Can I change my IP address?

[TommyHolly]

Is that possible?

I have a Cable Modem attached to a Router and I am running off of that. Can I change my IP Address by maybe unplugging my CAT5 cable and plugging into a different router port or can I do it through my PC?

Also, how do I see what IP I am running now?

Thanks guys.

[((jjerkY))]

you can reset your modem (unplug for a few mins.) your ip will change automatically

[Kendan]

Which IP do you want to change? The DHCP IP of your rig (yes you can change it) or your IP given to you by your ISP? If the latter is the case you could have a static IP or Not. If it is static you will have to call the isp to see if they will change it for you. If it is not static then turning off the modem and turning it back on should give you a fresh IP. To see what your inner ip is go to a command line and type ipconfig /all
to find out your outside IP go to www.whatismyip.com


Good luck:D

[nil_esh]

This depends on your ISP and how they have things setup. Usually, unplugging the modem works, though sometimes you may get the same IP.

As for finding out your IP address, you can use one of those sites, such as http://www.whatismyipaddress.com/

But I like to use a PHP script that I put up in my own webspace:

<?php
$ipaddress = getenv(REMOTE_ADDR);
echo($ipaddress );
?>

[TommyHolly]

If it's an outside IP address, then can I change it?

[diggingforgold]

Yeah, unplug your cable modem for a few seconds- that should do the trick unless you are paying for a static ip address. Most cable companies switch over your IP after about 3 days (at least thats what mine does).

Your internal ip (anything that comes after your router) is usually static. If you swap your cat5's cord to another port on the router, it will only change your internal ip. But the one that people see on the internet is the ip address of your router- which can be reset by powering off your cable modem (in most cases).

[bdf24]

Yeah but it does not work all the time. My ISP assigns a static IP address. I cannot change it. I'd have to call my ISP.

[bluestreakLB]

Originally posted by bdf24
Yeah but it does not work all the time. My ISP assigns a static IP address. I cannot change it. I'd have to call my ISP.

My god i was hoping someone would say this :D

[jajmon]

Originally posted by TommyHolly
Is that possible?

I have a Cable Modem attached to a Router and I am running off of that. Can I change my IP Address by maybe unplugging my CAT5 cable and plugging into a different router port or can I do it through my PC?

Also, how do I see what IP I am running now?

Thanks guys.

1> Why do you want to change your external IP address?
2> To find out what your external IP address is, open your browser and go the admin screen for your
router, usually 192.168.xxx.xxx, (this depends on your router) log in and your first screen should
should display what your wan/external address is.
3> If your ISP assigned you a static address, and you want it changed, you have to call them
4> If your ISP assigns you a 'random' address (DHCP, which most do) then unplugging your modem
for 30 min or so 'may' give you a different address. I have had the same DHCP assigned address
for 9 months. I have my router set to 'renew ip forever' . By default, dhcp nodes, will always request
the same address that was assigned to them, and if available, the dhcp server will honor that request

[Kendan]

Originally posted by bluestreakLB


My god i was hoping someone would say this :D

I said it first:p

[nil_esh]

Originally posted by TommyHolly
If it's an outside IP address, then can I change it?

I guess the short answer is: no.

Only your ISP can control what your IP address is, so you'll have to contact them for any changes. Or you can try the unplug the modem trick and try to get a new [random] IP address, but it may not work.

[TommyHolly]

Jajmon,

(1) I want to change it because I got banned from a Wolfenstein Enemy Territory server room. (The adim was a real jackass and was cheating and I complained) Some people are able to log back on within 2 minutes even when they get banned...I wanna know how to do that.

As far as the rest, thanks. I think I understand most of what you guys said... (except what a DHCP is?) I'll unplug it and the re plug it in.

[Smokeys]

Originally posted by TommyHolly
Jajmon,

(1) I want to change it because I got banned from a Wolfenstein Enemy Territory server room. (The adim was a real jackass and was cheating and I complained) Some people are able to log back on within 2 minutes even when they get banned...I wanna know how to do that.


You should know that asking on how to bypass bans (even one placed on an ET server) is agaist the forum rules.

There are plenty of other ET servers avaiable, I suggest moving on...

[jajmon]

quote:
Originally posted by TommyHolly
Jajmon,

(1) I want to change it because I got banned from a Wolfenstein Enemy Territory server room. (The adim was a real jackass and was cheating and I complained) Some people are able to log back on within 2 minutes even when they get banned...I wanna know how to do that.


You should know that asking on how to bypass bans (even one placed on an ET server) is agaist the forum rules.

There are plenty of other ET servers avaiable, I suggest moving on...


Very good point , I was curious as to why one wanted to change their ext address and that is why I asked. Now we know.

