From d4ae9237a6d29a2759f2f609141cb1c487d8143f Mon Sep 17 00:00:00 2001
From: Jeroen van Ingen <jeroen@utwente.nl>
Date: Mon, 23 Oct 2017 15:45:04 +0200
Subject: [PATCH] Improve generic Info::Layer3 serial number detection

Serial numbers weren't reported for stackable Layer3::H3C devices, even
when not actually stacked. Report serial number not only if the entity
has no parent, but also if it has a parent but is of type "chassis".

This fixes #232.
---
 Changes                 | 4 ++++
 lib/SNMP/Info/Layer3.pm | 5 ++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/Changes b/Changes
index 098606bc..57c852c5 100644
--- a/Changes
+++ b/Changes
@@ -6,6 +6,10 @@ version 3.38 ()
 
   * Layer2::Airespace several newer 802.11 data rates added
 
+  [BUG FIXES]
+
+  * #232 Improve generic Info::Layer3 serial number detection
+
 version 3.37 (2017-07-11)
 
   [ENHANCEMENTS]
diff --git a/lib/SNMP/Info/Layer3.pm b/lib/SNMP/Info/Layer3.pm
index d7b4d05a..3f3ccae0 100644
--- a/lib/SNMP/Info/Layer3.pm
+++ b/lib/SNMP/Info/Layer3.pm
@@ -196,10 +196,13 @@ sub serial {
 
     my $serial1 = $l3->serial1();
     my $e_parent = $l3->e_parent() || {};
+    my $e_class  = $l3->e_class() || {};
 
     foreach my $iid ( keys %$e_parent ) {
         my $parent = $e_parent->{$iid};
-        if ( $parent eq '0' ) {
+        my $class = $e_class->{$iid} || '';
+        # Only consider serial numbers for entries without a parent, or if they are of type "chassis"
+        if ( $parent eq '0' or $class eq 'chassis') {
             my $serial = $l3->e_serial($iid);
             if ( $serial && $serial->{$iid} ) {
                 return $serial->{$iid};