Ren> [deleted /etc/init.d/networkings with office/home query] Ren> and it works good. my question here is: 1) is ifup/ifdown Ren> written in c and realized a set function of ifconfig and add Ren> route table? 2) how can i use ifconfig to bring up eth0 with Ren> dhcp?
Ren, I suggest you 'man interfaces'. The man page has an example of how to use the 'mapping' keyword to do exactly what you want, choose a home/office setting to decide how to bring up the interface. I wish I could help you more, but I don't currently use the mapping method. You don't use ifconfig to bring up eth0 with dhcp. You use a dhcp client which (most likely) uses ifconfig to bring up eth0. For example, if you really want to do this by hand, your networking script needs to run something like 'pump -i eth0' when you decide you do want to do dhcp. Cheers! Shyamal