Increase DHCP scope/subnet mask

Hi,
Windows Server 2003, IP Range 192.168.0.1 - 192.168.0.254, Subnet 255.255.255.0.
Now I'm facing shortage of IP.
Planing to increase the IP range. Which one is preferable -
Scope Extension
Resubnetting
Superscoping
Which one would not affect or less affect my current settings.
Thanks,
Sathish

Hi,
I've Configured Superscope as suggested.
First IP range - 192.168.0.1
Superscope IP I've added is - 192.168.3.1
Both the IP's are communication each other. I'm in a critical situation now.
None of the above IP's are communicating with the Internet. When I ping to the google dns 8.8.8.8 it's replying, but when I ping or browse google or any other the page is not loading.
I'm using a Wingate Proxy, given Wingate Proxy server IP (192.168.0.140) as gateway IP while configuring superscope.
When I tracert 8.8.8.8
* * * * request timedout
ping to 192.168.1.1
ping to public IP
Here 192.168.1.1 is the router IP.
Could any one Suggest me the solution, what is to be done to resolve this issue.
Sathish

Similar Messages

DHCP scope increase and changes in wlc

hi,
i am using wlc 4402 with a mgt ip 172.26.150.x/24 and ap manager ip 172.26.150.x/24, my all ap get the ip address from dhcp . currently in dhcp server 172.26.150.3 to 254 dhcp scope is configured. at mysite some devices are configured like ipad,iphone or galaxy tab with mac binding in dhcp server. now this pool is almost full. i have a policy configured for these devices for mac binding is done in DHCP. to increase pool what are the changes i need to do in wlc. what are the changes i need to do in dhcp server . is policy made for mac binding in dhcp server will get affected by this ?
regards
rajat

Hi Rajat,
Use a /23 range ip address rather than using 172.26.150.x/24. So at first this change need to be carried out on the L3 device (which will the default gateway of the WLC managment interface). Accordingly the AP managment ip and ap manager ip's subnet mask is going to change from /24 to /23.
Then ensure that on the dhcp server you expand the scope from /24 to /23. This is will not affect the MAC bindings as long as you are using the same ip range with a different subnet mask.
Hope that helps
Regards
Najaf
Please rate when applicable or helpful !!!

HT1218 I'm trying to set up a new iPad..it asks for my WiFi network.. I find the network..then it asks for information that I have no idea about: IP address, Subnet Mask, Routet, DNS, Search Domains, Client ID..also the headings are: DHCP,BootP, Static..c

I am trying to set up my new iPad. it asks for a WiFi connection.. I have one..then the next page asks for these things:DHCP,BootP,Ststic then IP address, Subnet Mask, Router, DNS, Search Domain, Client ID then HTTP Proxy I have no idea what any of this means...can someone please help me???

Thank you sooo much. I was so disappointed...I couldn't wait to get started with the new iPad..then ran into the problem. So simple. You made my day. Thank you for your expertise!!

Internal DHCP scope for AP on WLC 7.0 (on diff subnet)

hi All,
I would like to know if it is possible to assign dhcp pool on a different subnet to the WLC management interface?
Eg: Management Interface is on 172.16.4.100 /24
I would like to use the WLC Internal DHCP to assign IP to my APs on the a different range 172.16.2.x /24
Is that possible?
I have tried assigning dhcp scope for the AP within the same subnet as the management interface and it works. But that is not my requirement
Apparently i need my AP to be sitting on a different vlan
please advise

No its not possible.. this works only if the AP and the WLC management interface is in the same subnet!! to ur issue we use something called as DHCP OPTION 43, google search DHCP OPTION 43 + cisco, the first link that u get wil help you!!
Please dont forget to rate the usefull posts!!
Regards
Surendra

