Hello, My problem was solved by the excellent support of the openswan people (Paul Wouters). If other people run into the same problem, this whas the solution: I wanted to keep the stock kernel but wanted KLIPS, I don't need NAT-Traversal When the current release is used (2.4.6rc5) the module caused a kernel panic when unloading (that means also rebooting) the system. A bad thing for a firewall that is probably locked somewhere in a closet. The current CVS version contains the fix for the unload bug. The CVS version can be retrieved by: cd /usr/src rm -rf openswan-2 cvs -d :pserver:anoncvs at anoncvs.openswan.org:/public/cvs login cvs -d :pserver:anoncvs at anoncvs.openswan.org:/public/cvs co openswan-2 Then edit /usr/src/openswan-2/packaging/linus/config-all.h and change the define for NAT_TRAVERSAL for 1 to 0 Compile the programs and module with: make KERNELSRC=/lib/modules/`uname -r`/build programs module make KERNELSRC=/lib/modules/`uname -r`/build install minstall This solved the problem for me Bas