Next up was a TP-LINK TL-WR841N, a single band (2.4GHz) N router running its latest firmware, released in October 2014. As shown above, the router can block up to 32 'network services'. Simply adding 192.168.100.1 as a 'Destination IP' in the Network Services Filter Table blocked the modem. Here you can block a destination IP address. In the Firewall section, there is a Network Services Filter tab. Using the web interface of each router (192.168.55.1) I tried to block access to my Motorola modem.ĪSUS The first router I tested was an Asus RT-N56U, a dual band N router, running firmware released in January 2015. Each router happily sent the request for this private IP address out its WAN port. Again, this coming from a 192.168.55.x network.Īs I mentioned last time, you might expect a router to realize that 192.168.100.1 is an internal-use-only IP address, and thus, not let requests for it leave the WAN port. In each case, the computer connected to the three test routers was able to access the main router web interface (192.168.4.1), the modem on 192.168.100.1 and the Internet. To these three routers, 192.168.4.1 was their default TCP/IP gateway and 192.168.4.100 was their WAN-side IP address.Įach router had a single computer connected to it, via Ethernet. That is, the main LAN is 192.168.4.x and, before connecting the routers to it, they were configured to use 192.168.55.x. Each router had its own network, separate from the main LAN. Three routers were tested by connecting them to my LAN. As you would expect, the procedure and terminology was totally different in each router. I tested four routers, and found that three of them could block access to the modem. But here, we need to control outgoing traffic. Steve Gibsons Shields UP! service, for example, lets us verify that the firewall is blocking incoming data. Normal interactions with the firewall in a router are concerned with incoming traffic. That is, we need to configure the router to block WAN side access to 192.168.100.1. There is no problem to solve.īut how to defend an Arris/Motorola modem?īy telling the router not to let us talk to it in the first place. If your modem has no clickable buttons, or any other parameters that you can change, you're done. To keep the password always available, consider writing it down on a piece of paper, along with the IP address of the modem and taping it, face down, to the modem. Needless to say, if your modem offers password protection, changing the default password makes you safer. Just how much of a hassle is it if the modem is reset? I don't know, but neither do I want to find out the hard way.

Mac address on arris modem