http://www.ibm.com/developerworks/linux/library/l-linux-networking-stack/?ca=dgr-lnxw01lnxNetStack very basic description on linux kernel network stack, but contains a list of follow-up literature, so it’s a useful article, even if you are not a beginner
http://www.potaroo.net/tools/ipv4/index.html notes about IPv4 extinction and a move to IPv6
http://lists.us.dell.com/pipermail/linux-poweredge/2005-April/020095.html notes about dell switch hardware and linux ethernet bonding
http://enterprisenetworksandservers.com/monthly/art.php?2715 article explaning Cisco PIX packet flow. Pls read it if u are planning to touch pix config files