DHCP scope full, event ID 1020

Hi, one of our Windows 2008 R2 Domain controllers is returning the following warning message on almost a daily basis:
Log Name:      System
Source:        Microsoft-Windows-DHCP-Server
Date:          19/11/2014 11:32:41 AM
Event ID:      1020
Task Category: None
Level:         Warning
Keywords:      Classic
User:          N/A
Computer:      computername.domain.x.x
Description:
Scope, 10.x.x.0, is 83 percent full with only 39 IP addresses remaining.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
    <Provider Name="Microsoft-Windows-DHCP-Server" Guid="{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" EventSourceName="DhcpServer" />
    <EventID Qualifiers="0">1020</EventID>
    <Version>0</Version>
    <Level>3</Level>
    <Task>0</Task>
    <Opcode>0</Opcode>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2014-11-19T00:32:41.000000000Z" />
    <EventRecordID>12980</EventRecordID>
    <Correlation />
    <Execution ProcessID="0" ThreadID="0" />
    <Channel>System</Channel>
    <Computer>computer.domain.x.x</Computer>
    <Security />
</System>
<EventData>
    <Data>10.x.x.x</Data>
    <Data>83</Data>
    <Data>39</Data>
</EventData>
</Event>
Upon review of Microsoft Support online, I found the following article which illustrates a few options:
http://support.microsoft.com/kb/255999/en-au
What would be the logical choice for us, having the 10.x.x network?
Ideally, it would be good not having to re-subnet anything if possible, or re-create the scope.
Would a scope extension require a reboot of the server? Never done this before, so thought I should ask.

Hi,
According to your description, my understanding is that DC prompts an warning event ID 1020, indicate 83% full with DHCP scope.
By default, the threshold value for firing of event 1020 is 80%. Estimate devices number, contrast with the number of IP address in this scope, if the percentage is less than 80%, you may try to reduce the lease duration and decrease the cleanup interval.
This can help to speed the reclaiming of expired scope IP addresses.
To reduce the lease duration:
1.At the DHCP server, click Start, point to Administrative Tools, and then click
DHCP.
2.In the DCHP console tree, right-click the scope you want to configure, and then click
Properties.
3.On the General tab, under Lease duration for DHCP clients, type the new lease duration.
To use a Netsh command to set the cleanup interval time:
1.At the DHCP server, click Start, click Run, type
cmd, and then press ENTER.
2.Type netsh dhcp set databasecleanupinterval <NewInterval> (where "NewInterval" is the amount of time in minutes between DHCP database cleanups).
As an existing DHCP scope, its subnet mask can’t be changed. If the Start Address and
End Address do not currently include all addresses for your specific subnet, you can increase the number of addresses in the scope by extending the
Start Address or End Address in the scope properties. This operation needn’t reboot.
If neither of above 2 suggestions is applicable, new a DHCP scope or reference
KB255999 (resubnetting and superscoping). At the same time, you need to change your network topology.
Best Regards,
Eve Wang

Wlc 5508 webauth subnet mask change issue

Recenly l changed the network subnet for a particular wlc interface and scope and also an upstream router and for some reason it would only allow me to use a /24 Host mask as my plan was to go to a /22 mask to allow for over 1000 hosts within this scope.
The Upstream Router which is a ( RV042 ) had the following original config :
     192.168.1.1
     255.255.255.0
I have noticed this device will not let me change the mask from a /24 to a /22 as you can only change from a pre-defined list of masks and you cannot manually add any either..
New Config
     10.10.0.10
     255.255.255.0
WLC 5508 Controller Interface
     Original Config
      192.168.1.25
     255.255.255.0
     192.168.1.1
     New Config
     10.10.0.25
     255.255.252.0
     Scope
     Range : 10.10.1.10 - 10.10.3.254
     Mask : 255.255.252.0
     Network : 10.0.0.0
     Router : 10.10.0.10
When l reconfigure to this addressing the wireless clients connect and get the new dhcp scope details but following this the webauth screen doesn't appear not allowing them to connect meaning there is no routing of traffic / internet access.
If l modify the above interface and scope masks back to a /24 - 255.255.255.0 the the wireless clients connect and webauth appears to prompt them to accept the terms and conditions and connect thus giving them internet access.
It looks like an issue with the mask ? The main reason l am trying to change the subnet addressing is because the standard /24 mask is not providing enough dhcp addresses and we have had times were the scope has been exhausted due to the public connecting and disconnecting as the lease perod of 2 hours holds onto the address before expiring meaning there is not enough available addresses for people to connect.
I would of thought that the upstream router ( RV042 ) even though it is only a /24 mask would still route the traffic coming from a WLC Controller interface with a /22 mask ?
Hopefully someone can suggest a solution ?
Thanks Simon

Hey Scott just getting back to this issue..   If for instance l can modify the wlc interface and Scope to have a /22 mask ( 1022 Hosts ) and my upstream Router ( Cisco RV042 ) can only provide a /24 or higher mask then does that mean l am still limited to a range of 254 hosts ( /24 Mask ) ? Would this mean l need to look into replacing my upstream Cisco RV042 VPN Router ?

