Linux - NewbieThis Linux forum is for members that are new to Linux.
Just starting out and have a question?
If it is not in the man pages or the how-to's this is the place!
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.
I have a server with 2+ network interfaces (pick a number). Each of the interfaces is defined as such:
iface ethx inet dhcp
Each of the interfaces has been assigned an IP address based on its MAC address; that is, the network admin has created a manual DHCP lease for that MAC address and only that MAC address. We are also using sticky-ARPs, meaning that no other MAC address can obtain the IP of another without have the ARP entry cleared.
The problem begins occuring 5 minutes after each NIC obtains its IP address, and continues to appear in the logs in five minute increments. Errors begin showing up in the DHCP server logs indicating that the NICs are attempting to use the IP addresses of other interfaces.
For example, eth0 obtains ip address 184.108.40.206, eth1 obtains address 220.127.116.11, and eth2 obtains 18.104.22.168. The DHCP server soon begins reporting that the MAC address of eth2 is attempting to send traffic through the address of eth0, eth1 is attempting to send traffic through the address of eth2, and so on. Ifconfig shows that the ip and MAC addresses match up properly, as does to the leases in the DHCP server.
If we use only two network interfaces, this problem does not manifest. It only shows up when using more than two interfaces.
Is this a problem with multiple adapters? Can this problem be fixed by using static addresses? Is this problem only evident in Debian Linux?
Enterprise Systems Administrator
Missouri State University
You cannot have network cards in the same box on the the same subnet and achieve any form of routing because the network gets confused as you have found out. They must be on different subnets as described above in order to achieve routing. The boxes attached to each card however, must be on the same subnet as the card they are attached to.