How to shut down an interface?

[otheos]

Sometimes due to the fact I connect to the internet using rp3 or wvdial from terminal, with the connection occasionally dropped or switching the modem off and on, I end up with the interface ppp0 still showing when I ifconfig.

If I try to reconnect (using either rp3 or wvdial) after pppd starts nothing comes in or out from the modem and ifconfig lists two ppp interfaces. If I disconnect the second goes away but the first one stays.

How can I shutdown the persistent interface so that I can reconnect?

I use RH6.2, thank you for you time.

[dvdnut]

hello fellow welshman

to drop the connection

ifdown ppp0

should work

also
ifup ppp0

gets it connected too!

[otheos]

Thank you,
however the problem is that even after the connection is dropped the interface is still up! so when I reconnect I get two ppp interfaces and nothing actually works.

I need to shutdown the left over ppp interface before I reconnect (and create a new one) for things to work. otherwise I connect, but no data passes through the new interface.