25.3. 一个示例/etc/ppp/ip-up脚本

下面的示例提供了各种用例。

#!/bin/bash # # Script which handles the routing issues as necessary for pppd # Only the link to Newman requires this handling. # # When the ppp link comes up, this script is called with the following # parameters # $1 the interface name used by pppd (e.g. ppp3) # $2 the tty device name # $3 the tty device speed # $4 the local IP address for the interface # $5 the remote IP address # $6 the parameter specified by the 'ipparam' option to pppd # case "$5" in # Handle the routing to the Newman Campus server 202.12.126.1) /sbin/route add -net 202.12.126.0 gw 202.12.126.1 # and flush the mail queue to get their email there asap! /usr/sbin/sendmail -q & ;; 139.130.177.2) # Our Internet link # When the link comes up, start the time server and synchronise to the world # provided it is not already running if [ ! -f /var/lock/subsys/xntpd ]; then /etc/rc.d/init.d/xntpd.init start & fi # Start the news server (if not already running) if [ ! -f /var/lock/subsys/news ]; then /etc/rc.d/init.d/news start & fi ;; 203.18.8.104) # Get the email down to my home machine as soon as the link comes up # No routing is required as my home Ethernet is handled by IP # masquerade and proxyarp routing. /usr/sbin/sendmail -q & ;; *) esac exit 0

由于建立了到我们 Newman 校区的 ppp 链路以及使用了这个脚本，我们最终得到了以下路由表条目（这台机器也是我们通用的拨号 PPP 服务器，并且处理我们的 Internet 链路）。我已经在输出中穿插了注释，以帮助解释每个条目的含义）:-

[root@kepler /root]# route -n Kernel routing table Destination Gateway Genmask Flags MSS Window Use Iface # the HOST route to our remote internet gateway 139.130.177.2 * 255.255.255.255 UH 1500 0 134 ppp4 # the HOST route to our Newman campus server 202.12.126.1 * 255.255.255.255 UH 1500 0 82 ppp5 # the HOST route to my home ethernet 203.18.8.104 * 255.255.255.255 UH 1500 0 74 ppp3 # two of our general dial up PPP lines 203.18.8.64 * 255.255.255.255 UH 552 0 0 ppp2 203.18.8.62 * 255.255.255.255 UH 552 0 1 ppp1 # the specific network route to the Newman campus LAN 202.12.126.0 202.12.126.1 255.255.255.0 UG 1500 0 0 ppp5 # the route to our local Ethernet (super-netting two adjacent C classes) 203.18.8.0 * 255.255.254.0 U 1500 0 1683 eth0 # the route to the loop back device 127.0.0.0 * 255.0.0.0 U 3584 0 483 lo # the default route to the Internet default 139.130.177.2 * UG 1500 0 3633 ppp4