only add one sample per bootstrap node

index.js

@@ -299,9 +299,9 @@ class DHT extends EventEmitter {
   async _onpersistent () {
     if (this.ephemeral === false) return false
 
-    // TODO: do nat check also
-
-    const addr = this.remoteAddress(this._forcePersistent ? 1 : 3)
+    // only require one sample here as we do the nat check anyway after
+    // makes settting up a dht easier...
+    const addr = this.remoteAddress(1)
 
     if (addr.type !== DHT.NAT_PORT_CONSISTENT && addr.type !== DHT.NAT_OPEN) {
       this._persistentTicks = MORE_PERSISTENT_TICKS
@@ -473,7 +473,7 @@ class DHT extends EventEmitter {
     }
 
     // add a sample of our address from the remote nodes pov
-    this._nat.add(m.to)
+    this._nat.add(m.to, m.from)
 
     this._addNode({
       id,
@@ -522,7 +522,7 @@ class DHT extends EventEmitter {
 
   _onresponse (res) {
     if (res.id !== null) this._addNodeFromMessage(res)
-    else if (this._nat.length < 3) this._nat.add(res.to)
+    else if (this._nat.length < 3 && !this._nat.sampled(res.from)) this._nat.add(res.to, res.from)
   }
 
   bind (...args) {

lib/nat-analyzer.js

@@ -9,9 +9,17 @@ class NatAnalyzer {
     this.top = 0
   }
 
-  add (addr) {
+  sampled (referrer) {
+    for (let i = 0; i < this.length; i++) {
+      const r = this.samples[i].referrer
+      if (r.port === referrer.port && r.host === referrer.host) return true
+    }
+    return false
+  }
+
+  add (addr, referrer) {
     if (this.length < this.samples.length) this.length++
-    this.samples[this.top] = { port: addr.port, host: addr.host, dist: 0 }
+    this.samples[this.top] = { port: addr.port, host: addr.host, dist: 0, referrer }
     this.top = (this.top + 1) & (this.samples.length - 1)
   }