Hello,
I've used two internet services to show me my IP address, and I get different results:

1. Whatsmyip.org : ***.**.109.***
2. ipchicken.com : ***.**.111.***

All the * numbers are same, except 109 and 111. Could you please explain me (or link me to explanation) of which one's which?

Thanks

A couple of possibilities:

• If the results from the different lookup services were a few hours or days apart, this may just be the normal action of DHCP - your lease on an IP address may have expired between the two readings.
• If the two results were obtained at roughly the same time, your internet service provider (or corporate/academic network) is multiplexing connections, meaning that a large number of users' connections are bening routed onto the internet via a much smaller number of public IP addresses. They may then have some form of load balancing that send different connections via different routes.

Do the results stay consistent over time, for the two sites? And how about if you try a third service, such as ip-lookup.net?

Rob

Hmmm, mine match on those two sites. There are some possible explanations as to why the difference. Lots of isp's assign their users IP addresses with DHCP. The lease could have expired between visits. Next assigned IP address was different.

This kind of thing only matters if you are trying to access your system from elsewhere in the internet, ie, you leave it on for remote access.

The first numbers should be the same for your ISP. There is a net mask, the bits marked with ones in the mask do not change ( or they shouldn't ). If your ISP is a large provider, they may have class B ip addresses, so the first two fields will not change.

Hope this helps.

Chances are you are being NAT'd before you hit the internet and your ISP has an address pool assigned. Each traffic flow will pick up the next address in the pool in a round-robin fashion.

If you post your IPs we're going to have a much better chance of telling you

Thanks for your replies,
ip-lookup.net shows me 111 address, but for example whatismyipaddress.com shows me 109s one. Also, Whatismyip.com displays 111.

IP adresses stay same for same services, as far as I have noticed.

Wonder if it could be browser cache deal.

In a real world you can't have two like that. I guess it could be some flakey device upstream that has a version conflict but that would be weird.

Log on to your router or modem and find the real address.

There are a lot of things that can be done in a network that appear illogical and that you would swear wouldn't work. I worked at one place for a while that had what they called asynchronous routing. Traffic to the internet went out one WAN link and came in on another. It was weird but it worked.

I'm betting this anomaly is just some strange NAT config in the guts of the ISPs network.

Yeah,
I am actually beginner when it comes to "WAN" networks, but I assume that I am just part of bigger subnet of my ISP, as my modem's IP is private (10.251.187.20). Modem is accessible only with 172.30.30.128, which I expect to be "private internal address" (so the first one was private external). What I can't get clearly is that both my modem and router use 10.251.187.19 gateway.