We help IT Professionals succeed at work.

Subnet full

533 Views
Last Modified: 2010-04-10
Hi There,

I have a subnet at a site that is just about full. Its a C class (Eg 192.168.0.0/255.255.255.0).

I have servers, workstations and printers in this subnet. I have thought of splitting servers into their own subnet (via a VLAN) but am worried about the performance implications of this. If i have to do inter VLAN routing will this reduce the bandwidth available (and increase latency) for the workstations to access servers?

The other option is to stretch out the subnet mask for the existing network (Eg. 192.168.0.0/255.255.255.248) but im already using the above network at another site (Eg 192.168.1.0/255.255.255.0).

Any thoughts?



Comment
Watch Question

Commented:
Vlan's will be the easiest solution if you have a good layer 3 switch to do the routing for you.  Bandwidth latency will be dependant on the hardware.  I have not experienced latency on HP and Cisco, 3Com.
Commented:
Unlock this solution and get a sample of our free trial.
(No credit card required)
UNLOCK SOLUTION

Commented:
VLAN routing is another task your switches will have to dill with so, in theory you will pay performance penalty.
However, today's network infrastructure can handle these kind of tasks with latency of a few nano-seconds.

As for the other option, it is recommanded under 2 conditions:
1. You don't own a 3rd layer switch (why buying expensive HW if you can provide solution without costs?)
2. Your other site has no direct connection to the first site (if it has, you'll have to change the other sit's IP subnet to say 192.168.100.0)

Author

Commented:
Hi All,

Thanks for comments.

Regarding the VLAN option, If i have to create a VLAN subinterface on the LAN interface of one of my routers to route between VLANs. Wont all the traffic from the Server VLAN to the Workstation VLAN have to cross this interface?

If this is a 100Mbit interface will the maximum bandwidth available for all workstations to reach servers be 100Mbit? This would be a significant drop compared to the 1Gbit uplinks i have joining switches currently
Commented:
Unlock this solution and get a sample of our free trial.
(No credit card required)
UNLOCK SOLUTION

Author

Commented:

I think the final solution will be to increase my subnet size, but this will not happen until i have a chance to reconfigure all infrastructure.

I might make a "printer" VLAN in the mean time to give me some breathing space..

Oriziv: I have a private network that uses the 10.0.0.0 range and i dont want to confuse internal LAN ranges with private network ranges..

Thanks for the good advice. Points split between Mikk and oriziv

Gain unlimited access to on-demand training courses with an Experts Exchange subscription.

Get Access
Why Experts Exchange?

Experts Exchange always has the answer, or at the least points me in the correct direction! It is like having another employee that is extremely experienced.

Jim Murphy
Programmer at Smart IT Solutions

When asked, what has been your best career decision?

Deciding to stick with EE.

Mohamed Asif
Technical Department Head

Being involved with EE helped me to grow personally and professionally.

Carl Webster
CTP, Sr Infrastructure Consultant
Empower Your Career
Did You Know?

We've partnered with two important charities to provide clean water and computer science education to those who need it most. READ MORE

Ask ANY Question

Connect with Certified Experts to gain insight and support on specific technology challenges including:

  • Troubleshooting
  • Research
  • Professional Opinions
Unlock the solution to this question.
Thanks for using Experts Exchange.

Please provide your email to receive a sample view!

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.