router hack

[bwanaaa]

Well, i have a consumer grade netgear router that can route 255 addresses-not that you'd want to. But the usual subnet mask for this kind of thing is 255.255.255.0

What happens when you plug in 255.255.240.0?

I can still access the internet and and still route all my lan ips. I just cant access the router from the lan. But now i can get to it from the wan!? Remote management, hehe. I guess i did a buffer overload on it-after all with a subnet mask of 255.255.240.0 I am telling the router it can route 16x256=4000 addresses, even though it cannot.

 

[eliteorange]

FYI subnet mask is used to distinguish host bit and network bit from the IP.... and IP is a routed protocol not a routing protocol, whatever u just typed makes so sense at all

 

[foshizzle]

I think that he's just asking if you could cram more users onto a router by loosening the mask that the router uses. ie, a network using a mask of 255.255.0.0 would handle ~255^2 users. At least that's what I think he's asking.

 

[gunrunnerjohn]

And I believe the answer is no.

 

[bwanaaa]

I guess the only way to find out would be to actually try to connect more than 255 users because the thing still runs my small network. Of course the bandwdth for every user would suck.

But more to the point, why the does the router still function but NOT let me access it, except from the wan?!

I think pc viruses are small fry compared to a virus that could mess up routers. Is there any bbs or info anywhere on router security?

 

[bwanaaa]

That I am a noob is evident. that doesn't explain why a router designed to support <255 users (subnet mask 255.255.255.0)will still function with a subnet mask 255.255.240.0 or 255.255.0.0 for that matter? The thing still lets my little network function, I just cant access its configuration page from the lan, only the wan. Why cant i find my router from my lan? Did I not screw up its id by telling it that it can address more lan ips than it actually can(overflow?)

In terms of hacking the router, I can tell you that setting the subnet mask to 255.255.0.0 permitted a vpn to be established through the following configuration:

In my department:
vpn router Lan ip:192.168.3.1
wan ip :10.xxx.xxx.77
|
V
nat router with firewall in my building
lan ip: 10.xxx.xxx.1
wan ip: 208.xxx.xxx.xxx
|
V
INTERNET
(many hoops)
|
V
other office
vpn router: wan ip: 141.xxx.xxx.xxx
lan ip: 192.168.1.1

As you wizards (Terminx, Frenzy,breakapart) undoubtedly already know (sigh), vpn with IPSEC should not work with 2 vpn servers if there is a nat router in the middle because the address headers on the packets are changed as they pass through NAT.

so why does it work? i have an idea, but saying it that might only expose me to more flames from those of you with just a little more knowledge than me. How about you tell me why it works?

On a broader level, I thinkk that router hacks such as these (compromising a nat firewalll for example) pose a much greater threat to the net than any pc virus. Is there a site (web, ftp, bbs,blog or otherwise)that addresses issues with router security and hacks?

 

[foshizzle]

I'm pretty sure there aren't viruses, that are targetted towards routers, unless you were to flash the router bios with one.

 

[bwanaaa]

Well if the router supports uPnP then you can access its bios directly-but right now the only way to cripple a network is DDOS. imagine if you could redirect traffic.

Still dont understand why you cant access the router config page.

Why do you climb through the nat when you expand the subnet?

My guess is that one LAN runs 192.168.1.x and the other runs 192.168.3.x. Both of these ip ranges are included by the 255.255.0.0 subnet of a 192.168.3.1 gateway or a 192.168.1.1 gateway. As long as you get a ping back from the nat router, the the router falls into the 'shadow' of the other router's subnet. Certainly a bug.

But this doesnt really explain why the router page cant be accessed.