From 43a45064a0975acef2f95bd0c41eafdcfa6cbafc Mon Sep 17 00:00:00 2001
From: Devin Teske <dteske@FreeBSD.org>
Date: Mon, 8 Feb 2016 17:47:36 +0000
Subject: [PATCH] Adjust MAC allocation algo to support layering

---
 share/examples/jails/jib | 11 +++++++++--
 share/examples/jails/jng |  5 ++++-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/share/examples/jails/jib b/share/examples/jails/jib
index e48f5c49fda..890c1682e9c 100755
--- a/share/examples/jails/jib
+++ b/share/examples/jails/jib
@@ -267,8 +267,15 @@ jib_addm()
 		10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
 		13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
 		esac
-		eiface_devid_a=2:$quad$eiface_devid_a
-		eiface_devid_b=6:$quad$eiface_devid_b
+		case "$iface_devid" in
+		?2:*|?6:*)
+			eiface_devid_a=a:$quad$eiface_devid_a
+			eiface_devid_b=e:$quad$eiface_devid_b
+			;;
+		*)
+			eiface_devid_a=2:$quad$eiface_devid_a
+			eiface_devid_b=6:$quad$eiface_devid_b
+		esac
 		num=$(( $num >> 4 ))
 		quad=$(( $num & 15 ))
 		case "$quad" in
diff --git a/share/examples/jails/jng b/share/examples/jails/jng
index bb63cd675bd..0d9132e23ff 100755
--- a/share/examples/jails/jng
+++ b/share/examples/jails/jng
@@ -297,7 +297,10 @@ jng_bridge()
 		10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
 		13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
 		esac
-		eiface_devid=2:$quad$eiface_devid
+		case "$iface_devid" in
+		?2:*) eiface_devid=a:$quad$eiface_devid ;;
+		*) eiface_devid=2:$quad$eiface_devid
+		esac
 		num=$(( $num >> 4 ))
 		quad=$(( $num & 15 ))
 		case "$quad" in