diff --git a/Info/CiscoStack.pm b/Info/CiscoStack.pm
index 74e2ee22..76b370e6 100644
--- a/Info/CiscoStack.pm
+++ b/Info/CiscoStack.pm
@@ -214,7 +214,7 @@ sub i_speed_admin {
     my $partial = shift;
 
     my %i_speed_admin;
-    my $p_port  = $stack->p_port();
+    my $p_port  = $stack->p_port() || {};
     my %mapping = reverse %$p_port;
     my $p_speed = $stack->p_speed( $mapping{$partial} );
 
diff --git a/Info/Layer1/Bayhub.pm b/Info/Layer1/Bayhub.pm
index 16ff1856..e7a1267e 100644
--- a/Info/Layer1/Bayhub.pm
+++ b/Info/Layer1/Bayhub.pm
@@ -284,7 +284,7 @@ sub set_i_up_admin {
     my $bayhub = shift;
     my ( $setting, $iid ) = @_;
 
-    my $i_index         = $bayhub->i_index();
+    my $i_index = $bayhub->i_index() || {};
     my %reverse_i_index = reverse %$i_index;
 
     $setting = lc($setting);
diff --git a/Info/Layer2/C2900.pm b/Info/Layer2/C2900.pm
index 8bb2cffc..e309d3e6 100644
--- a/Info/Layer2/C2900.pm
+++ b/Info/Layer2/C2900.pm
@@ -95,7 +95,7 @@ sub i_duplex {
     my $partial = shift;
 
     my $interfaces     = $c2900->interfaces($partial);
-    my $c2900_p_index  = $c2900->c2900_p_index();
+    my $c2900_p_index  = $c2900->c2900_p_index() || {};
     my $c2900_p_duplex = $c2900->c2900_p_duplex();
 
     my %reverse_2900 = reverse %$c2900_p_index;
@@ -119,7 +119,7 @@ sub i_duplex_admin {
     my $partial = shift;
 
     my $interfaces    = $c2900->interfaces($partial);
-    my $c2900_p_index = $c2900->c2900_p_index();
+    my $c2900_p_index = $c2900->c2900_p_index() || {};
     my $c2900_p_admin = $c2900->c2900_p_duplex_admin();
 
     my %reverse_2900 = reverse %$c2900_p_index;
@@ -146,8 +146,8 @@ sub set_i_speed_admin {
     # map speeds to those the switch will understand
     my %speeds = qw/auto 1 10 10000000 100 100000000/;
 
-    my $c2900_p_index = $c2900->c2900_p_index();
-    my %reverse_2900  = reverse %$c2900_p_index;
+    my $c2900_p_index = $c2900->c2900_p_index() || {};
+    my %reverse_2900 = reverse %$c2900_p_index;
 
     $speed = lc($speed);
 
@@ -166,8 +166,8 @@ sub set_i_duplex_admin {
     # map a textual duplex to an integer one the switch understands
     my %duplexes = qw/full 1 half 2 auto 3/;
 
-    my $c2900_p_index = $c2900->c2900_p_index();
-    my %reverse_2900  = reverse %$c2900_p_index;
+    my $c2900_p_index = $c2900->c2900_p_index() || {};
+    my %reverse_2900 = reverse %$c2900_p_index;
 
     $duplex = lc($duplex);
 
diff --git a/Info/Layer3/Passport.pm b/Info/Layer3/Passport.pm
index c808ae03..8c6075b2 100644
--- a/Info/Layer3/Passport.pm
+++ b/Info/Layer3/Passport.pm
@@ -188,7 +188,7 @@ sub interfaces {
         )
         )
     {
-        $vlan_index   = $passport->rc_vlan_if();
+        $vlan_index   = $passport->rc_vlan_if() || {};
         %reverse_vlan = reverse %$vlan_index;
         $vlan_id      = $passport->rc_vlan_id();
     }
diff --git a/Info/MAU.pm b/Info/MAU.pm
index 580b88ed..5be2ac92 100644
--- a/Info/MAU.pm
+++ b/Info/MAU.pm
@@ -170,16 +170,15 @@ sub mau_i_duplex_admin {
     my $mau     = shift;
     my $partial = shift;
 
-    my $mau_index     = $mau->mau_index();
-    my %rev_mau_index = reverse %$mau_index;
-    my $mau_autostat
-        = defined $partial
-        ? $mau->mau_autostat( $rev_mau_index{$partial} )
-        : $mau->mau_autostat();
-    my $mau_type_admin
-        = defined $partial
-        ? $mau->mau_type_admin( $rev_mau_index{$partial} )
-        : $mau->mau_type_admin();
+    my $mau_index = $mau->mau_index() || {};
+
+    if ($partial) {
+        my %rev_mau_index = reverse %$mau_index;
+        $partial = $rev_mau_index{$partial};
+    }
+
+    my $mau_autostat   = $mau->mau_autostat($partial)   || {};
+    my $mau_type_admin = $mau->mau_type_admin($partial) || {};
 
     # Older HP4000's don't implement ifMauDefaultType, but we can
     # figure out from ifMauAutoNegCapAdvertised what we'd like.