198
votes
DDoS: Why not block originating IP addresses?
Let's say that you run a shop. Every day, you might get a few hundred customers.
One day, you get tens of thousands of people coming in, who get in the check-out line, buys a trinket, and then gets ...
- 1,331
169
votes
Accepted
Is there any actual security benefit to restricting foreign IP addresses?
The concept is "reducing the threat surface". If there is an expectation that no connections will be made from a certain geographic area, then it makes sense to block that area, because, by definition,...
- 132k
164
votes
Accepted
Can someone steal my IP address and use it as their own?
Network engineer with Border Gateway Protocol (BGP) experience here.
Yes. But usually the attack would have to be for a larger address block and (as Eevee commented) require an attacker with ...
- 1,522
117
votes
DDoS: Why not block originating IP addresses?
TL; DR
The multiple source IPs are what makes them so hard to defend against.
For the longer answer we look at the name. DDoS attack. That first D stands for distributed. In other words, there is no ...
- 5,185
93
votes
Accepted
Can a hacker, that knows my IP address, remotely access accounts I have left logged in on my computer?
No, they would have to have access to your browser cookies in order to abuse them to log into a site you left logged in. Merely knowing your public IP address would not allow them to log into any ...
- 67.3k
93
votes
Accepted
Is it possible to spoof an IP address to an exact number?
You can change your IP to whatever you want; that's trivial. But that will not work the way you want to.
Let's say the store's ISP is Apple Networks, and their IP range is 1.2.3.0 to 1.2.3.255. You ...
- 55.5k
75
votes
Can someone get my home address if I click on a link to a IP logger?
First: almost every single site out there is an "IP logger". Every server logs at least this information:
IP address of the client
Browser type and version
Operating system
Which site they came from (...
- 55.5k
72
votes
Accepted
Can I change my public IP address to a specific one?
You can send out a packet with whatever IP address you like.
Then, one of the routers along the way might decide the packet makes no sense (it is a "martian packet") and discard it. Consider ...
- 23k
71
votes
What does a website see if I am connected on my native IP and then enable my VPN?
Since you asked specifically what the website will see, rather than any intermediary watching your network connection, we should think in terms of requests:
Your old ("native") IP will disconnect any ...
- 3,920
70
votes
Accepted
How fast can hackers change their IP address?
Botnet
If someone has access to a botnet, even a small one, they could change the IP that their actions are coming from several times per minute or flood their actions from a million IPs in any given ...
- 132k
69
votes
Accepted
More than three domains hosted on the same IP address
This is not a sign of a problem for your server. There's an important detail here, which is:
104.27.182.86 is not your server. That IP belongs to cloudflare.
Cloudflare provides a large number of ...
- 31.7k
59
votes
Accepted
How do hackers find the IP address of devices?
Connecting 'things' to the Internet is becoming common because of the benefits of remote communication. You can have your camera upload its footage to a cloud storage server, or be able to view the ...
- 132k
51
votes
How did the brute-forcers get my IP address so quickly?
An IP address is nothing private. Nowadays it's possible to scan the entire IPv4 Internet within minutes. ZMAP, for example, is a tool that can be used for such scans.
NMAP can be used on IP addresses ...
- 651
48
votes
What information can you get with only a private IP address?
Private IP addresses as defined by RFC 1918 (10.0.0.0/8, 172.16.0.0/12 & 192.168.0.0/16) can be used as anyone wishes, so a private IP address alone does not tell much and nothing is definite. ...
- 19.4k
46
votes
Accepted
Are certificates without DNS fundamentally flawed?
However, in this scheme, couldn't an impostor just present the
certificate after getting it from the real server?
An impostor cannot present, and take advantage of, the real server's certificate ...
- 73.3k
40
votes
Can someone steal my IP address and use it as their own?
If someone manage to get a backdoor program installed on your computer, they can route all their traffic through it using it as a proxy server, thus "stealing" your ip.
All their activity will show ...
- 519
39
votes
Which IP address would be most safe and suitable to use as a placeholder in a live system?
I recommend using an address in one of the TEST-NET networks (192.0.2.0/24, 198.51.100.0/24, and 203.0.113.0/24) documented in RFC 5737 and RFC 5735 (link below). Pay attention to the Operation ...
- 2,260
34
votes
How fast can hackers change their IP address?
No one seems to have addressed this yet, but I'd like to introduce the biggest problem to IP based rate limiting: IPv6.
If you (naively) applied the same logic as you do to IPv4 addresses to IPv6 ...
- 4,025
32
votes
More than three domains hosted on the same IP address
This is perfectly normal. There is a big shortage of IPv4 addresses. In fact, we should have run out of them a long time ago. But since so much infrastructure is based on IPv4, it keeps getting "...
29
votes
Accepted
Is my iPhone being targeted by the US Department of Defense?
I don't believe you (or anyone else) is targeted by the US Department of Defense. More plausibly, AT&T screwed up something on their server.
A very quick research on the number 1111301000 returns ...
- 577
29
votes
Can two locations in the same city at the same time have the same IP adress?
Details here depend on your specific ISP setup, but it might well be that multiple customers share the same public IP address. This is called NAT or in case of ISP CG-NAT (carrier grade NAT). It is ...
- 208k
28
votes
Someone has my ip address and is threatining to find and leak my personal information
Don't worry too much
It is relatively easy for someone to get your IP address, they just need to get you to visit a website they control. Some forums let people include links to images, which your ...
- 34.7k
27
votes
DDoS: Why not block originating IP addresses?
In addition to @Hollowproc's excellent answer, the actual "addresses" being used as sources are often spoofed in an attack like this. An attacking host can pretend to be any number of other IPs, ...
- 73.3k
27
votes
How do hackers find the IP address of devices?
It's now possible to scan the entire IPv4 Internet in a matter of minutes using a tool like ZMAP or masscan
Likewise they can use online databases like Shodan and scans.io to find huge lists of a ...
- 14.3k
25
votes
Securing a LAN that has multiple exposed external Cat 6 cable runs?
Options that come to mind:
Use a Managed Switch to provide access control by physical port.
For each physical port, only a specific IP address can be allocated (i.e. that of the camera) This may ...
- 14k
25
votes
Can a hacker, that knows my IP address, remotely access accounts I have left logged in on my computer?
There are few malicious things people can do if they know your public IP address, and the main two are router hacking and DDoS.
Router hacking involves someone scanning your router, and depending on ...
- 55.5k
22
votes
Accepted
How to ensure identity for server-to-server communication over IP
Basically you are trying to re-invent certificate based authentication since you only have an IP address and not a domain.
But certificate based authentication can be used without a domain too, for ...
- 208k
18
votes
How fast can hackers change their IP address?
If a hacker is in posession of a botnet, they can have control over thousands of IP addresses and can switch between them at will. So there is not really a practical limit to the frequency and speed ...
- 34.4k
17
votes
What does a website see if I am connected on my native IP and then enable my VPN?
Your old http session will end and a new one will start. If you haven't so much as switched to a new browser, the site will be able to very easily figure out that you're the same person, just coming ...
- 6,578
Only top scored, non community-wiki answers of a minimum length are eligible