DHCP scope

Hi all i am facing issue with creating new scope in windows server 2012
i have created a dhcp server on windows server with the details
below.
ip address 192.168.137.1
subnet mask : 255.255.255.0
now i am creating a new scope its not letting me do
i am creating a new scope with 192.168.137.211
or any its not let me create
but if am selecting
10.1.10.100
to
10.1.10.200
with subnet 255.0.0.0
its created but when i am using the same on my added client windows 7 enterprise it is not able to ping to primary machine
plz suggest me ..
help me

Hi,
If you create the scope with the subnet mask 255.0.0.0, the scope would be 10.0.0.0/8. Since the 10.0.0.0/8 and the 192.168.127.0/24 are not in the same subnet, if you have
no router between them, it would be impossible for them to connection.
A DHCP server can only service requests for a scope whose network ID is the same as the network ID of its IP address without superscope or router. Since you DHCP server is
in 192.168.127.0/24, you can add a scope with IP range from 192.168.137.2 to 192.168.137.254 with subnet mask 255.255.255.0.
In addition, the links below would be helpful for you to better understand:
Subnetting
Configuring a DHCP Superscope
DHCP Clients Are Unable to Get IP Addresses from a DHCP Server
Best regards,
Susie

New DHCP scope

Hi spice family..We have a 2008 domain environment and just added a new 2008 DC toone of ourbuildings (bld3). All the pcs and printers are currently assigned IPs from a DHCP server from another building (bld2). DHCP server at bld2 is serving out IPs to bld2 and bld3. I want to set up the new DC as a DHCP server for bld3 only with a new scope. currently: Bld2 DHCP scope - 192.169.70.100 - 192.168.70.230Goal: Bld3 DHCP scope - 192.168.72.50 - 192.168.72.200Oh, I forgot to mention that there is also a file server at bld3 that the users access there. So, all devices are currently on the 70 subnet there and I want to migrate everything to the 72 except for the statically assigned printers. We will leave half of the ports on the switch on the 70 subnet for the printers. What would be the best solution for this? and will it break the shares...
This topic first appeared in the Spiceworks Community

Lieberman Software released a study today that finds 87% of IT pros believe the reports of security breaches among financial institutions belie the true number of hacks occurring within the industry.According to eWeek, the report, which surveyed nearly 150 IT pros, concludes that IT faces a lack of confidence concerning of advanced persistent threat (APT) attacks and how organizations are able to deal with them.Speaking with eWeek, the current President of Lieberman Software, Philip Lieberman, explained that the rising use of "automation among attackers and the increased use of zero days and unpatched vulnerabilities are adding to [the security risks that organizations face]." While IT is partof the problem, Lieberman places a larger portion of blame with senior leadership, which doesn't build "resiliency into their business operations...

The subnet mask on the Extreme isn't the same as on the Express.

Dear Group,
I have my Extreme configured to do PPPoE and DHCP and my DSL modem is setup as bridged. Everything is finally working well. I have an Express extending the Extreme in a WDS.
When I look at the PPPoE tab in the Internet tab of the Extreme in AirPort Utility it shows a subnet mask of 255.255.255.255, but the Internet tab of the Express shows 255.255.255.0.
I don't have any problems at all and wireless clients are connected to the Extreme and the Express.
Is the Extreme's subnet mask part of my DSL connection and therefore a different subnet mask?
Not sure, but I'd like to make sure that I don't have something setup incorrectly.
Thanks,
Frank

This really isn't an issue as long as the AirPort Extreme base station (AEBS) is providing a working Internet connection. Since the AEBS is using PPPoE to connect to your ISP I'm not sure that the subnet mask is even used.
The subnet value of 255.255.255.0 used by the AirPort Express (AX) is typical.

Assigning non-standard subnet mask to local IP address on WRT54GX

I need to configure my WRT54GX V1 as an access point. I know how to accomplish this, but our corporate network uses a subnet mask of 255.255.252.0 How can I assign this net mask? The only options are contained in a drop-down menu and what I need is not there. Is there a different way to assign the subnet mask rather than using the menues?

