Solved

/24 network running out of free IP addresses

Posted on 2014-02-09
6
414 Views
Last Modified: 2014-02-12
Hi Experts,

Our 192.168.0.0 /24 network is running out of IP addresses.

What's the easiest way to get more addresses without changing the whole class (to 10.0.0.0 /8 or similar).

Can I just change the network mask on all devices and servers to /22?
That seems like the easiest way to go, I just wonder if that will work.

Please notice that we have a SAN network on 192.168.100.0 /24 - I want to make sure it won't be affected.

Let me know what you think.
0
Comment
Question by:itorana
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 3

Assisted Solution

by:computication
computication earned 250 total points
ID: 39846443
The easiest way to go is to change your network to a /23. Or /22 if you feel, you need the extra IP addresses. This will not interfere with your SAN.

You could also go for VLAN separation but that requires more work and layer 3 switches.

Kind regards,

M
0
 
LVL 8

Expert Comment

by:Surrano
ID: 39846670
With these restrictions you can go as high as /18 (192.168.0.0-63.255) but I'd say that there must be something strange in your network topology. Slicing into smaller subnets would likely improve routing performance as well, even if you need to add another router.

Try to reorganise the IP addresses into subnets of <256 by means of
- physical topology (e.g. server room A = 1.0/24, server room B = 2.0/24
- logical topology (e.g. finance = 1.0/24, production = 2.0/24, development = 3.0/24)
and have common networking like the main route towards the external world is 0.0/24

Even if you have some (or even hundreds of) virtual interfaces on same piece of cable you could easily achieve different subnets used by different virtual interfaces on same physical interface. E.g. if you have a virtualisation server with 200 vms and 5 virtual interfaces each (o&m, app, db, cluster interconnect, backup) then you can configure the 200 O&M interfaces to use 1.0/24, the 200 app interfaces to use 2.0/24 etc.

Just make sure that the routers they are connected to also receive messages on all of these subnets.
0
 

Author Comment

by:itorana
ID: 39846677
Hi Surrano,

Thanks for detailed reply! We don't have any routers or even layer 3 switches to do routing. Could that cause problems in the future if we just changed the mask to /23? (500 addresses is more than enough).
0
Flexible connectivity for any environment

The KE6900 series can extend and deploy computers with high definition displays across multiple stations in a variety of applications that suit any environment. Expand computer use to stations across multiple rooms with dynamic access.

 
LVL 17

Expert Comment

by:pergr
ID: 39846726
I recommend changing to /23.
You will keep using the same default gateway as before.

Generally, just change the /23 in your DHCP settings, and do not worry too much about migration. Catch up with all statically configured devices afterwards.
0
 
LVL 8

Accepted Solution

by:
Surrano earned 250 total points
ID: 39846761
subnets should work with plain old "dumb" hubs or switches as well. Those that are so dumb that they don't know anything about netmasks :)

as a gradual approach, if you change the netmask to /23 or even wider then you can proactively distribute the static IP addresses and define the dynamic ranges in a way that later on, if you think it's worth the effort, you can change from one wide netmask to several narrower ones. But the simplest solution for the time being is indeed to simply change the netmask but make sure you do it everywhere.
0
 
LVL 26

Expert Comment

by:Soulja
ID: 39847434
What type of device is providing the routing for your network? You can just go to that interface and configure a secondary subnet on it.  This way you don't have to make any changes to your existing devices.
0

Featured Post

NEW Veeam Agent for Microsoft Windows

Backup and recover physical and cloud-based servers and workstations, as well as endpoint devices that belong to remote users. Avoid downtime and data loss quickly and easily for Windows-based physical or public cloud-based workloads!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
help Skype for Business keeps dropping 7 31
Can't access router with user and pass 10 74
Network adapter for Windows 7 9 50
Application timeout 4 39
Resolve DNS query failed errors for Exchange
I had an issue with InstallShield not being able to use Computer Browser service on Windows Server 2012. Here is the solution I found.
Viewers will learn how to connect to a wireless network using the network security key. They will also learn how to access the IP address and DNS server for connections that must be done manually. After setting up a router, find the network security…
Internet Business Fax to Email Made Easy - With  eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, f…

735 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question