Skip to main content

router - Two public IPs behind a cable-modem using D-Link DIR-300


I have a cable-modem connection to the internet and I bought a router in order to share my internet connection betwen my laptop and my PC.


The router I bought is D-Link DIR-300.
The first weird thing I notice after connecting all the wires and cables was that my laptop had direct connection to the internet (public IP) even though it was connected to the router (not the cable modem).


After that I connected my PC to the router, and to my surprise my PC got a public IP as well (a new IP, different from that of my laptop).


If I ping from my laptop to my PC (and vice versa) I get a successful response, meaning my PC and laptop can reach each other, but not through a private LAN (which doesn't exist in my case because both computers were given public IPs) but through the internet.
The ping between the two computers takes about 20 ms which is clearly a ping through the internet given that a ping through a private LAN takes 1 ms or less.


I also tried a D-Link DI-604 for testing, but that didn't happen. With the DI-604 my two computers were given private IPs as normal, so clearly the DIR-300 router is making the difference here.


So my question is... How is it possible to have two different public IPs behind a cable-modem and a router?
Is it some weird feature in DIR-300 that allows that?



Answer



Depending on your ISP, some will supply you with multiple IP addresses. Mine only allows 1 lease at a time though. Your router is likely configured to allow the use of multiple IPs if available, although you can change it to only use 1 if you'd like.


Comments

Post a Comment

Popular Posts

keyboard - Is there any utility/method to change Windows key bindings to type rare chars to currently empty bindings?

I'm currently typing this post with my windows XP machine and (Spanish) keyboard, and I'd like to add some extra symbols to my text. I could open the "char map" windows utility, look for the desired symbols, and paste them. But I'd like something quickier. For example, when I'm using my OSX Mac at work, I can easily add a ©, ™, ® or similar symbols, just pressing some weird ALT-GR + G / H / J, key combinations. In my (Spanish) keyboard mapping, these combinations are empty, as they don't produce any char at all, which, on the other hand, is perfectly normal and desirable. So, I thought: Why couldn't I add some extra key mappings on top of my currently empty ALT-GR + G/J/H Keys in my Spanish keyboard, and thus, being able to quickly type these special symbols? So that's my question: Is there any utility/method to achieve that effect under windows? (My version is XP). I've even googled this for some time but no luck. I've been a long term Hot...
Post a Comment
Read more

virtualization - How to select paravirtualization interface in VirtualBox?

Given a windows 8 host system (Intel Core i5) and a Linux Fedora host, I would like to determine the optimal setting for the paravirtual interface. Options are none Default Legacy minimal Hyper-V KVM This page suggest the selection is only based on the guest system: The biggest change in VirtualBox 5.0 is the introduction of paravirtualization support, bringing higher performance and time-keeping accuracy to supported guest operating systems (Hyper-V on Windows and KVM on Linux). Is that correct? Answer The VirtualBox Manual , in the section titled Paravirtualization providers explains very clearly when each should be used (emphasis added): Minimal: Announces the presence of a virtualized environment. Additionally, reports the TSC and APIC frequency to the guest operating system. This provider is mandatory for running any Mac OS X guests. KVM: Presents a Linux KVM hypervisor interface which is recognized by Linux kernels starting with version 2.6.25. VirtualBox's implementati...
Post a Comment
Read more

Desktop reboots itself on sleep or hibernate

I have been using an ASUS M2NPV-VM motherboard for main home desktop workstation, operating Windows Vista x64. This computer has right from day one not been able to enter hibernate or standby; after Windows performs its final actions and brings the machine down, it would automatically revive itself for a reboot. Updating to the second latest BIOS (1201)has not helped (the latest BIOS revision would induce video refresh problems rendering it unusable). I have been reading related discussions on incidents similar to mine to no avail of a true workable solution. They appear to be more speculative guesses rather than actual knowledge on the inner workings of motherboard hardware. Does anybody have any electronic engineering experience on PC energy-saving standards to provide a more informed opinion how to go about getting this to work? More stories: this motherboard could not even reboot properly the first thing i used it. It was due to refresh rate of the onboard GPU, which had no influe...
Post a Comment
Read more

security - How is Linux not prone to viruses, malware and those kinds of things?

How is Linux protected against viruses? This question was a Super User Question of the Week . Read the blog entry for more details or contribute to the blog yourself Answer Well, it factually is not... it's just less subject to hackers developing viruses that target Linux systems. Consumer grade computers usually run on Windows and thus, when targeting a wide audience, Windows is the way to go. Don't misunderstand Linux and viruses, there definitely ARE Linux viruses. Some distros have additional protection layers such as SELinux (See here ) in Ubuntu for example. Then there's the default firewall and the fact that alien files don't automatically have permission to be executed. Specific execution permission has to be granted before execution is possible. (See here ) Then there are several other factors that make Linux a hard place to be for viruses usually non-root users on linux systems have no to little executable files at their disposal that would allow for virus...
Post a Comment
Read more