[FunkDaMonkMan]

In that cae, you are going to have to change your external IP. That cannot be done in 2 min if you have cable. Those people you see, probably have dial-up, and they can just reconnect to get a new ip address.

[mbentley]

just for future reference, with my cable modem, i can unplug it for a few hours and it will remain the same ip address and i certainly know it is not static. it seems that all the ip addresses are recycled every couple weeks though...

the funny thing is that basically if my cable modem stays connected for a long time, it will keep the same ip address until it is reset by power loss sometime down the road...

[hkgonra]

I have had the same ip for at least a year ,my cable service has to be down or my modem unplugged for a few day to reset it.

[Glaze132]

I know I am able to change my IP address to anything I want as long as it is in the cable modems subnet i.e. 68.108.54.xxx and as long as I change the last octet of the IP and it is not in use by another user I can use it. So before you change it to a specific IP address make sure you copy down the default gateway, dns, subnet mask, and the first three octets of the actual IP address and then fill in the x's with your own numbers preferably the ones you were not using before. I am talking about being directly connected to the cable modem and not just your LAN/WAN. Cox is my provider and allows us as far as I know to do this.

[UnseenMenace]

The assumption that changing your IP address will get you around a ban may actually be incorrect as there are many other ways possible in which to ban someone from service

[PAWO]

I use comcast, and my IP address hasn't changed in a little less than a year, amazing part is, we lost power for 4 days after an ice storm in April, but the IP was the same when the power came on and router/modem restarted, but about a month later, we lost power about 5 seconds one morning for no obvious reason, and the IP address changed to what it is now. I have also found that if you know all of the required info, such as Subnet, Gateway, and the DNS servers, you can force your own static IP and it will work fine and will never change because the router ignores DHCP when set to static. The same works on our internal LAN, some pc's (our servers) I have set to Static even though they are in the DHCP range, and all works fine, the router just skips over the static ones when assigning IP's to the other pc's.

[jajmon]

Originally posted by PAWO
I use comcast, and my IP address hasn't changed in a little less than a year, amazing part is, we lost power for 4 days after an ice storm in April, but the IP was the same when the power came on and router/modem restarted, but about a month later, we lost power about 5 seconds one morning for no obvious reason, and the IP address changed to what it is now. I have also found that if you know all of the required info, such as Subnet, Gateway, and the DNS servers, you can force your own static IP and it will work fine and will never change because the router ignores DHCP when set to static. The same works on our internal LAN, some pc's (our servers) I have set to Static even though they are in the DHCP range, and all works fine, the router just skips over the static ones when assigning IP's to the other pc's.

DHCP servers and clients don't work that way.

The dhcp server knows what it can give out for addresses and keeps track of those. It doesn't know about statically assigned addresses and 'skips' over them as you say. If for some reason a new dhcp client asks for an address, the server 'could' give out an addy that you have assigned as static. This would cause problems.
The dhcp client, when first coming online, blindly broadcasts for an address, the dhcp server, hears the request, and gives an address in it's assigned range that hasn't been given out before. The dhcp client, after been given an address, no longer does a blind broadcast request for an address, it will request the same address it was given the first time. When the dhcp server hears that request, it looks to see if that addy has been assigned, if not, it will honor the request from the client.
You are probably ok in your environement,because it it small, and the dhcp protocal for server/client has already been established. If you add more to your network, a new client could receive an addy that you have assigned as static. You should really assign static ip's outside of the dhcp server's range to avoid potential problems. I work in a large corporate environement. We have had users for whatever reason think they need a static IP, will ping an address and if there is no reply, they take it. This has caused problems in many different ways. First off they don't understand the network with it's subneting and gateways. They will assign a static IP for a pc, when the address they ping is on a different subnet, with a different gateway. (not knowing what subnet they are on) Sometimes it has happenned, that they will assign an addy for a production host ( it didn't reply from a ping because it was down, for a reboot, maintenance. etc, so let's use that address, it's available right- no ping. The 'real' production host for that address comes back online, nobody can get to it because of an IP conlict and h*ll breaks loose)) They then call the help desk, because they can't get to their pc/server/host/whatever - go figure

The following is an 'excerpt' from this site, ftp://ftp.isi.edu/in-notes/rfc2131.txt, that I have explained above in simpler terms.

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type of hardware to accommodate possible duplication of hardware
addresses resulting from bit-ordering problems in a mixed-media,
bridged network) allowing for serial or concurrent reuse of a
hardware address on different subnets, and for hardware addresses
that may not be globally unique. Alternately, the key might be the
pair (IP-subnet-number, hostname), allowing the server to assign
parameters intelligently to a DHCP client that has been moved to a
different subnet or has changed hardware addresses (perhaps because
the network interface failed and was replaced). The protocol defines
that the key will be (IP-subnet-number, hardware-address) unless the
client explicitly supplies an identifier using the 'client
identifier' option. A client can query the DHCP service to
retrieve its configuration parameters. The client interface to the
configuration parameters repository consists of protocol messages to
request configuration parameters and responses from the server
carrying the configuration parameters.

