Why IP address is fixed everytime connected to the Internet?

[apngss]

I want to ask who assigns the IP address to a machine that connects to
the Internet? The ISP, the network card (i.e. MAC address??), or the
router?

It seems like my IP address is fixed everytime connected to the
Internet, it seems very unsecure because it allows hackers track the
computers more easily.

I thought the IP address should be dynamic, and each time when we
connect to the Internet should have different IP address.

Is there a way that makes the IP address in my machine becomes dynamic?

Please advise. thanks!!

 

[Ian]

I want to ask who assigns the IP address to a machine that connects to
the Internet? The ISP, the network card (i.e. MAC address??), or the
router?

It seems like my IP address is fixed everytime connected to the
Internet, it seems very unsecure because it allows hackers track the
computers more easily.

I thought the IP address should be dynamic, and each time when we
connect to the Internet should have different IP address.

Is there a way that makes the IP address in my machine becomes dynamic?

Please advise. thanks!!

Nice crossposting!

Your ISP is assigning your Internet IP Address - You need a static
address if you are:
Hosting a mailserver
Hosting a website
Providing Dialin Access (VPN)

 

[Bit Twister]

I want to ask who assigns the IP address to a machine that connects to
the Internet? The ISP, the network card (i.e. MAC address??), or the
router?

Your ISP.

It seems like my IP address is fixed everytime connected to the
Internet, it seems very unsecure because it allows hackers track the
computers more easily.

Cracker is not going to trust that is fixed. They will have code to
scan ip addresses so trying keep the ip address a secret is a waste of time.

I thought the IP address should be dynamic, and each time when we
connect to the Internet should have different IP address.

Your ISP decides if static or not and if dynamic, IP addy lease time.

Is there a way that makes the IP address in my machine becomes dynamic?

If dynamic, you would have to stay off the net for the dhcp lease
time. Mine is 5 days before it expires. I would then have to wait for
another customer on my segment to let their lease expire and get my ip
or a new customer comes on line and gets my ip addy.

That is a waste of time.

Just set your firewall to block all incomming connections, do not run
browsers and whatnot as root, check everyday for updates from your
linux vendor and you will be supprised how safe you are.

 

[Ted Zieglar]

"I want to ask who assigns the IP address to a machine that connects to the
Internet?"
Your ISP

"Is there a way that makes the IP address in my machine becomes dynamic?"
Ask your ISP.

 

[Jeff Liebermann]

On 28 Sep 2005 07:52:23 -0700, (e-mail address removed) wrote:

5 newsgroups crossposted. I guess a shotgun is more effective at
target practice.

I want to ask who assigns the IP address to a machine that connects to
the Internet? The ISP, the network card (i.e. MAC address??), or the
router?

The limited supply of IP addresses were originally assigned by the net
gods. Through a covenant with various governments, the IANA was
empowered to distribute these IP's to the various ISP's in accordance
to an ordeal process which includes much petitioning, grovelling,
begging, and the inscription of forms. Your ISP then delivers unto
the multitudes a single IP address, which you are entitled to borrow
for the duration of your connection. Be thankful that they even have
IP's to give out.

It seems like my IP address is fixed everytime connected to the
Internet,

Better to have it fixed than to have it broken.

it seems very unsecure because it allows hackers track the
computers more easily.

No problem. Dive into your router and change the MAC address on the
"Clone MAC address" page. You can select almost any number you find
useful except that of the ISP gateway. Every time your change your
MAC address, disconnect, and reconnect, you'll get a new IP address.
Of course, this will drive your ISP's logs up the wall and suggest
that you're doing something evil and nefarious such as trying to hide
your tracks as a spammist. It will also cause him to perhaps run out
of available IP's as your previous IP addresses won't expire for quite
some time. Be prepared to get yelled at by your ISP.

I thought the IP address should be dynamic, and each time when we
connect to the Internet should have different IP address.

It can be. Some ISP's do that. However, it's usually not because
they are trying to enhance your security. It's because they simply
don't have enough IP's to handle all their customers and recycle them
often to other users. The limiting factor is the duration of the ARP
cache, which maps your MAC address to your IP address. You can see it
in Windoze if you run:
Start -> Run -> cmd<enter>
arp -a
Ping a few boxes and watch the numbers appear and disappear. To keep
the IP's stable, most ISP's run their ARP cache timeout at least 24
hours or more.

