Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

Networking issue

Posted on 2015-01-20
10
Medium Priority
?
113 Views
Last Modified: 2015-01-21
We have a vlan 11 with a DHCP range of 10.11.20.1 - 10.11.254.254 default gateway of 10.11.0.1.

all clients that have an IP address of 10.11.0.x and work fine. All clients that get an IP of 10.11.1.x cannot ping anything (server, gateway, printers, not internet) or be pinged. All client on vlan11 have the same default gateway.

We have a Cisco firewall and cannot find any settings that could be causing this issue. Of course I could be overlooking something.

Not sure if the core switch would do anything. DHCP and DNS are controlled by a windows 2008 DC.

Any ideas?
0
Comment
Question by:bbayachek
[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
  • 5
  • 4
10 Comments
 
LVL 34

Expert Comment

by:Paul MacDonald
ID: 40559988
What subnet mask are you using?
0
 
LVL 1

Author Comment

by:bbayachek
ID: 40560000
255.255.248.0
0
 
LVL 1

Author Comment

by:bbayachek
ID: 40560009
I think you are on to something. Should we use 255.255.0.0? If so, it is greyed out in the DHCP settings on our windows dc
0
Prepare for your VMware VCP6-DCV exam.

Josh Coen and Jason Langer have prepared the latest edition of VCP study guide. Both authors have been working in the IT field for more than a decade, and both hold VMware certifications. This 163-page guide covers all 10 of the exam blueprint sections.

 
LVL 34

Expert Comment

by:Paul MacDonald
ID: 40560026
You can't change it, I believe, once you've established the DHCP Scope.  You have to re-create it.
0
 
LVL 1

Author Comment

by:bbayachek
ID: 40560063
that's not going to be fun. Would we use 255.255.0.0?
0
 
LVL 34

Expert Comment

by:Paul MacDonald
ID: 40560082
"Would we use 255.255.0.0?"
I can't answer that question for you.  It seems like it would be valid for you, but whether or not it's the best choice...

If creating a new scope is too much trouble, you can create a superscope instead and proceed that way.
0
 
LVL 1

Author Comment

by:bbayachek
ID: 40560142
i just looked at the settings we are using on a IP address calc.

The subnet mask that we are using should be fine. It has a range of 10.11.0.1 - 10.11.7.254
0
 
LVL 1

Author Comment

by:bbayachek
ID: 40560458
ok I found the issue. It was our settings in our core switch. VLAN11 is using subnet mask 255.255.255.0. My new question is if I change the vlan 11 subnet mask to 255.255.248.0 on the core switch would it cause any issues with the devices that are already connected? Will it change the settings in all my other switches?
0
 

Accepted Solution

by:
Jagrenet earned 1000 total points
ID: 40560499
If you change the subnet mask to 255.255.248.0 it should not affect any of the devices that are already connected. When the DHCP lease expires, the devices will get a new IP address with the new subnet mask and connectivity should remain seamless to the end user. Obviously, this means changing the subnet mask in the DHCP scope as well.

Your next question, "Will it change the settings in all my other switches? ". This depends .... are you using VTP (VLAN trunking protocol) in your environment? If so, how is it configured? - (i.e Server, Client or Transparent mode)

How many IP Addresses do you have configured for VLAN11 (on separate SVI's)?
We need a little more info.
0
 
LVL 34

Assisted Solution

by:Paul MacDonald
Paul MacDonald earned 1000 total points
ID: 40561905
"ok I found the issue."
Great!  And as noted, there shouldn't be any consequences to changing the mask.
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

Originally, this post was published on Monitis Blog, you can check it here . It goes without saying that technology has transformed society and the very nature of how we live, work, and communicate in ways that would’ve been incomprehensible 5 ye…
On Feb. 28, Amazon’s Simple Storage Service (S3) went down after an employee issued the wrong command during a debugging exercise. Among those affected were big names like Netflix, Spotify and Expedia.
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…
In this tutorial you'll learn about bandwidth monitoring with flows and packet sniffing with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're interested in additional methods for monitoring bandwidt…

610 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