Re: How naked am I?

[Mihira Fernando <mihiratheace@gmail.com>]

On 04/28/2011 01:15 PM, pecondon@mesanetworks.net wrote:
> Day before yesterday (26 apr 2011) I installed newly released software on my wheezy computers on my home LAN. Yesterday, I woke up to find that none of these computers could communicate with my router (a DLink DI-604, no longer offered by DLink).
> I established that it was not bad cables by swapping cables. Every cable worked in some situation, but none worked when connected to the router. This has been working since early 2005, through many software upgrades, but yesterday not so great.
>
> Strange part of the problem is that an Apple AirPort which was also connected to the router for use by my daughter with her
> Mac laptop continued to function through multiple cable changes and power cyclings. But late afternoon, it also quit.
>
> I had been having some paranoid fears about the DLink router over the last month and decided to go out and buy a more modern
> home grade router at Best Buy (brand name Netgear, the box said it worked with Linux). I brought it home and more difficulties. These computers all have wheezy installed using a business card CD of squeeze. To change / fix /experiment with different software, I need a working Internet connection, but I can't configure my new router because I can't ping it. But the Apple AirPort seems to be happy with the new router without any configuration, so I try to install Squeeze on one of my computers and just using whatever DHCP gets found by the new router, or whatever resources the business-card CD can
> access.
>
> It works! My one computer gets loaded with Squeeze and allows me to log on to my ISP's web mail access to my email account via Iceweasel browser. So I can pester you wonderful people for help. My first issue is: I have done nothing about NAT or
> any sort of firewalling. Does the way I installed, using DHCP service from somewhere (perhaps coded into the busiCard CD??)
> Does that include firewalling by default? What do I have in the way of protection? Any?
>
> How do I discover what, exactly I have? Etc. How naked am I?
>
> Paul E Condon
> pecondon@mesanetworks.net
Its very likely that DHCP is offered by your router and the router does 
the NATing for your local network. Home routers are set to do both of 
these by default. Also other than allowing ICMP traffic to the router, 
by default home routers doesnt allow any traffic from the net in to the 
LAN. However some routers do have Telnet or SSH ports open on the router 
so thats the first thing you need to look out for. If these ports are 
open, then since the router still uses the default password, someone can 
get into your router and after that, to your LAN.
A simple : route -n will show you the default gateway used by your PC 
and this is most likely to be the new router.
http://router.ip.address  is likely to give you the web based control 
panel of the router and from there you can setup firewalls, change 
router passwords, etc.

For more exact information you will have to look at the router's 
documentation, which will have the default IP, username and password of 
the router. As well as details on how to configure it from the web based 
panel

Regards,
Mihira.