It is a known limitation of Linksys wireless routers that they only support LAN subnets up to 255.255.255.0. I guess the assumption was that the router only runs LANs for up to 253 LAN devices. The plain access point setup (i.e. uplink through LAN-LAN connection) was never properly considered an option although it is documented in the Linksys easy answers.
Anyway, to set up the WRT as access point the LAN IP address of the WRT and the subnet mask is not important for the wireless connectivity into the LAN. The LAN IP address and subnet mask is only relevant to access the web interface of the WRT to make configuration changes. You have to make sure that the DHCP server on the WRT is turned off and that a LAN port of the WRT is wired to your existing LAN.
For the LAN IP address setup you have three options:
1. Use an available IP address inside your LAN and use subnet mask 255.255.255.0, e.g. if your LAN uses 10.0.0.0/255.255.252.0, assign the WRT an IP address of 10.0.3.200 with subnet mask 255.255.255.0. Of course, in that case you are only able to access the web interface of the WRT http://10.0.3.200/ from a computer in 10.0.3.* because that's the IP subnet which the WRT thinks is connected to its LAN ports. You cannot use a computer with IP address 10.0.{0,1,2}.* because the WRT does not know how to route these IP addresses. If your computer has an IP address outside the configured WRT LAN subnet you must temporarily change the IP address of the computer.
2. If you assign a LAN IP address and subnet mask to your WRT which includes a network router you may be able to get full connectivity by setting up static routes in the WRT. For instance, if you assign 10.0.3.200/255.255.255.0 to your WRT and your main LAN router sits at 10.0.3.254/255.255.252.0 you may be able to set up static routes for destinations 10.0.0.0/255.255.254.0 and 10.0.2.0/255.255.255.0 (or if it works even simply destination 10.0.0.0/255.255.252.0) to gateway IP address 10.0.3.254 on the LAN interface. Traffic from the computer to the router should go directly while the responses from the router to the computer go through the main router. I think this should work although I am not 100% sure.
3. Use any IP address outside your LAN, e.g. the default 192.168.1.1/255.255.255.0. Again, you must temporarily set up a static IP address on your computer to gain access to the web interface. But even with a LAN IP address outside your LAN the WRT will still bridge wireless clients into the LAN as it is supposed to do.

Client Authentication/Authorization via ISE & AD, Posture Registry Key, and mapped to specific DHCP scope by AD membership

Hi Team,
I'm currently working on a configuration entailing WLC and ISE where the customer wants a single SSID,and wants his wireless clients to authenticate successfully if they pass a registry key compliance. Additionally, they want clients to received a different IP address or get mapped to a different DHCP scope based on the Microsoft AD group they belong too. for example:
Client authenticating with registry key and in AD group ABC that passes authentication gets IP address or subnet for AD group ABC.
Client authenticating with registry key and in AD group XXX that passes authentication gets IP address or subnet for AD group XXX.
Clients---->WLC------>ISE-----> MS AD ( groups ABC, XXXX, YYY )
currently using EAP-PEAP/MSCHAPv2
Does anyone have any idea or pointers or can refer me somewhere that I can read on how to accomplish this? Not sure on how to do the registry compliance check nor what attributes will allow me to map the client to a DHCP Scope based on this AD group membership?
Thanks...

Do check cisco how to guides you will get step by step configuration of the current requirement

Ip address & subnet mask !

I have recently encountered a problem with my system and the assigned IP Address and was not sure why. I have a wireless connection on the iMac with it setup to get the IP address automatically but the system gets the wrong subnet mask every time. It gets (255.255.0.0) the correct subnext mask in the other mac's is (255.255.255.0). Where is it getting the inappropriate address and why does it didn't assign the correct one!!

