My NIC configuration is not stable. Any time I reboot, I have to swap eth0 and eth1. Any Help!!

give us your scenario what is your route table look like etc in know in my case i had to specify the external gateway for both cards etc... another work around could be to place a script using ifconfig in your rc.local folder so its last to be run and fixes the issue etc.. but need more info..

My route table is not the problem. As at now I can communicate with my LAN and WAN, but when I reboot I will not be able to communicate with either my LAN or my WAN. Then, I would have to swap eth0 and eth1, and also effect some changes in my route table before I can communicate. If I reboot again, I am back to square one (I can't communicate).

fixed ip or dhcp what are you using try setting both gateways as your external gateway and set a static route for the internal thats how i resolved my same issue for security at work i also wrote scripts for the .profile so that after a person was done it shut down the external card and when needed reinitiallized them you could simply wtite a shell script and place it on the desktop that resets ifconfig and the route example example (im assuming your not logged in as root even though everyone does it including my self sometimes but here goes) i will signify line end by (e) #!/bin/sh sudo ifconfig etho 1.1.1.1 netmask 255.255.255.0 broadcast 1.1.1.255(e) sudo route add default gw 1.1.1.2 dev eth0(e) sudo ifconfig eth0 up(e) exit(e) exit(e) simply do an ifconfig down first then add lines for eth1 as well this way when your desktop comes up you just double click the file or place it in your rc.local folder or .profile file to automatically do this at boot time but if you repost include the messed up route table and any logs or dead.letter info you can thanks