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
Solved

subnet_extend_of_vlan

Posted on 2012-03-15
6
323 Views
Last Modified: 2012-03-30
Hi,

At the moment we have a below Vlan.

int vlan20
ip address 10.12.13.1 255.255.255.0
no shut


now we do not left with the much free address on this vlan. So we are planning to subnet the Vlan from /24 to /23

In order to do and achieve this what and where the changes needs to be done.

Thanks
0
Comment
Question by:network-guru
6 Comments
 
LVL 1

Expert Comment

by:vinay1285
ID: 37726560
You would then change the subnet mask used while configuring vlan. I would say it looks like

int vlan20
ip address 10.12.13.1 255.255.254.0
no shut
0
 

Author Comment

by:network-guru
ID: 37726614
Thats fine.
My question is that apart from this where i have to make the change.

for example as earlier the Vlan10 ip address and subnet is 10.12.13.1 255.255.255.0
and this is the gateway for my LAN.

So on if there is any server in that subnet will be having the Gateway IP as 10.12.13.1 and the mask information will be 255.255.255.0

anyhow it will work even if i will not change its subnet from 255.255.255.0 to 255.255.254.0 but it will work from the local LAN only. From outside where ever the routing was done it was learning as /24 so i need to get the routing change done as well.

so that from wherever it was getting learned as /24 will learn as /23 and to make it fullproof and make sure that it will work fine. i think it is a good practice to change the sunet as well on all host where to /23

Please correct if i am wrong.
0
 
LVL 3

Expert Comment

by:rafter81
ID: 37728340
Depends if you are using static routing or OSPF/RIP etc.  You just need to change the IP address/subnet of the interface the gateway address is assigned on (10.12.13.1).  If you do this and not using static routing then the new subnet will be learned and entered in the routing table.  If using static routes you need to look on your switches/routers for these route definitions.

Don't forget if your using DHCP you need to change the scope/subnet.  DNS reserve lookup zones and if using AD, Sites subnets will need updating too.
0
Resolve Critical IT Incidents Fast

If your data, services or processes become compromised, your organization can suffer damage in just minutes and how fast you communicate during a major IT incident is everything. Learn how to immediately identify incidents & best practices to resolve them quickly and effectively.

 

Author Comment

by:network-guru
ID: 37730970
Do i not need to change the subnet mask information from /24 to /23 on each host where ever the static IP was configured on the host/servers.

Thanks
0
 
LVL 3

Expert Comment

by:rafter81
ID: 37731491
Yes, if you are not using DHCP and only static I addresses, the subnet mask should be changed on the hosts as well
0
 
LVL 29

Accepted Solution

by:
pwindell earned 500 total points
ID: 37739220
Add a Router
Add a new segment.

Do not roll that mask to /23.  That creates a broadcast domain of 510 which is too big to be efficient.  Degradation begins around 300.
0

Featured Post

NFR key for Veeam Backup for Microsoft Office 365

Veeam is happy to provide a free NFR license (for 1 year, up to 10 users). This license allows for the non‑production use of Veeam Backup for Microsoft Office 365 in your home lab without any feature limitations.

Question has a verified solution.

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

Suggested Solutions

Is your computer hacked? learn how to detect and delete malware in your PC
David Varnum recently wrote up his impressions of PRTG, based on a presentation by my colleague Christian at Tech Field Day at VMworld in Barcelona. Thanks David, for your detailed and honest evaluation!
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…

839 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