Comprehensive System Administration
Lecture 1 notes:
2001-10-26 (Fri)NFS
To export to other machines, use: /etc/exports However, on Solaris, use: /etc/dfs/dfstab File usage: directory machine1 (options) machine2 (options) Example: /mp3 192.168.0.5(ro) 192.221.58.0/255.255.255.0(ro,rw) where ro = Read Only rw = Read/Write - Can be used as comma seperated values to select more that one option. - Machine2's usage allows access to any machine that begins with 192.221.58.x How to mount a shared directory: mount -t nfs server:/mp3 /server/mp3 filesystem | mountpoint | ftype | options | dump | pass server:/mp3 /server/mp3 nfs ro, defaults 0 0 On Solaris: share -Fnfs /mp3 // to share unshare /mp3 // to unshareNetworking
- Check out CS61c's calendar page for info about networking.IP Addresses
24.20.160.210 // Calman's IP address, good place for a DoS attack... IP Addresses are written at four numbers that range from 0 to 255 and are broken up into 5 classes: First Field Class 8-bit 8-bit 8-bit 8-bit 0-127 A Net Host Host Host 128-191 B Net Net Host Host 192-223 C Net Net Net Host Special Reserved IP's: 10.0.0.0 / 255.0.0.0 // For class A 127.0.0.1 // Loopback - always points to your machine 198.168.0.0 / 255.255.255.0 // For class CSubnets
A subnet is a group of machines that have a direct connection to each other, i.e., they are all on the same switch or router. In order to talk to a computer outside of your subnet, you have to go through a gateway. Suppose you have a class C IP: 128.32.42.x 128.32.42.0 and 128.32.42.255 are reserved So you have 256 - 2 or 254 free IPs on your subnet. How do you tell who is on your subnet? Use a subnet mask. For our example, the subnet mask 255.255.255.0 will allow us to access all machines in our subnet. The 255.255.255's only alows one value each, or 128.32.42 and the O allows any value between 0 and 255 to pass through.