There might be a little confuse when I boot a local node and unknown nodes added to my init config

[yyuze]

System information

Geth version: geth version 1.14.11-stable-f3c696fa
CL client & version: none
OS & Version: Linux
Commit hash : f3c696f

I'm try building a local ethereum node, and I noticed there are sometimes unknown nodes appear at output of terminal command

admin.peers()

To figure out why, I added log at p2p/enode/node.go:81, (at the end of function newNodeWithID)

fmt.Printf("[YYUZE] new node: %+v\n", n);

Then when I use init command:

geth init --datadir ${PATH_TO_DATADIR} ${PATH_TO_GENESIS}

I got the following output:

[YYUZE] new node: enode://d860a01f9722d78051619d1e2351aba3f43f943f6f00718d1b9baa4101932a1f5011f16bb2b1bb35db20d6fe28fa0bf09636d26a87d31de9ec6203eeedb1f666@18.138.108.67:30303
[YYUZE] new node: enode://22a8232c3abc76a16ae9d6c3b164f98775fe226f0917b0ca871128a74a8e9630b458460865bab457221f1d448dd9791d24c4e5d88786180ac185df813a68d4de@3.209.45.79:30303
[YYUZE] new node: enode://2b252ab6a1d0f971d9722cb839a42cb81db019ba44c08754628ab4a823487071b5695317c8ccd085219c3a03af063495b2f1da8d18218da2d6a82981b45e6ffc@65.108.70.101:30303
[YYUZE] new node: enode://4aeb4ab6c14b23e2c4cfdce879c04b0748a20d8e9b59e25ded2a08143e265c6c25936e74cbc8e641e3312ca288673d91f2f93f8e277de3cfa444ecdaaf982052@157.90.35.166:30303
[YYUZE] new node: enr:-KG4QMOEswP62yzDjSwWS4YEjtTZ5PO6r65CPqYBkgTTkrpaedQ8uEUo1uMALtJIvb2w_WWEVmg5yt1UAuK1ftxUU7QDhGV0aDKQu6TalgMAAAD__________4JpZIJ2NIJpcIQEnfA2iXNlY3AyNTZrMaEDfol8oLr6XJ7FsdAYE7lpJhKMls4G_v6qQOGKJUWGb_uDdGNwgiMog3VkcIIjKA
[YYUZE] new node: enr:-KG4QF4B5WrlFcRhUU6dZETwY5ZzAXnA0vGC__L1Kdw602nDZwXSTs5RFXFIFUnbQJmhNGVU6OIX7KVrCSTODsz1tK4DhGV0aDKQu6TalgMAAAD__________4JpZIJ2NIJpcIQExNYEiXNlY3AyNTZrMaECQmM9vp7KhaXhI-nqL_R0ovULLCFSFTa9CPPSdb1zPX6DdGNwgiMog3VkcIIjKA
[YYUZE] new node: enr:-Ku4QImhMc1z8yCiNJ1TyUxdcfNucje3BGwEHzodEZUan8PherEo4sF7pPHPSIB1NNuSg5fZy7qFsjmUKs2ea1Whi0EBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpD1pf1CAAAAAP__________gmlkgnY0gmlwhBLf22SJc2VjcDI1NmsxoQOVphkDqal4QzPMksc5wnpuC3gvSC8AfbFOnZY_On34wIN1ZHCCIyg                  
[YYUZE] new node: enr:-Ku4QP2xDnEtUXIjzJ_DhlCRN9SN99RYQPJL92TMlSv7U5C1YnYLjwOQHgZIUXw6c-BvRg2Yc2QsZxxoS_pPRVe0yK8Bh2F0dG5ldHOIAAAAAAAAAACEZXRoMpD1pf1CAAAAAP__________gmlkgnY0gmlwhBLf22SJc2VjcDI1NmsxoQMeFF5GrS7UZpAH2Ly84aLK-TyvH-dRo0JM1i8yygH50YN1ZHCCJxA                  
[YYUZE] new node: enr:-Ku4QPp9z1W4tAO8Ber_NQierYaOStqhDqQdOPY3bB3jDgkjcbk6YrEnVYIiCBbTxuar3CzS528d2iE7TdJsrL-dEKoBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpD1pf1CAAAAAP__________gmlkgnY0gmlwhBLf22SJc2VjcDI1NmsxoQMw5fqqkw2hHC4F5HZZDPsNmPdB1Gi8JPQK7pRc9XHh-oN1ZHCCKvg
