Installation guide

Enabling IP forwarding (net.ipv4.ip_forward = 1) is required for virtual bridge devices.
Note that installing libvirt enables this variable so it will be enabled when the virtualization
packages are installed unless it was manually disabled.
Note
Note that enabling IP forwarding is n o t required for physical bridge devices. When a guest is
connected through a physical bridge, traffic only operates at a level that does not require IP
configuration such as IP forwarding.
Red Hat En t erp rise Lin ux 5 Virt ualizat ion Guid e
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