Review your favorite Linux distribution.
Go Back > Forums > Linux Forums > Linux - Networking
User Name
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.


  Search this Thread
Old 01-07-2010, 11:46 AM   #1
LQ Newbie
Registered: Jan 2010
Posts: 7

Rep: Reputation: 0
Question DHCP:bad subnet/mask combination

Hi,I use following commands in dhcpd.conf and get the subnet number/mask combination err.please help me

subnet netmask {

what is my problem ?
Old 01-07-2010, 11:59 AM   #2
LQ Guru
Registered: May 2005
Location: Atlanta Georgia USA
Distribution: Redhat (RHEL), CentOS, Fedora, Debian, FreeBSD, HP-UX, Solaris, SCO
Posts: 6,274
Blog Entries: 10

Rep: Reputation: 847Reputation: 847Reputation: 847Reputation: 847Reputation: 847Reputation: 847Reputation: 847
To get the range you want you'd need to calculate the CIDR.

There are some good online tools for doing this.

If you go to:
Input as the IP address then select 14 as maximum address (lowest number that will accomodate the 10 you want) it will show you:

NETMASK should be
First IP is actually and last IP is This encompasses the range you specified ( - It also gives you the CIDR (/28).
1 members found this post helpful.
Old 01-07-2010, 12:02 PM   #3
LQ Newbie
Registered: Jan 2010
Posts: 7

Original Poster
Rep: Reputation: 0
thank you man useful,nice


dhcp, err

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
DHCP: Bad subnet number/mask combination OliXNet Linux - Networking 4 01-07-2010 11:17 AM
dhcp - bad subnet/mask combination ecunningham Linux - Server 2 03-19-2009 09:19 AM
ignoring dhcp requests on eth0 and wlan0 define subnet mask? Person_1873 Linux - Server 1 12-15-2007 06:58 AM
dhcpd server problem: bad subnet number/mask combination 144419855310001 Linux - Networking 2 09-13-2007 11:40 AM
Subnet Mask with 1 IP. Ionized Linux - Networking 25 06-10-2007 01:20 AM

All times are GMT -5. The time now is 09:57 AM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration