From 37f26beb505fa28f5db317c4829c61ef1a4e5930 Mon Sep 17 00:00:00 2001
From: Travis LaDuke <travisladuke@gmail.com>
Date: Tue, 2 Nov 2021 11:15:10 -0700
Subject: [PATCH] Fix multicast flag on linux interfaces.

When we re-ordered the way the interfaces come up, this flag
stopped getting set automatically.

see 9374e45449ffe5c377e4cb2a346129ec598eeea9
and github issue #1477
---
 RELEASE-NOTES.md           | 2 ++
 osdep/LinuxEthernetTap.cpp | 1 +
 2 files changed, 3 insertions(+)

diff --git a/RELEASE-NOTES.md b/RELEASE-NOTES.md
index 22bf76dd1..e40967398 100644
--- a/RELEASE-NOTES.md
+++ b/RELEASE-NOTES.md
@@ -1,5 +1,7 @@
 ZeroTier Release Notes
 ======
+# 2021-11-00 -- Version 1.8.2
+ * Fix multicast on linux.
 
 # 2021-10-28 -- Version 1.8.1
 
diff --git a/osdep/LinuxEthernetTap.cpp b/osdep/LinuxEthernetTap.cpp
index acf972682..181c558be 100644
--- a/osdep/LinuxEthernetTap.cpp
+++ b/osdep/LinuxEthernetTap.cpp
@@ -213,6 +213,7 @@ LinuxEthernetTap::LinuxEthernetTap(
 			return;
 		}
 
+		ifr.ifr_flags |= IFF_MULTICAST;
 		ifr.ifr_flags |= IFF_UP;
 		if (ioctl(sock,SIOCSIFFLAGS,(void *)&ifr) < 0) {
 			::close(sock);