libvirt-0.8.1-13.el6.x86_64

[root@rhel6 ~]# sysctl net.ipv4.ip_forward
net.ipv4.ip_forward = 1
[root@rhel6 ~]# tuned-adm profile default
Stopping tuned:                                            [  OK  ]
Switching to profile 'default'
Applying ktune sysctl settings:
/etc/ktune.d/tunedadm.conf:                                [  OK  ]
Applying sysctl settings from /etc/sysctl.conf
Starting tuned:                                            [  OK  ]
[root@rhel6 ~]# sysctl net.ipv4.ip_forward
net.ipv4.ip_forward = 0

The same thing happens if, for example, your machine boots with NetworkManager disabled, and you later enable NetworkManager. If libvirtd started at boot time, it would have turned ip_forwarding on, but enabling NetworkManager turns it off.

Should libvirt be making this change permanent as a routine part of starting up libvirtd? Or should we instead not touch it at all, and tell the user that they need to change their configuration outside the context of libvirt?

This issue has been proposed when we are only considering blocker
issues in the current Red Hat Enterprise Linux release. It has
been denied for the current Red Hat Enterprise Linux release.

** If you would still like this issue considered for the current
release, ask your support representative to file as a blocker on
your behalf. Otherwise ask that it be considered for the next
Red Hat Enterprise Linux release. **