DSL Router & Forwarding Ports Problem

If you read my previous post on Troubleshooting Ports on DSL, then perhaps you will get the whole idea on how to forward ports, but as I discovered, powering off your routers may cause packet loss afterwards.

In a typical DSL setup your main DSL modem provide DHCP services, and although there is only one physical ethernet port that it connects to, unless you specifically setup the DSL modem to forward all traffic to your LAN router, chances are a reset could send packets to another ip address and all of a sudden your packets get lost going to a different ip.

To work around this, you either have to be careful about how you reset your routers or force the DSL modem to route everything to one IP address, therefore losing some of the firewall protection that the DSL modem is providing.

Here is a proper way to reset your home network and routers.

1. Turn off everything. This includes computers, routers, DSL modem.

2. Power on the DSL Modem first. Wait a few minutes until the LAN and WAN lights turn solid, usually green.

3. Power on your home router, the Linksys, Netgear, D-Link, or whatever brand you have.

4. After a couple of minutes, turn on the computers and other devices on your network.

5. Verify the NAT on the DSL modem is still setup properly and that the home router is connecting to the DSL modem with the correct IP address.

For the Cisco 678 ADSL modem, telnet into it and type:

show nat

The last lines that come up will show the last packets that were sent and what local ip they were sent to. It should be 10.0.0.2 for the 678, unless you changed it.