Suggest you check out the following link for supported kernels and pptp.
http://pptpclient.sourceforge.net/howto-redhat-73.phtml
hope above is useful
It looks useful, I see that the latest Fedora Legacy kernel is listed: 2.4.20-30.7.legacy
[root@test]# rpm -ql -p kernel-mppe-2.4.20-30.7.legacy.i686.rpm
/lib/modules/2.4.20-30.7.legacy/kernel/drivers/net/ppp_generic_mppe.o
/lib/modules/2.4.20-30.7.legacy/kernel/drivers/net/ppp_mppe.o
[root@test]# rpm -ql ppp-modules
/lib/modules/2.4.20-18.7-e-smith/kernel/drivers/net/bsd_comp.o
/lib/modules/2.4.20-18.7-e-smith/kernel/drivers/net/ppp_generic.o
/lib/modules/2.4.20-18.7-e-smith/kernel/drivers/net/ppp_mppe.o
/lib/modules/2.4.20-18.7smp-e-smith/kernel/drivers/net/bsd_comp.o
/lib/modules/2.4.20-18.7smp-e-smith/kernel/drivers/net/ppp_generic.o
/lib/modules/2.4.20-18.7smp-e-smith/kernel/drivers/net/ppp_mppe.o
so it would appear that this provides what is needed at least for i686 uniprocesser systems.
From the page it seems that all that is needed is:
# rpm -ivh kernel-mppe-*.rpm
# depmod -a
but I cannot test it.
Has anybody upgraded to this (2.4.20-30.7.legacy) kernel, and has PPTP VPN working?
I would like to add this info if someone can verify that it works.