Calling 'ifup ppp0' twice without an intervening 'ifdown ppp0' causes the
interface to get stuck up. I am forced to switch to root and manually kill
pppd to bring the interface down.
This also happens when someone using usernet or rp3 logs out without closing the
connection, for default installation settings. To avoid this, it helps to set
PPPOPTIONS in /etc/sysconfig/network-scripts/ifcfg-ppp* to "idle 600" for
disconnection after 10 minutes of no traffic, and PERSIST to "no" to prevent it
trying to reconnect.
Please verify this with a newer version of Red Hat Enterprise Linux or Fedora
Core and reopen it against the new version if it still occurs.
Closing as "not a bug" for now.