Linux - NetworkingThis forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Introduction to Linux - A Hands on Guide
This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter.
For more advanced trainees it can be a desktop reference, and a collection of the base knowledge needed to proceed with system and network administration. This book contains many real life examples derived from the author's experience as a Linux system and network administrator, trainer and consultant. They hope these examples will help you to get a better understanding of the Linux system and that you feel encouraged to try out things on your own.
Click Here to receive this Complete Guide absolutely free.
Im looking for an IPTables aficionado who can help me here.
Here is the situation. I have a host with two IP addresses. One is management, the other is the blackhole.
When we have a know-bad destination address (botnet, callout, etc) and we want to know all the sources attempting to use it, we set a company wide route to force traffic to be "next hop" to be the balckhole IP. I have snort sitting on that interface and snort tells me who the sources are that try to callout. So the source tries to go to 22.214.171.124 (bad) but instead gets routed to 10.10.10.5 (blackhole with snort). No biggie.
If you are tempted to say "Why not monitor your egress, FW, etc - that seems like overkill!?" Just trust me, this is the only way to capture all the sources given the very disparate network that we have. Lots of egress. The blackhole route eliminates multiple local egresses and forces everyone to my central IP.
So here is my request. Because the traffic destined towards the balckhole is likely malicious - I am paranoid. I want to put in an IPtables rule to ensure that my blackhole IP is fully passive - it does not respond. But I DO need it to reply to ARPs so that the switch sees the blackhole IP as alive and continues make it routable (and possibly ICMP for convenience/heath checks)
So Can I put in a rule that basically allows everything IN to the interface, but only allows ARPs (or maybe just all layer two stuff?) out? If possible Arps and ICMP to specific set of destinations?