Technical Discussion
  >> Home Networking, Internet Connection Sharing, etc.


Register (or login) on our website and you will not see this ad.


  Print Thread
Standard User loopfish
(newbie) Mon 09-Jan-12 23:02:26
Print Post

VM dynamic IP, yet TBB Ping Monitor sees same IP...


[link to this post]
 
Hi,
can anyone explain why my Asus RT-N56U wireless router gives a different (but always the same) public IP address (for example the IP that TBB Ping Monitor registers) to that which is displayed when I disconnect my router?

I am on Virgin Media 10MB cable, and connect my PC via Cat5 to the router, then Cat5 to the cable modem. Nothing else.

The router always gives out the same IP address (86.21.124.xx) regardless of what Virgin Media renew my actual IP address to...

This is great from the point of view that I can use the TBB Ping Monitor 24/7! laugh but also slightly confusing...
Sam
Administrator MrSaffron
(staff) Tue 10-Jan-12 08:54:45
Print Post

Re: VM dynamic IP, yet TBB Ping Monitor sees same IP...


[re: loopfish] [link to this post]
 
Dynamic IP's are issued based around leases, and with many providers if you reconnect inside a period of 24 hours you get the same IP address

Often called a sticky IP as a way of explaining it

Andrew Ferguson, andrew@thinkbroadband.com
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User loopfish
(newbie) Tue 10-Jan-12 09:07:30
Print Post

Re: VM dynamic IP, yet TBB Ping Monitor sees same IP...


[re: MrSaffron] [link to this post]
 
thanks, I had heard that, but it still doesn't explain why the public IP displayed by my router is different to that displayed by my cable modem (without the router connected)...


Register (or login) on our website and you will not see this ad.

Administrator MrSaffron
(staff) Tue 10-Jan-12 11:19:22
Print Post

Re: VM dynamic IP, yet TBB Ping Monitor sees same IP...


[re: loopfish] [link to this post]
 
Because cable services tend to assign the IP based on the MAC of the network interface presented to it.

So when your router is connected it sees one MAC, and I assume you connect a computer directly to see what IP the modem has, in which case it is really handing it to the computer.

Andrew Ferguson, andrew@thinkbroadband.com
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User loopfish
(newbie) Tue 10-Jan-12 11:39:36
Print Post

Re: VM dynamic IP, yet TBB Ping Monitor sees same IP...


[re: MrSaffron] [link to this post]
 
Thanks, that all makes sense.

It's still a bit odd why my IP seems to change more often with the router disconnected, yet it's always the same IP given with the router connected...it may just be coincidence that the IP renews have occurred when I've been testing without the router...time will tell if my router's IP ever changes!
  Print Thread

Jump to