 

[James Knott]

I want to ask who assigns the IP address to a machine that connects to
the Internet? The ISP, the network card (i.e. MAC address??), or the
router?

It seems like my IP address is fixed everytime connected to the
Internet, it seems very unsecure because it allows hackers track the
computers more easily.

I thought the IP address should be dynamic, and each time when we
connect to the Internet should have different IP address.

Is there a way that makes the IP address in my machine becomes dynamic?

The IP address is assigned by the ISP. Normally, with DHCP, you "own" the
address for the duration of the lease time. Part way through the lease,
your computer (or router) will attempt to renew the address. This means
that as long as you stay connected, you will likely retain the same
address. Your computer caches the address, so that if you turn it off and
later, back on, it will request the same address, if available. You might
be able to get a new address, if you release the IP and then get another
address, however that may not always work, as your ISP may also cache the
IP & MAC address pair, for at least the duration of the lease. If that's
the case, your only options for forcing a change, is to change the MAC
address of your hardware, or leave your equipment turned off long enough
for the lease to expire and the address be assigned to someone else.

 

[James Knott]

No problem. Dive into your router and change the MAC address on the
"Clone MAC address" page. You can select almost any number you find
useful except that of the ISP gateway.

Or one that's in use by someone else connected to the same ISP. Duplicate
MACs are a no-no.

 

[Steven L Umbach]

Your ISP assigns it and it is not unusual to have the same IP for a long
time. Protect your computer/network with a properly configured firewall and
don't worry about it. Then take other steps as outlined in the link below
to protect your network as they are all important no matter what IP you have
or even if it changed daily. --- Steve

http://www.microsoft.com/athome/security/protect/windowsxpsp2/Default.mspx
--- Protect your PC tips from Microsoft.

 

[James Knott]

--- Protect your PC tips from Microsoft.

Tip #1 Forget Windows. ;-)

 

[Michael Heiming]

Your ISP assigns it and it is not unusual to have the same IP for a long
time. Protect your computer/network with a properly configured firewall and
Ack.

[..]

http://www.microsoft.com/athome/security/protect/windowsxpsp2/Default.mspx
--- Protect your PC tips from Microsoft.

Shouldn't that be, protect your PC from Microsoft? Good idea to
enhance security.

 

[Mike Preston]

Nice crossposting!

Your ISP is assigning your Internet IP Address - You need a static
address if you are:
Hosting a mailserver
Hosting a website
Providing Dialin Access (VPN)

No, you don't. no-ip, dyndns and similar services allow you to do all
of the above with dynamic IPs.

mike

 

[N. Miller]

No problem. Dive into your router and change the MAC address on the
"Clone MAC address" page. You can select almost any number you find
useful except that of the ISP gateway. Every time your change your
MAC address, disconnect, and reconnect, you'll get a new IP address.

According to his headers:

NNTP-Posting-Host: 69.107.32.120

According to Sam Spade:
=================================================================
09/28/05 15:14:15 dns 69.107.32.120
nslookup 69.107.32.120
Canonical name: adsl-69-107-32-120.dsl.pltn13.pacbell.net
Addresses:
69.107.32.120
=================================================================

That is very likely a dynamic IP address pool; unless it is an old,
grandfathered PacBell static IP address, it should, eventually, change. Or,
the OP could just shut down his DSL modem for about five, or ten minutes.
Almost certainly, he will get a new IP address when he fires things up
again. SBC does not associate IP address to MAC address for its dynamic IP
address pool (they use PPPoE for authentication to the network), so
changing the MAC address is a futile exercise.

 

[David Schwartz]

No, you don't. no-ip, dyndns and similar services allow you to do all
of the above with dynamic IPs.

For hosting a mail server?! Surely you are joking.

DS

 

[N. Miller]

I want to ask who assigns the IP address to a machine that connects to
the Internet? The ISP, the network card (i.e. MAC address??), or the
router?

