topic How to Block MAC address in Operating System - Linux

How to Block MAC address

Mohammed Shahidul Islam — Fri, 14 Sep 2007 23:59:10 GMT

Dear

I am using RedHat 4 and squid for proxy. I need to block MAC address as we block IP address. Please inform me how to block mac in squid server.

Thanks with regards
shahid

Re: How to Block MAC address

Ivan Ferreira — Sat, 15 Sep 2007 13:53:48 GMT

Squid must be compiled with mac address support (--enable-arp-acl). Check with squid -v.

If it's enabled, then you need to configure an acl like this:

acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)

But I think that if you have dynamic IP configuration, then the preferred method is to use user based authentication.

Re: How to Block MAC address

Stuart Browne — Sat, 15 Sep 2007 17:07:56 GMT

Documentation is a wonderful thing..

This is from the 2.6 documentation:

acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)

( http://www.squid-cache.org/Versions/v2/2.6/cfgman/acl.html )

The 2.5 configuration file doesn't list it as a viable option (and 2.5.STABLE14 is what comes with RHEL4), so not sure if it will work. Give it a spin, see what happens.

If that doesn't work, fall back to using IPTables to filter based on MAC address:

iptables -A INPUT -j REJECT -m mac --mac-source -p tcp --dport 80

or some such..

Re: How to Block MAC address

Steven E. Protter — Mon, 17 Sep 2007 06:45:04 GMT

Shalom Mohammed,

Note that its easy to clone and forge mac addresses. Its very common and a feature in the setup of many internet sharing devices like wireless hubs.

If you are trying to block access to a particular site or system by mac address, they can stop the block merely by changing network configuration or actual NIC cards.

The situation is a little more simple if you are blocking an internal user.

SEP