How dynamic are the IP addresses with i-stream?

ceejay

Does anyone know how dynamic the IP addresses that are issued with i-stream are? How often do they change? How does this work exactly, anyway? Is it a DHCP lease that expires, and when you request a new IP address, it may or may not be the same, but is likely to be the same?

Ciarán.

seamus

I assume it's the same as dial-up. When you disconnect and reconnect (eg when you reboot), you may or may not get the same IP, it's a lottery.

However with DHCP, when you renew your lease, your computer first tries to get the same IP, so normally you will get the same IP. The time between releasing/renewing the IP lease is so small that nomally another computer requesting an IP will not be able to get your IP, unless there are a lot of requests going through the server.

In fact with any sort of dial-up stuff you get assigned a hostname and IP to identify you on the net, so when renewing IPs it makes more sense to allow the computer keep the same IP. As I said though, when you disconnect and reconnect, it's a lottery as to what IP you receive (probably)

ceejay

OK, but say you've got an always-on computer connected to always-on i-stream. Will it keep it's IP address until it's rebooted, perhaps keeping the same IP address when/if the address lease expires?

Ciarán.

ozpass

As with most things IP related, it's based on the MAC address of the network card that's requesting the IP address. On a LAN the leases will usually be configured in days, but this isn't really relevant in the case of an ISP where the lease expires with the connection. There is more contention for IP's with many computers requesting IP's within the same time frame. Hence you'll more than likely get a different IP address each time you reconnect.

I'm going to make an assumption here: namely that you're interested in accessing portions of your computer over the internet when you're away from home- maybe some web services, but can't guarantee what your IP will be if the connection status changed. If that's true- I have a solution for you. Lots of my mates in the UK with their £20 a month always on ADSL (bastards) use Deerfield's (www.deerfield.com) DNS2Go which involves running a client on your PC. You choose a domain and register it with Deerfield e.g. joebloggs.myspace.com. Whenever the connection is dropped and reinstated, the client tells Deerfield's servers the new IP and it gets entered dynamically into their DNS servers. Result: typing the URL/pinging/whatever joebloggs.myspace.com will always reach your computer. I haven't done this myself, mind, but there are loads of free services of this type available on the 'net: just Google to find one suitable for yourself.

Also bear in mind that Eircom wont like you running web services on your machine. Try using a high up wonky port number and hope they don't notice or think you're using peer-to-peer.

lynchie

Leases are usually obtained for about 3 weeks. So even if you do shut your machine down for a two week period, you will more than likely get your same ip adress back once you connect again. The only reason you may not get your lease back is when the dhcp server is under a heavy load and it has to give a previously leased out ip adress to a new client.

If somebody on i-stream could check the results of an ipconfig /all, it would show how long the leases are.

Dustaz

As i said on another thread, just get a dynamic DNS from www.dyndns.org (actually, mine is from www.mine.nu ).

Its all free and very workable. whenever i leave an ftp server up its at dustaz.mine.nu:21 . I can get to it from work with no probs.

strat

Originally posted by Dustaz
As i said on another thread, just get a dynamic DNS from www.dyndns.org (actually, mine is from www.mine.nu ).

Its all free and very workable. whenever i leave an ftp server up its at dustaz.mine.nu:21 . I can get to it from work with no probs.

rofl curosity killed the cat and all that

~ Connected to dustaz.mine.nu, waiting for response...
< 220 Eircom FTP version 1.0 ready at Mon Jan 10 02:40:07 2000
> USER anonymous
< 331 Enter PASS command
> PASS *****

Dustaz

BREACH OF SECURITY!!!!!!!