diff --git a/nixos/network/config.nix b/nixos/network/config.nix
index 286645a..f18d3ed 100644
--- a/nixos/network/config.nix
+++ b/nixos/network/config.nix
@@ -36,6 +36,14 @@ let
       lanInterfaceIPAddress = calc.cidr.host 1 lanCfg.ipv4.range;
       netmask =  calc.cidr.netmask lanCfg.ipv4.range;
       networkPrefix = builtins.elemAt (lib.splitString "/" lanCfg.ipv4.range) 1;
+      dhcpStartAddress =
+        if (lanCfg.ipv4.dhcp.startAddress != null)
+        then lanCfg.ipv4.dhcp.startAddress
+        else (calc.cidr.host 2 lanCfg.ipv4.range);
+      dhcpEndAddress =
+        if (lanCfg.ipv4.dhcp.endAddress != null)
+        then lanCfg.ipv4.dhcp.endAddress
+        else (calc.cidr.host ((calc.cidr.capacity lanCfg.ipv4.range) - 2) lanCfg.ipv4.range);
 
       createLanInterface = pkgs.writeShellScript "create-lan-${lanCfg.name}-vmix" ''
         ip link add ${lanInterfaceName} type bridge
@@ -47,7 +55,7 @@ let
       lanDomainName = "${lanCfg.name}.vmix";
       lanDnsmasqConf = pkgs.writeText "dnsmasq-${lanCfg.name}.conf" (''
         listen-address=${lanInterfaceIPAddress}
-        dhcp-range=${lanCfg.ipv4.dhcp.startAddress},${lanCfg.ipv4.dhcp.endAddress},${netmask},12h
+        dhcp-range=${dhcpStartAddress},${dhcpEndAddress},${netmask},12h
         interface=${lanInterfaceName}
         bind-interfaces
         except-interface=lo
diff --git a/nixos/network/options.nix b/nixos/network/options.nix
index f69457d..9dc1c8a 100644
--- a/nixos/network/options.nix
+++ b/nixos/network/options.nix
@@ -118,11 +118,13 @@ with vmixLib.network;
           dhcp.startAddress = mkOption {
             type = types.nullOr (types.strMatching regex.ipv4);
             description = "Starting IP Address for DHCP clients.";
+            default = null;
           };
 
           dhcp.endAddress = mkOption {
             type = types.nullOr (types.strMatching regex.ipv4);
             description = "Ending IP Address for DHCP clients.";
+            default = null;
           };
 
           dns.upstream = mkOption {