Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations SkipVought on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Changing IP range as smoothly as possible.

Status
Not open for further replies.
Phil79

Phil79

Technical User
Jun 5, 2002
64
0
0
GB
Hi guys (ands gals)

We are trying to change the IP range of our network to a private one. At the moment (and I have no idea why it was set up this way), our computers use 192.0.0.*, which we would like to change over to 192.168.*.*. I am assuming that given a subnet mask of 255.0.0.0, workstations in both the old and new ranges would be able to function together on the network. Is this correct? If not, any helpful advice would be gratefully accepted. The reason for doing this is that we can gradually change over non-DHCP compliant IP devices such as HP Jet Direct boxes and our AS400 server in our own time and everything will work on the network together.

Thanks in advance
Phil
 
Sort by date Sort by votes
I can't see a reason why it's not possible. (192.0.0.1 - 192.255.255.254) /8 or 255.0.0.0 subnet mask.
 
Upvote 0 Downvote
Yes based on the subnet you can set up anything in the 192.0.0.0 range
However, if you choose to subnet you will need to make sure that you assign all network host in that same range unless setting up different networks. Then that is another issue that could be asked later...I do not want to rant...sorry!
 
Upvote 0 Downvote
Well that depends on what your goal is. If you are trying to go to a 192.168.*.* network ID with a subnet mask of /24 (255.255.255.0), then you are going to wind up back where you started.

Do you currently have a subnet mask of /8 (255.0.0.0)?

Is this a routed environment with multipile networks?


bob





I know what I know and that's all I know.
 
Upvote 0 Downvote
Who...
this ip range is private and it does not matter what block size they use. They can use the /8 or a /30 it does not matter because it will never get routed outside the network.

As long as they keep within each subnet they are breaking up, or if they are going to just open the entire block, they need to make sure they route together within themselves.
 
Upvote 0 Downvote
Thanks everyone.

We are currently using 192.0.0.*/24 on the site that I am at. We would like to chage the range over to 192.168.0.*/24.

We have two networks on two differant sites which will be joined up in the future. One will be 192.168.1.*/24 and the other will be 192.168.0.*/24 in anticipation of them eventually being joined up by a router of some sort.

The big problem is doing it with as little inconvenience as possible. The networks are fairly simple. The one in question is a simple network in one building with a network and a combination router/firewall device as it's gateway. It's running 2 Windows 2000 servers with DNS + DHCP. The potential problems are as follows:

1. We run an IBM AS400 system which is absolutely vital to the running of the business. It runs over TCP/IP through client emulation software on the workstations. We cannot remove access to this or at least 50% of people in the office will be unable to do their job.

2. We have one other non Windows device on the network, a Quantum Snapserver running Linux. I have absolutely no understanding of Linux at all, I just thought it may be a pertinant point.

3. We have a lot of workgroup printers running on JetDirect boxes. Changing the IP address of every one of these will result in none of the users being able to print to them.

Is any more info required?
 
Upvote 0 Downvote
Equipment in this case does not matter.
What does matter is the IP Blocks you are using.

What is currently assigned now?

Are you subnetted currently out of the /8 block?

If you change IP's to a more specific block, such as the 168.0.* and 168.1.* both /24 then you will need to make sure that your DHCP server, and all other statically mapped machines are in this same blocks you are using.

If you are currently running in this range, but under the /8 network, then there is no problem to be more specific in your class assignment.
 
Upvote 0 Downvote
Thanks guys, but, to be correct... An address is only private as long as you stop from going out to the internet.
192.168.0.0/24 is a private address range. 192.0.0.0, and various blocks within the 192 range, is not. Check out this link:

"192/8 May 93 Various Registries"

Supperneting is a great thing, but can have its drawback if you are not sure of what you are doing.

As for your solution to changing ip address ranges, you can easily assign multiple addresses to a router or firewall interface to have it route an old and new ip range; if you have the capability. Check your router IOS. By adding the new ip address you can take your time and move over what you want when you want.

bob


I know what I know and that's all I know.
 
Upvote 0 Downvote
Case in point:

C:\>ping
Pinging namweb14.sugar-land.nam.slb.com [192.23.100.137] with 32 bytes of data:


Notice the address? You may be blocking your users from getting to other sites.


bob

I know what I know and that's all I know.
 
