From 44e3365d4fa2db501e846bfce662bdf8b20fb808 Mon Sep 17 00:00:00 2001
From: JackDoan <me@jackdoan.com>
Date: Tue, 20 Oct 2026 15:47:43 -0500
Subject: [PATCH] Size send failure heads from the header length and tolerate a
 missing lighthouse

---
 hostmap.go                | 2 +-
 overlay/batch/tx_batch.go | 8 ++++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/hostmap.go b/hostmap.go
index 49fecb5e..6dd29807 100644
--- a/hostmap.go
+++ b/hostmap.go
@@ -783,7 +783,7 @@ func (i *HostInfo) remoteUnreachable(ifce *Interface, dead netip.AddrPort) {
 		// Nothing to probe with, or we already moved on from the remote that failed
 		return
 	}
-	if ifce.lightHouse.amLighthouse {
+	if ifce.lightHouse == nil || ifce.lightHouse.amLighthouse {
 		// A lighthouse hands out the address it reaches a client on, it must not go roaming its clients itself
 		return
 	}
diff --git a/overlay/batch/tx_batch.go b/overlay/batch/tx_batch.go
index 14a58ba4..5984997c 100644
--- a/overlay/batch/tx_batch.go
+++ b/overlay/batch/tx_batch.go
@@ -1,11 +1,15 @@
 package batch
 
-import "net/netip"
+import (
+	"net/netip"
+
+	"github.com/slackhq/nebula/header"
+)
 
 const SendBatchCap = 128
 
 // FailureHeadLen is how much of a refused packet a Failure keeps, nebula's header, which says whose packet it was
-const FailureHeadLen = 16
+const FailureHeadLen = header.Len
 
 // batchWriter is the minimal subset of udp.Conn needed by SendBatch to flush.
 type batchWriter interface {