6a0e15f8a6ed77c7bfb04784d9be7bdef884172a1fca8367f3750d4e3d0e9a0e95db57e29@47.97.72.201:30303
enode://10a0e3e2e4d9be6eab3615cd441da32dcebc7d51df9639c92eae35a7a434cf2c8e2bec756573ca9f49f48d6ed65917d4fbd220658d21888ee75799de955f2580@13.125.156.101:30303
enode://c1e0e9f8607afc20b70dc6f2b19258e879841561360385c63d004a9cdb1a93f1122e061ad405ff98a03f3413a945c9299e19d6bd6bc86a17682e34f811f12d32@52.57.166.35:30303
enode://f4a1153780ccb0b4e2c86bdf11837035f621ddc09bcf7d874a9879bc20adf5a32ce0b5cda91674873ad4cd89ca0b6da6a89197102922ea58d3f98ec421368240@167.114.236.10:30303
enode://7c253d4172cb27a7c514c35ee1cad1ff0fa1a6d2d2ca1c3a6f67d7416173bf0f36c64d6caf5f3cf13700e81104b10642787c17bbfb00e67d1a85c5a88c613cd6@13.125.206.176:30303
enode://ed81e7f825a5309c3c93698a440055f10fa617342f6e8c62645b3ee813515c488addee22a3175223b4d0bc410c0b3f0a2bc25d67ee2d75cfa4f8bac6006a8f6a@109.236.81.109:30307
enode://8d45cb061b744f444d38c58f2fd972214f565e24539eb5ccd85612290a66d9da885a1012576784ab2a2cb93050a4ef99e6ba0931963fe7ed4370def400349dbf@149.202.174.161:30303
enode://1275a4224ee8ee7cedc5ab62a118428f6f4ec2841440cefacf8d01c368ac345d687052c667204e52cc22f0b85de0fc8195aceee5d2d28d2c69d3a3644aecb840@115.22.91.166:30303
enode://c60ae3bccd9ccded51ad5e8c2aa6bad8fad072c1809779566c85ca17f2f5d810fd6c11761e892c45787e9f27a213cc9ade3244f7a8f8e9fb071e8281b263740e@61.100.182.189:40404
enode://feaf167dad6e117bc07c507b8cf4aa1978cdcc592d218bde7782c67abc53dbf02ea8aa6799946aee4f8e5f73c58dbc28eadaa8739431bc0233f78562c5266c24@13.125.25.106:30305
enode://ba8efe932cbf32f0d8ee9a0af45ade59dd26e81cafdc86497e57aca0ae5e9bcc64ee058a4c844bc0d06ceea2db062f377705870b14c72db2977f110485d809cf@5.9.6.244:30303
enode://c989f4ceea49188426561d2a1833c157cfd137948ae054ab47e770f4032b7708ac59121e13d0c267c23779b96cae258d39e4c05ac55b6a7300fbaa79dd19b541@52.30.37.160:30305
enode://4329eb2c7e62206421469d413ddc6f8bdf10eb176aaec065282bd31d198ace82871034fa4af34ad0ed5051d2d9d82845a6729f254220fffd91175cddb20318cd@167.114.236.167:30303
enode://485f2c2368cfb6614026058e37c4d1a63aba7285df77663198c96824dc9b44b2d3861198d42d8c00f7f2d3ee7a00619ebb6e2f70ee96cfd0ca13d7a98a438b52@52.221.229.254:30303
enode://78f960f4cc378980409704957818e55bb671775d3ca3f731fb8a0468a1156b7158a42e921f4077eaf9de3e8a6905360fca629dfbdb089b083aa0e46a0554ce09@159.65.3.132:30303
enode://5eb58e0bda31307b19b6d25350bba7b812fc0337cb34e79a5796bbdcaf3bace0535d56e2f485cab7839d03754d5bacb98d666c8c2e9a2ca3c8fe5a9e2b0f63a1@47.91.28.47:30305
enode://ad132e9609f8288c07e8958af5b1c77dad6001af774e5a5b3d3e06bd339b8a52e63a70ba92df917ddaa1494ed228c735cc5be00f4d59cffe995eb574eb467827@120.131.14.202:30303
enode://f926fb79061578191b8d125d6fca889f711c94d1dab19f3c106671812a098bb7837b5b40c67f8f0ae2bd0a0410cfa57a00270af8ebe7e9162e3f7b034df554eb@13.78.23.204:30303
enode://a38b8841524f4a0f6e4161511ef9ed60b7da1a5303a316fd99d997c5f2642313eab3cbe560b1c62dab1ac9be8e92fe61611c41728c3628b59d2a23ae731ea717@165.227.151.104:30303

Amazingly, ETC nodes can find each other within a headless and ever changing system. There are many such brilliant riches to appreciate in the ETC design when one looks.