Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
?
Solved

Range of ip's with ipchains?

Posted on 2000-02-17
2
Medium Priority
?
247 Views
Last Modified: 2010-04-20
I'm trying to set up a firewall with ipchains on a dialin server which would allow internet access but limit access to the LAN. The dialup server is a different machine than the gateway so I need some way of denying packets that are going to the local network.I tried to use the
ipchains -A output -i eth0 -d ! x.x.x.x
-j ACCEPT

directive, where x.x.x.x is the base address of the LAN as in 192.168.8.0 but this does not work. I have a statement with Masquerading as well, but that doesn't work either(this statement may be wrong though...) I've also tried restricting access to only the gateway machine, which worked, but then I was restricted from internet access as well.
The only way I can see that it would work would be to put in individual DENY statements for each of the machines on the LAN. I really don't want to have to do this, so I was wondering if there's a way to specify a range of addresses in a DENY statement? I thought by using the base address(192.168.8.0) it would deny to all machines(192.168.8.*) but that's not the case.
Please help,

Thanks
0
Comment
Question by:tibori
2 Comments
 
LVL 3

Accepted Solution

by:
RobWMartin earned 0 total points
ID: 2532997
Out of context, I don't understand what the ipchains command you supplied is doing.  However, to get a range of addresses you can use the netmask.  Short form looks like this:

X.X.X.X/24

where the 24 is the number of bits on the left to match; in this case 24 bits means the first 3 numbers.  16 would be the first 2 numbers. etc.

Rob
0
 
LVL 3

Author Comment

by:tibori
ID: 2533049
Thanks, that's what I needed, and it worked.
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Question has a verified solution.

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

I. Introduction There's an interesting discussion going on now in an Experts Exchange Group — Attachments with no extension . This reminded me of questions that come up here at EE along the lines of, "How can I tell the type of file from its cont…
Often times it's very very easy to extend a volume on a Linux instance in AWS, but impossible to shrink it. I wanted to contribute to the experts-exchange community a way of providing a procedure that works on an AWS instance. It can also be used on…
Learn several ways to interact with files and get file information from the bash shell. ls lists the contents of a directory: Using the -a flag displays hidden files: Using the -l flag formats the output in a long list: The file command gives us mor…
Learn how to get help with Linux/Unix bash shell commands. Use help to read help documents for built in bash shell commands.: Use man to interface with the online reference manuals for shell commands.: Use man to search man pages for unknown command…
Suggested Courses
Course of the Month15 days, 4 hours left to enroll

578 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