2.2 Dynamic allocation of network addresses

The second service provided by DHCP is the allocation of temporary or
permanent network (IP) addresses to clients. The basic mechanism for
the dynamic allocation of network addresses is simple: a client
requests the use of an address for some period of time. The
allocation mechanism (the collection of DHCP servers) guarantees not
to reallocate that address within the requested time and attempts to
return the same network address each time the client requests an
address. In this document, the period over which a network address
is allocated to a client is referred to as a "lease" [11]. The
client may extend its lease with subsequent requests. The client may
issue a message to release the address back to the server when the
client no longer needs the address. The client may ask for a
permanent assignment by asking for an infinite lease. Even when
assigning "permanent" addresses, a server may choose to give out
lengthy but non-infinite leases to allow detection of the fact that
the client has been retired.

In some environments it will be necessary to reassign network
addresses due to exhaustion of available addresses. In such
environments, the allocation mechanism will reuse addresses whose
lease has expired. The server should use whatever information is
available in the configuration information repository to choose an
address to reuse. For example, the server may choose the least
recently assigned address. As a consistency check, the allocating
server SHOULD probe the reused address before allocating the address,
e.g., with an ICMP echo request, and the client SHOULD probe the
newly received address, e.g., with ARP.





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3. The Client-Server Protocol

DHCP uses the BOOTP message format defined in RFC 951 and given in
table 1 and figure 1. The 'op' field of each DHCP message sent from
a client to a server contains BOOTREQUEST. BOOTREPLY is used in the
'op' field of each DHCP message sent from a server to a client.

The first four octets of the 'options' field of the DHCP message
contain the (decimal) values 99, 130, 83 and 99, respectively (this
is the same magic cookie as is defined in RFC 1497 [17]). The
remainder of the 'options' field consists of a list of tagged
parameters that are called "options". All of the "vendor extensions"
listed in RFC 1497 are also DHCP options. RFC 1533 gives the
complete set of options defined for use with DHCP.

Several options have been defined so far. One particular option -
the "DHCP message type" option - must be included in every DHCP
message. This option defines the "type" of the DHCP message.
Additional options may be allowed, required, or not allowed,
depending on the DHCP message type.

Throughout this document, DHCP messages that include a 'DHCP message
type' option will be referred to by the type of the message; e.g., a
DHCP message with 'DHCP message type' option type 1 will be referred
to as a "DHCPDISCOVER" message.

3.1 Client-server interaction - allocating a network address

The following summary of the protocol exchanges between clients and
servers refers to the DHCP messages described in table 2. The
timeline diagram in figure 3 shows the timing relationships in a
typical client-server interaction. If the client already knows its
address, some steps may be omitted; this abbreviated interaction is
described in section 3.2.

1. The client broadcasts a DHCPDISCOVER message on its local physical
subnet. The DHCPDISCOVER message MAY include options that suggest
values for the network address and lease duration. BOOTP relay
agents may pass the message on to DHCP servers not on the same
physical subnet.

2. Each server may respond with a DHCPOFFER message that includes an
available network address in the 'yiaddr' field (and other
configuration parameters in DHCP options). Servers need not
reserve the offered network address, although the protocol will
work more efficiently if the server avoids allocating the offered
network address to another client. When allocating a new address,
servers SHOULD check that the offered network address is not



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already in use; e.g., the server may probe the offered address
with an ICMP Echo Request. Servers SHOULD be implemented so that
network administrators MAY choose to disable probes of newly
allocated addresses. The server transmits the DHCPOFFER message
to the client, using the BOOTP relay agent if necessary.

Message Use
------- ---

DHCPDISCOVER - Client broadcast to locate available servers.

DHCPOFFER - Server to client in response to DHCPDISCOVER with
offer of configuration parameters.

DHCPREQUEST - Client message to servers either (a) requesting
offered parameters from one server and implicitly
declining offers from all others, (b) confirming
correctness of previously allocated address after,
e.g., system reboot, or (c) extending the lease on a
particular network address.

DHCPACK - Server to client with configuration parameters,
including committed network address.

DHCPNAK - Server to client indicating client's notion of network
address is incorrect (e.g., client has moved to new
subnet) or client's lease as expired

DHCPDECLINE - Client to server indicating network address is already
in use.

DHCPRELEASE - Client to server relinquishing network address and
cancelling remaining lease.

DHCPINFORM - Client to server, asking only for local configuration
parameters; client already has externally configured
network address.