[YYUZE] new node: enr:-Le4QPUXJS2BTORXxyx2Ia-9ae4YqA_JWX3ssj4E_J-3z1A-HmFGrU8BpvpqhNabayXeOZ2Nq_sbeDgtzMJpLLnXFgAChGV0aDKQtTA_KgEAAAAAIgEAAAAAAIJpZIJ2NIJpcISsaa0Zg2lwNpAkAIkHAAAAAPA8kv_-awoTiXNlY3AyNTZrMaEDHAD2JKYevx89W0CcFJFiskdcEzkH_Wdv9iW42qLK79ODdWRwgiMohHVkcDaCI4I
[YYUZE] new node: enr:-Le4QLHZDSvkLfqgEo8IWGG96h6mxwe_PsggC20CL3neLBjfXLGAQFOPSltZ7oP6ol54OvaNqO02Rnvb8YmDR274uq8ChGV0aDKQtTA_KgEAAAAAIgEAAAAAAIJpZIJ2NIJpcISLosQxg2lwNpAqAX4AAAAAAPA8kv_-ax65iXNlY3AyNTZrMaEDBJj7_dLFACaxBfaI8KZTh_SSJUjhyAyfshimvSqo22WDdWRwgiMohHVkcDaCI4I
[YYUZE] new node: enr:-Le4QH6LQrusDbAHPjU_HcKOuMeXfdEB5NJyXgHWFadfHgiySqeDyusQMvfphdYWOzuSZO9Uq2AMRJR5O4ip7OvVma8BhGV0aDKQtTA_KgEAAAAAIgEAAAAAAIJpZIJ2NIJpcISLY9ncg2lwNpAkAh8AgQIBAAAAAAAAAAmXiXNlY3AyNTZrMaECDYCZTZEksF-kmgPholqgVt8IXr-8L7Nu7YrZ7HUpgxmDdWRwgiMohHVkcDaCI4I
[YYUZE] new node: enr:-Le4QIqLuWybHNONr933Lk0dcMmAB5WgvGKRyDihy1wHDIVlNuuztX62W51voT4I8qD34GcTEOTmag1bcdZ_8aaT4NUBhGV0aDKQtTA_KgEAAAAAIgEAAAAAAIJpZIJ2NIJpcISLY04ng2lwNpAkAh8AgAIBAAAAAAAAAA-fiXNlY3AyNTZrMaEDscnRV6n1m-D9ID5UsURk0jsoKNXt1TIrj8uKOGW6iluDdWRwgiMohHVkcDaCI4I
[YYUZE] new node: enr:-Ku4QHqVeJ8PPICcWk1vSn_XcSkjOkNiTg6Fmii5j6vUQgvzMc9L1goFnLKgXqBJspJjIsB91LTOleFmyWWrFVATGngBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpC1MD8qAAAAAP__________gmlkgnY0gmlwhAMRHkWJc2VjcDI1NmsxoQKLVXFOhp2uX6jeT0DvvDpPcU8FWMjQdR4wMuORMhpX24N1ZHCCIyg
[YYUZE] new node: enr:-Ku4QG-2_Md3sZIAUebGYT6g0SMskIml77l6yR-M_JXc-UdNHCmHQeOiMLbylPejyJsdAPsTHJyjJB2sYGDLe0dn8uYBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpC1MD8qAAAAAP__________gmlkgnY0gmlwhBLY-NyJc2VjcDI1NmsxoQORcM6e19T1T9gi7jxEZjk_sjVLGFscUNqAY9obgZaxbIN1ZHCCIyg
[YYUZE] new node: enr:-Ku4QPn5eVhcoF1opaFEvg1b6JNFD2rqVkHQ8HApOKK61OIcIXD127bKWgAtbwI7pnxx6cDyk_nI88TrZKQaGMZj0q0Bh2F0dG5ldHOIAAAAAAAAAACEZXRoMpC1MD8qAAAAAP__________gmlkgnY0gmlwhDayLMaJc2VjcDI1NmsxoQK2sBOLGcUb4AwuYzFuAVCaNHA-dy24UuEKkeFNgCVCsIN1ZHCCIyg
[YYUZE] new node: enr:-Ku4QEWzdnVtXc2Q0ZVigfCGggOVB2Vc1ZCPEc6j21NIFLODSJbvNaef1g4PxhPwl_3kax86YPheFUSLXPRs98vvYsoBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpC1MD8qAAAAAP__________gmlkgnY0gmlwhDZBrP2Jc2VjcDI1NmsxoQM6jr8Rb1ktLEsVcKAPa08wCsKUmvoQ8khiOl_SLozf9IN1ZHCCIyg
[YYUZE] new node: enr:-LK4QA8FfhaAjlb_BXsXxSfiysR7R52Nhi9JBt4F8SPssu8hdE1BXQQEtVDC3qStCW60LSO7hEsVHv5zm8_6Vnjhcn0Bh2F0dG5ldHOIAAAAAAAAAACEZXRoMpC1MD8qAAAAAP__________gmlkgnY0gmlwhAN4aBKJc2VjcDI1NmsxoQJerDhsJ-KxZ8sHySMOCmTO6sHM3iCFQ6VMvLTe948MyYN0Y3CCI4yDdWRwgiOM
[YYUZE] new node: enr:-LK4QKWrXTpV9T78hNG6s8AM6IO4XH9kFT91uZtFg1GcsJ6dKovDOr1jtAAFPnS2lvNltkOGA9k29BUN7lFh_sjuc9QBh2F0dG5ldHOIAAAAAAAAAACEZXRoMpC1MD8qAAAAAP__________gmlkgnY0gmlwhANAdd-Jc2VjcDI1NmsxoQLQa6ai7y9PMN5hpLe5HmiJSlYzMuzP7ZhwRiwHvqNXdoN0Y3CCI4yDdWRwgiOM