Upvote 0 Downvote
Who...

192.168 is the private block...no one is refuting that.
In this case and the ip range provided we were simply telling him that his block is private?!?!? what case are you trying to point out?
 
Upvote 0 Downvote
I take the point that Whoheard is making though. Part of the reason that we are doing this is that two "fairly important" websites hp.com and adobe.com are all inaccessible to us...
 
Upvote 0 Downvote
nyy1023,

The point is exactly what Phil79 understands. His subnet mask of 255.0.0.0 was another persons mistake which he wants to correct. The wrong subnet mask is preventing him from accessing other public 192 IP's.

Phil79,

If my other suggestion of multiple IP on an interface will not work, then take a look at the range of node IP's on the network. Find out the range of numbers used in the 2nd octet (0.*.0.0). If these numbers are fairly close together, perhaps the scope can be reduced to a smaller subnet mask like 255.252.0.0, or 255.254.0.0. Instead of a network ID of 192.0.0.0 you would get something like 192.164.0.0. By doing this you would:

1. get back internet access to those sites previously not accessible.

2. be in a better position to realign the newtwork.

BTY...
It really does not matter what subnet mask the user has. The subnet mask on the router determines who is accessible on that subnet.


bob

I know what I know and that's all I know. What I don't know I will ask.
 
Upvote 0 Downvote
Erm, not really. The subnet mask is currently 255.255.255.0. The issue is that I want to change the mask to 255.0.0.0 temporarily so that we can change over IP devices which do not use DHCP in our own time, and users who have already been changed to 192.168.... can still access them.
 
Upvote 0 Downvote
OK. On the router interface, depending on the number of subnets you currently have, you need to change the mask to > 255.255.255.0. Like 255.255.252.0, or 255.255.254.0. You may need to go lower depending on the number of subnets.

Remember, the router is king and knows where to find all th ip networks. This will work like a router on a stick.

bob

I know what I know and that's all I know. What I don't know I will ask.
 
Upvote 0 Downvote
There is currently one subnet involved which we have a problem with. I was talking about changing the subnet mask on the workstations using DHCP. The router is not really part of the equation yet as the two networks we have are not yet joined. The one off site is already IP addressed correctly, but the one where I am has the non private address range and a subnet mask of 255.255.255.0.
 
Upvote 0 Downvote
The same rule apply's. As long as you have all IP's starting with 192.168. you can set the router subnet mask to 255.255.0.0 and all users will still be able to communicate.

Hope this helps.


bob

I know what I know and that's all I know. What I don't know I will ask.
 
Upvote 0 Downvote
I think you may be misunderstanding what I mean. I need computers with 192.168.... to be able to communicate with IP devices in the 192.0.0.... range and was asking if changing the subnet mask of everything on the network to 255.0.0.0 would allow this to be so.
 
Upvote 0 Downvote
My bad. Then yes it would work. But don't forget about the public addresses that you will not be able to access.


bob

I know what I know and that's all I know. What I don't know I will ask.
 
Upvote 0 Downvote
Can anyone explain how you calculate the subnetsblock. /8 and /24 and /30 so on. And wich of them will work with eachother without any router.

Thank's
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

dl12345
  • Locked
  • Question
IPV6 related issue on bind 9.16.1 on Ubuntu 20.04
Replies
1
Views
2K
dl12345
dl12345
ramaning
  • Locked
  • Question
BIND DNSs Has Pointed to Diff IP Addresses.
Replies
1
Views
121
unixfreak
unixfreak
TheAceMan1
  • Locked
  • Question
Same IP Address ... Different Web Sites ... How? 1
Replies
4
Views
69
TheAceMan1
TheAceMan1
kidSmart
  • Locked
  • Question
Find IP Addresses of Target 1
Replies
1
Views
38
iggsterman
iggsterman
mdcr1
  • Locked
  • Question
Certain clients on Windows 2003 domain get assigned to Network 2, IP address of 192.168.0.255?
Replies
4
Views
34
VinceWhirlwind
VinceWhirlwind

Part and Inventory Search

Sponsor

Back
Top