Вывод route до и после подключения покажи
linux:~ # route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 * 255.255.255.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 0 0 0 eth0
loopback * 255.0.0.0 U 0 0 0 lo
default 192.168.0.1 0.0.0.0 UG 0 0 0 eth0
linux:~ # cable-start
Using interface ppp0
Connect: ppp0 <--> /dev/pts/2
CHAP authentication succeeded: Welcome^M^J
CHAP authentication succeeded
not replacing default route to eth0 [192.168.0.1]local IP address 81.30.176.250
remote IP address 10.8.0.8
Script /etc/ppp/ip-up finished (pid 4592), status = 0x0
linux:~ # route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.8.0.8 * 255.255.255.255 UH 0 0 0 ppp0
192.168.0.0 * 255.255.255.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 0 0 0 eth0
loopback * 255.0.0.0 U 0 0 0 lo
default 192.168.0.1 0.0.0.0 UG 0 0 0 eth0