From 03c58fc08aa0f08f37b79009049911545c285cf6 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Tue, 14 May 2019 12:16:19 -0400
Subject: [PATCH] p2p/discover: reject older records in requestENR

---
 p2p/discover/v4_udp.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/p2p/discover/v4_udp.go b/p2p/discover/v4_udp.go
index 314b497db2..8937c07b09 100644
--- a/p2p/discover/v4_udp.go
+++ b/p2p/discover/v4_udp.go
@@ -551,6 +551,9 @@ func (t *UDPv4) requestENR(n *enode.Node) (*enode.Node, error) {
 	if respN.ID() != n.ID() {
 		return nil, fmt.Errorf("invalid ID in response record")
 	}
+	if respN.Seq() < n.Seq() {
+		return n, nil // response record is older
+	}
 	if err := netutil.CheckRelayIP(addr.IP, respN.IP()); err != nil {
 		return nil, fmt.Errorf("invalid IP in response record: %v", err)
 	}