Dangers of giving out IP addresses?

Soldato
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Just a noob question but I used to hear lots that its dangerous to give out your ip address.

Why is this?

Its not. This would have been the case years ago where security by obscurity was the phrase of the week, but you have just as much chance of being hacked etc if you don't give it out.

If you have an up to date firewall/anti virus/anti spyware, then you really shouldn't need to worry.

Saying that, why would anyone want to know your IP address?
 
Man of Honour
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It's not terribly dangerous but I wouldn't publish it online or something silly like that, it's not dissimilar to giving out your street address at the end of the day. Not going to kill you if people find out and easy enough for someone to find if they want but you don't go announcing it to everyone down the pub...
 
Man of Honour
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Rough location? As in the right country?

Depends on the ISP and how diligent they are...anything larger than a /29 registered should have the user address on the RIPE database really.

If you're running NAT they'll only see the outside of your router, which I expect covers most people here (and those, like me, running public IPs internally will likely have enough experience to have a decent firewall)
 
Associate
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Depends on the ISP and how diligent they are...anything larger than a /29 registered should have the user address on the RIPE database really.

If you're running NAT they'll only see the outside of your router, which I expect covers most people here (and those, like me, running public IPs internally will likely have enough experience to have a decent firewall)

whats a decent firewall that could be used and what are the benefits of it?
 
Man of Honour
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no as in area and what isp server you're going from. I've put a post on here about a problem i've got where someones gained access to my wifi internet and caused some problems and an email I had came back with my routers ip address and the location of the nearest isp location/centre thing

Bear with me here....

Well the basics are technically that all the IPs out there are divided into blocks, these are given to regional registries to assign. The registry responsible for the UK (and europe etc) is called RIPE, they hand out these blocks of IPs (usually 8000+ at a time) to ISPs, as part of this RIPE know which country and which ISP an IP belongs to automatically. No way of guarding against that.

Your ISP will likely not mark single IPs according to which user they belong to, they'll just take a group (maybe a few hundred, maybe thousands depending on size) and say to RIPE 'this is for our broadband customers' - important note here is ISPs must account for their IP usage to RIPE to ensure they're used efficiently.

If you have a larger block of IPs though then they'll likely register it with RIPE as being assigned to you...for instance if you run a whois on the IP address of the BBC site you'll get a name and telephone number for someone. In theory that information is available for every IP - but for home users the ISP takes responsibility rather than publishing the details.

The point being, if somebody has your IP, tracking it to a country and ISP is trivial and impossible to prevent. Tracking to an address or similar is easy for blocks of IPs but generally not for single IPs. If somebody misused your connection then don't be surprised if you get an email or letter about it, you're fairly easy to track down as the owner. Whether they can hold you liable for misuse - ask a lawyer rather than take the word of anyone on here.
 
Man of Honour
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whats a decent firewall that could be used and what are the benefits of it?

I use a Juniper SSG20, it's an enterprise class small office firewall and it's great, hugely configurable and powerful. Great control of policies, good logging, can do intrusion detection and deep inspection if required. It's also massively OTT for home use and costs about £900 with the ADSL module in it - I wouldn't recommend it in a million years! I just work for an ISP.

If you want to get to grips with security and have a really good router/firewall the Cisco 800 series are good kit but hard going to configure if you don't know the command line. If you just want something that works and you're using NAT anyway (ie. your computers have 192.168.x.x or 10.x.x.x addresses) then a decent consumer box should do everything you need. Somebody else will be better than me to recommend something, I haven't played with anything but the high end gear for years...
 
Associate
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Depends on the ISP and how diligent they are...anything larger than a /29 registered should have the user address on the RIPE database really.

If you're running NAT they'll only see the outside of your router, which I expect covers most people here (and those, like me, running public IPs internally will likely have enough experience to have a decent firewall)

Whats NAT? and how do you know if its running?
 
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