Are you sure that both these macs are getting IP addresses from the same place? (1 wired, 1 wireless...might mean that mac2 is getting neighbor's wifi)
Are you certain that this trouble mac is configured to be fully Automatic in the NetworkSystemPreferences?
"Conigure IPv4...Using DHCP" ( not manually, not dhcp with manual address, not bootP...)
Have you done a cold start to all your network devices (macs, router, modem, network printers?)
Power-cycle them off. Count 2 minutes. Start up modem, pause. Start up router/BaseStation, pause. Start up mac(s).
You haven't said what kind of router/baseStation you've got. 'Twould help, maybe.
added: Do you have a wireless modem/router AND a wireless airportBS/router/something)?
Message was edited by: Rick Van Vliet
Message was edited by: Rick Van Vliet

Why would Airport change subnet mask?

Hello all.. kinda new to this stuff and was looking around for an answer, but couldn't find my exact situation. So, forgive me if I ask some stupid questions... Ok, I have MacBook Pro, and recently had to do a reset on my modem/router, and now this particular computer won't connect wirelessly. I also have a macbook air, and connects fine wirelessly. It seems I have narrowed it down to the subnet mask... maybe, but not completely sure. Just to be clear, I don't have the Airport express, I am just simply talking about the airport function built in to connect to a wireless network (not sure if it's called something different, or is the one on the actual computer just called airport?). So, going into the airport utility does nothing for me. It can't find any wireless devices. And everything I have read has been talking about going into that program and changing things. Anyways, I tried connecting automatically (using DHCP) and manually, but nothing helps. My macbook air gets a subnet mask of 255.255.255.0, while it has now started giving my macbook pro a 255.255.0.0. And I'm assuming my router is still configured for 255.255.255.0, but now my computer isn't.. How is that possible? Just wondering if anyone knew why this was happening and/or how I can fix it. Like I said, I'm not a genius with this stuff, but any help would be appreciated. Thanks for your help! And if I have missed any important information, let me know..

Unless you have an Apple-brand Wi-Fi base station, AirPort Utility is of no use to you.
It might help to reset the connection settings on your MacBook Pro using these steps one at a time until the problem is resolved, recognizing that, depending on your problem, not all of these steps will make sense:
1) Use the AirPort menu bar item to turn AirPort off, then on again.
2) Try to select your Wi-Fi network from the AirPort menu.
3) In the Network panel of System Preferences delete the AirPort item from the left column, then add it back.
4) In the same panel as (3), define a new location and see if you can make that work.
5) In the same panel, select the AirPort connection item, click the "Advanced" button, select the "TCP/IP" tab, then click "Renew DHCP Lease". Note that the fix this step implements may be temporary.
6) In the folder /Library/Preferences ( _not_ <yourhomefolder>/Library/Preferences), move the folder SystemConfiguration onto the Desktop, then restart your computer. See if you can now make your AirPort connection work.
These steps may not help, but they'll only take a couple of minutes to try. Before you try these, if you have any special network settings on your Mac for things like DSL credentials, note all your network settings, because the latter steps will destroy them. If you got all the way to the last step, if things don't work any worse than before, you can trash the saved SystemConfiguration folder.

Is there a way for internal DHCP Scope to release scope addresses when the wifi client has disconnected?

DHCP scope is configured on a WLC 5508.
I'm checking if there' a way for WLC to clear the dhcp leasing when a user is diconnected from wireless?

Unless the client sends a DHCP Release upon disconnect, which is not mandaded in the protocol, the lease will simply remain until it has expired. If you're concerned with running out of leases, you only have 2 options.
1. reduce the lease time of your dhcp scope
2. increase the network size to accomodate more usable addresses.
There isn't a way to force a DHCP address lease to be "cleared" from the WLC simply because the client was disconnected.

"IP and router address not consistent with subnet mask"

Hi all,
i have one of the old Powermac G5's running os x 10.3.5 "Panther" with a dual 2.5ghz processor, 512mb or ram, 160 gig hd, and no wireless card. I've been trying to hook the computer up to my network via an Ethernet cable (I have a Linksys WRT54G series router).
the problem is this: When I go through the Network utilities using the "assist me" option, select the LAN option, put in the necessary information (IP address, subnet mask, router address, and the dns host), and select continue, this message pops up:"IP and router address not consistent with subnet mask".
What I've found is that no matter if the computer is plugged in with a cable to the Ethernet port the message comes up which is very unusual.
Thanks in advance.

Have you verified that you indeed have the proper subnet entered?
Why don't you just let the Mac obtain its ip address from the router via DHCP?

Increase DHCP scope/subnet mask

Similar Messages

Maybe you are looking for