Segmenting LAN1 from LAN2

Hello,

I've read several forum posts with instructions on how to segment two LANs from communicating with each other.  I've successfully applied firewall rules to prevent communications between the LANs.  My setup is such:

LAN 1:

eth1

192.168.2.1/24

all inbound traffic on this interface is denied if it is destined for 192.168.1.1/24

LAN 2:

eth2-4

192.168.1.1/24

While traffic on LAN 1 is being blocked from accessing LAN2, I can still access the router interface of LAN2 on LAN1. (i.e. While on LAN 2, I can browse to 192.168.1.1).  How can I prevent users on LAN2 from accessing the management interface of the LAN 1 IP address of the router?