I checked the code, and find that's because default nodes are added to cfg.BootstrapNodes at cmd/utils/flags.go:1035

1034 func setBootstrapNodes(ctx *cli.Context, cfg *p2p.Config) {                                                              
1035     urls := params.MainnetBootnodes                                                                                      
1036     if ctx.IsSet(BootnodesFlag.Name) {                                                                                   
1037         urls = SplitAndTrim(ctx.String(BootnodesFlag.Name))                                                              
1038     } else {                                                                                                             
1039         if cfg.BootstrapNodes != nil {                                                                                   
1040             return // Already set by config file, don't apply defaults.                                                  
1041         }                                                                                                                
1042         switch {                                                                                                         
1043         case ctx.Bool(HoleskyFlag.Name):                                                                                 
1044             urls = params.HoleskyBootnodes                                                                               
1045         case ctx.Bool(SepoliaFlag.Name):                                                                                 
1046             urls = params.SepoliaBootnodes                                                                               
1047         }                                                                                                                
1048     }                                                                                                                    
1049     cfg.BootstrapNodes = mustParseBootnodes(urls)                                                                                                                                                                                                                         
1050 }

Expected behaviour

Maybe it's better that default urls is empty when configuring a totally new blockchain instead of adding some default nodes of mainnet?

Actual behaviour

no default nodes from mainnet

Steps to reproduce the behaviour

genesis.json:

{                                                                                                                           
  "config": {                                                                                                               
    "chainId"                           : 113,                                                                              
    "homesteadBlock"                    : 0,                                                                                
    "eip150Block"                       : 0,                                                                                
    "eip155Block"                       : 0,                                                                                
    "eip158Block"                       : 0,                                                                                
    "byzantiumBlock"                    : 0,                                                                                
    "constantinopleBlock"               : 0,                                                                                
    "petersburgBlock"                   : 0,                                                                                
    "istanbulBlock"                     : 0,                                                                                
    "berlinBlock"                       : 0,                                                                                
    "londonBlock"                       : 0,                                                                                
    "ethash"                            : {},                                                                               
    "terminalTotalDifficultyPassed"     : true                                                                              
  },                                                                                                                        
  "alloc": {                                                                                                                
    "0x0000000000000000000000000000000000000001": {                                                                         
      "balance": "111111111"                                                                                                
    },                                                                                                                      
    "0x0000000000000000000000000000000000000002": {                                                                         
      "balance": "222222222"                                                                                                
    }                                                                                                                       
  },                                                                                                                        
  "coinbase"                            : "0x0000000000000000000000000000000000000000",                                     
  "difficulty"                          : "0x20000",                                                                        
  "extraData"                           : "",                                                                               
  "gasLimit"                            : "0x2fefd8",                                                                       
  "nonce"                               : "0x0000000000000042",                                                             
  "mixhash"                             : "0x0000000000000000000000000000000000000000000000000000000000000000",                                                                                                                                                                
  "parentHash"                          : "0x0000000000000000000000000000000000000000000000000000000000000000",             
  "timestamp"                           : "0x00"                                                                            
}

reproduce command

geth init genesis.json

Backtrace

none

[yyuze]

beside, geth init is not support option '--bootnodes' or '--config', hence there is no way to make params.MainnetBootnodes be overrided by user-defined nodes

[fjl]

The bootstrap nodes are not a part of the genesis configuration. They are just a node configuration setting.
Please note that discovery nodes and peers are not the same thing. The discovery system is not tied to a particular blockchain and works across all chains.