diff --git a/src/net.cpp b/src/net.cpp index 34dc67eb4..1bca168d1 100644 --- a/src/net.cpp +++ b/src/net.cpp @@ -1463,12 +1463,19 @@ static std::string GetDNSHost(const CDNSSeedData& data, ServiceFlags* requiredSe void CConnman::ThreadDNSAddressSeed() { // goal: only query DNS seeds if address need is acute + // Avoiding DNS seeds when we don't need them improves user privacy by + // creating fewer identifying DNS requests, reduces trust by giving seeds + // less influence on the network topology, and reduces traffic to the seeds. if ((addrman.size() > 0) && (!GetBoolArg("-forcednsseed", DEFAULT_FORCEDNSSEED))) { MilliSleep(11 * 1000); LOCK(cs_vNodes); - if (vNodes.size() >= 2) { + int nRelevant = 0; + for (auto pnode : vNodes) { + nRelevant += pnode->fSuccessfullyConnected && ((pnode->nServices & nRelevantServices) == nRelevantServices); + } + if (nRelevant >= 2) { LogPrintf("P2P peers available. Skipped DNS seeding.\n"); return; } @@ -1675,8 +1682,8 @@ void CConnman::ThreadOpenConnections() if (nANow - addr.nLastTry < 600 && nTries < 30) continue; - // only consider nodes missing relevant services after 40 failed attempts - if ((addr.nServices & nRelevantServices) != nRelevantServices && nTries < 40) + // only consider nodes missing relevant services after 40 failed attempts and only if less than half the outbound are up. + if ((addr.nServices & nRelevantServices) != nRelevantServices && (nTries < 40 || nOutbound >= (nMaxOutbound >> 1))) continue; // do not allow non-default ports, unless after 50 invalid addresses selected already