diff --git a/src/PVE/Network/SDN/Ipams/NetboxPlugin.pm b/src/PVE/Network/SDN/Ipams/NetboxPlugin.pm
index af9be25..a691323 100644
--- a/src/PVE/Network/SDN/Ipams/NetboxPlugin.pm
+++ b/src/PVE/Network/SDN/Ipams/NetboxPlugin.pm
@@ -96,6 +96,60 @@ sub add_subnet {
     }
 }
 
+sub update_subnet {
+    my ($class, $plugin_config, $subnetid, $subnet, $old_subnet, $noerr) = @_;
+
+    # old subnet in SubnetPlugin hook has already parsed dhcp-ranges
+    # new subnet doesn't
+    my $old_dhcp_ranges = $old_subnet->{'dhcp-range'};
+    my $new_dhcp_ranges = PVE::Network::SDN::Subnets::get_dhcp_ranges($subnet);
+
+    my $hash_range = sub {
+	my ($dhcp_range) = @_;
+	"$dhcp_range->{'start-address'} - $dhcp_range->{'end-address'}"
+    };
+
+    my $old_lookup = {};
+    for my $dhcp_range (@$old_dhcp_ranges) {
+	my $hash = $hash_range->($dhcp_range);
+	$old_lookup->{$hash} = undef;
+    }
+
+    my $new_lookup = {};
+    for my $dhcp_range (@$new_dhcp_ranges) {
+	my $hash = $hash_range->($dhcp_range);
+	$new_lookup->{$hash} = undef;
+    }
+
+    my $to_delete_ids = ();
+
+    # delete first so we don't get errors with overlapping ranges
+    for my $dhcp_range (@$old_dhcp_ranges) {
+	my $hash = $hash_range->($dhcp_range);
+
+	if (exists($new_lookup->{$hash})) {
+	    next;
+	}
+
+	my $internalid = get_iprange_id($plugin_config, $dhcp_range, $noerr);
+
+	# definedness check, because ID could be 0
+	if (!defined($internalid)) {
+	    warn "could not find id for ip range $dhcp_range->{'start-address'}:$dhcp_range->{'end-address'}";
+	    next;
+	}
+
+	del_dhcp_range($plugin_config, $internalid, $noerr);
+    }
+
+    for my $dhcp_range (@$new_dhcp_ranges) {
+	my $hash = $hash_range->($dhcp_range);
+
+	add_dhcp_range($plugin_config, $dhcp_range, $noerr)
+	    if !exists($old_lookup->{$hash});
+    }
+}
+
 sub del_subnet {
     my ($class, $plugin_config, $subnetid, $subnet, $noerr) = @_;
 
diff --git a/src/PVE/Network/SDN/Ipams/PVEPlugin.pm b/src/PVE/Network/SDN/Ipams/PVEPlugin.pm
index 742f1b1..59ad4ea 100644
--- a/src/PVE/Network/SDN/Ipams/PVEPlugin.pm
+++ b/src/PVE/Network/SDN/Ipams/PVEPlugin.pm
@@ -82,6 +82,11 @@ sub add_subnet {
     die "$@" if $@;
 }
 
+sub update_subnet {
+    my ($class, $plugin_config, $subnetid, $subnet, $old_subnet, $noerr) = @_;
+    # we don't need to do anything on update
+}
+
 sub only_gateway_remains {
     my ($ips) = @_;
 
diff --git a/src/PVE/Network/SDN/Ipams/PhpIpamPlugin.pm b/src/PVE/Network/SDN/Ipams/PhpIpamPlugin.pm
index df5048d..8ee430a 100644
--- a/src/PVE/Network/SDN/Ipams/PhpIpamPlugin.pm
+++ b/src/PVE/Network/SDN/Ipams/PhpIpamPlugin.pm
@@ -67,6 +67,11 @@ sub add_subnet {
     }
 }
 
+sub update_subnet {
+    my ($class, $plugin_config, $subnetid, $subnet, $old_subnet, $noerr) = @_;
+    # we don't need to do anything on update
+}
+
 sub del_subnet {
     my ($class, $plugin_config, $subnetid, $subnet, $noerr) = @_;
 
diff --git a/src/PVE/Network/SDN/Ipams/Plugin.pm b/src/PVE/Network/SDN/Ipams/Plugin.pm
index ab4cae8..6190c24 100644
--- a/src/PVE/Network/SDN/Ipams/Plugin.pm
+++ b/src/PVE/Network/SDN/Ipams/Plugin.pm
@@ -75,6 +75,12 @@ sub add_subnet {
     die "please implement inside plugin";
 }
 
+sub update_subnet {
+    my ($class, $plugin_config, $subnetid, $subnet, $old_subnet, $noerr) = @_;
+
+    die "please implement inside plugin";
+}
+
 sub del_subnet {
     my ($class, $plugin_config, $subnetid, $subnet, $noerr) = @_;
 
diff --git a/src/PVE/Network/SDN/SubnetPlugin.pm b/src/PVE/Network/SDN/SubnetPlugin.pm
index 049f7e1..e73d97a 100644
--- a/src/PVE/Network/SDN/SubnetPlugin.pm
+++ b/src/PVE/Network/SDN/SubnetPlugin.pm
@@ -186,7 +186,11 @@ sub on_update_hook {
     validate_dhcp_ranges($subnet);
 
     if ($ipam) {
-	PVE::Network::SDN::Subnets::add_subnet($zone, $subnetid, $subnet);
+	if ($old_subnet) {
+	    PVE::Network::SDN::Subnets::update_subnet($zone, $subnetid, $subnet, $old_subnet);
+	} else {
+	    PVE::Network::SDN::Subnets::add_subnet($zone, $subnetid, $subnet);
+	}
 
 	#don't register gateway for pointopoint
 	return if $pointopoint;
diff --git a/src/PVE/Network/SDN/Subnets.pm b/src/PVE/Network/SDN/Subnets.pm
index e2c8c9c..18847c2 100644
--- a/src/PVE/Network/SDN/Subnets.pm
+++ b/src/PVE/Network/SDN/Subnets.pm
@@ -194,6 +194,18 @@ sub add_subnet {
     $plugin->add_subnet($plugin_config, $subnetid, $subnet);
 }
 
+sub update_subnet {
+    my ($zone, $subnetid, $subnet, $old_subnet) = @_;
+
+    my $ipam = $zone->{ipam};
+    return if !$ipam;
+
+    my $ipam_cfg = PVE::Network::SDN::Ipams::config();
+    my $plugin_config = $ipam_cfg->{ids}->{$ipam};
+    my $plugin = PVE::Network::SDN::Ipams::Plugin->lookup($plugin_config->{type});
+    $plugin->update_subnet($plugin_config, $subnetid, $subnet, $old_subnet);
+}
+
 sub del_subnet {
     my ($zone, $subnetid, $subnet) = @_;