The ISP controls the issuing of IP addresses.

It seems like my IP address is fixed everytime connected to the
Internet, it seems very unsecure because it allows hackers track the
computers more easily.

A fixed IP address is not less secure than a dynamic IP address; indeed,
dynamic IP addresses are the norm for consumer accounts, and "crackers"
(the malicious variety of hacker) have devised neat little applications
which can determine the IP address of an Internet connection, then phone
home. So malicious actors can track a particular computer on the Internet,
even if its IP address changes every minute.

I thought the IP address should be dynamic, and each time when we
connect to the Internet should have different IP address.

Do you have the standard SBC Express DSL package? If so, you do have a
dynamic IP address.

Is there a way that makes the IP address in my machine becomes dynamic?

I believe the standard IP address lease time for SBC DHCP addresses
(technically, these are PPP IP addresses, but they still have a DHCP lease
time) is about seven days. At about three and a half days, your router, or
modem will request a renewal; it will usually get the same IP address.

I have had the same SBC IP address for a long as eight days (196 hours). I
have also seen my SBC IP address change three times in one day. The best
way to ensure a new IP address lease from SBC is to shut down the PPPoE
device for a minimum of five minutes. That is, usually, long enough for
another SBC customer to pull the IP address you just gave up by shutting
down. When you next power up, you should see a new IP address.

Do you know which of your devices initiates the PPPoE session? When I was
running a Westell WireSpeed 36R516 ADSL modem, my router initiated the
PPPoE session, so I would reboot the router for a new IP address. I am now
running a SpeedStream 4100 ADSL modem, with the PPPoE session initiated
from the modem, so I would shut down the modem. If you are using a PPPoE
connection manager on the computer, you would need to shut down that PPPoE
manager.

OTOH, I don't see much point in forcing an IP address change, and I do have
an application running which requires having a known IP address on the
Internet, so I prefer not to change IP address any more often than
necessary; when it does change, it becomes necessary to change my DNS
settings for my domain.

 

[Jeff Liebermann]

Or one that's in use by someone else connected to the same ISP. Duplicate
MACs are a no-no.

True. However, it happens often enough that many ISP's use the MAC
address for RADIUS authentication. If the MAC address is duplicated,
authentication fails. However, you're right. It will cause havoc if
the user picks a duplicated address. The chances of that happening
are small, but possible.




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# 831.336.2558 voice Skype: JeffLiebermann
# http://www.LearnByDestroying.com AE6KS
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# (e-mail address removed)-cruz.ca.us
# (e-mail address removed)

 

[Mike Preston]

For hosting a mail server?! Surely you are joking.

Not in the slightest. I've had 100% uptime (where I haven't disabled
the server for my own purposes and acquired a new dynamic IP in the
process, or changed my non-dynamic IP) for over 3 years. Mail server
and all. As long as the Mx records are properly recorded, everything
goes through. I had to fight a bit with AOL, but even they relented.

mike

 

[Llanzlan Klazmon]

(e-mail address removed) (Mike Preston) wrote in

No, you don't. no-ip, dyndns and similar services allow you to do all
of the above with dynamic IPs.

True but that's a bit of a kludge.

Klazmon.

 

[James Knott]

However, you're right. It will cause havoc if
the user picks a duplicated address. The chances of that happening
are small, but possible.

Of course it's possible. There are only 2^48 combinations to play
with. ;-)

 

[Mike Preston]

(e-mail address removed) (Mike Preston) wrote in


True but that's a bit of a kludge.

Now that I agree with. Definitely a bit of a kludge.

mike

 

[Floyd L. Davidson]

On 29 Sep 2005 13:13:52 +1200, Llanzlan Klazmon


Now that I agree with. Definitely a bit of a kludge.

Can't agree with that. It works quite well, and the appearance
of that functionality was a *huge* relief.

Remember when changing anything with your DNS, unless you were
far enough up the food chain to be running your own DNS server
for the entire Internet (not just your own network), meant that
changing anything took a *week* to be effective? That was true
even for ISP's, and was a real pain.

Now, my domain resolves to whatever I want to it, and can change
in less than two minutes (and it will take me longer than that
to remember how to do it manually).