[CALUG] how to kill a process tree in PS

[Walt Smith]

hi,

I have a kppp kde dialer in CentOS6.8
( which generally works better than CentOS 7.x )
(I installed the x32 software hard disk into a x64 box ).

Its the gui dialer.
However, due to the way it's no longer integrated
nicely,  I need to keep a su terminal open to start or
stop  the kppp/pppd processes.

The question is this:
how can I kill a tree of processes?  I find the man page simply
comfusing.

example:

I'd like to kill all of the following in the tree, without listing
each process in the cli kill. 
IOW kill the "root" - 6484


[root at CentOS68 waltech]# ps axf | grep ppp
 6484 ?        Sl     0:00 kppp
 6486 ?        S      0:00  \_ /usr/sbin/userhelper -w kppp
 6494 ?        S      0:32      \_ kppp
 6495 ?        Ss     0:00          \_ kppp
 6510 ttyS0    Ss+    0:00              \_ pppd 115200 -detach defaultroute persist modem mtu 552 mru 552 holdoff 0 debug nolock chap-restart 3 noauth refuse-mschap refuse-mschap-v2 refuse-eap chap-interval 30 chap-max-challenge 1000 pap-max-authreq 1000 lcp-echo-interval 10 lcp-max-configure 100 lcp-echo-failure 10 nomagic pap-timeout 5 user waltech at tenex.org


thanks
Walt . . . 


----
 The government is lawless, not the press (people).
 ( [Supreme Court] Justice Douglas re: The Pentagon Papers )