From de121c54781b92d4287277eefa8fd3eb783c8290 Mon Sep 17 00:00:00 2001
From: Mariusz Zaborski <oshogbo@FreeBSD.org>
Date: Fri, 9 May 2025 11:42:07 +0200
Subject: [PATCH] jail: copy MTU settings to vnet interface

Reported by:	Arne Steinkamm <arne@steinkamm.com>
Reviewed by:	bapt, thj
Differential Revision:	https://reviews.freebsd.org/D48334
---
 share/examples/jails/jng | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/share/examples/jails/jng b/share/examples/jails/jng
index 610b08f9684..53dc680e631 100755
--- a/share/examples/jails/jng
+++ b/share/examples/jails/jng
@@ -314,6 +314,8 @@ jng_bridge()
 			ngctl name $iface:lower ${iface}bridge || return
 		fi
 
+		mtu=$(ifconfig ${iface} | sed -n '1s/^.*mtu //p;') || return
+
 		# Optionally create a secondary bridge
 		if [ "$bridge" != "bridge" ] &&
 		   ! ngctl info "$iface$bridge:" > /dev/null 2>&1
@@ -346,6 +348,7 @@ jng_bridge()
 			echo $2 ) || return
 		ngctl name "$iface$bridge:link$num" $eiface || return
 		ifconfig $new name $eiface || return
+		ifconfig $eiface mtu $mtu || return
 		ifconfig $eiface up || return
 
 		#