I have the same problem.
I tried to check ifcfg and found the error message below:
line 25:[:too many arguments
line 26:[:-ge: unary operator expected
line 27:[:-ge: unary operator expected
line 28:[:-ge: unary operator expected
SIOCGIFFLAGS : No such device
./ifup:configuration for ppp0 not found
still trying to figure out what happened.
any help is appreciated.
Thanks.