The tunnel source and the destination addresses do not support VRF.
GRE tunnels support only OSPF, ISIS, and BGP.
QoS mutation configuration on the VE is not
supported, including VEs that are bound to GRE tunnels.
The maximum number of GRE tunnels supported is 256.
The routing protocol used for resolving the GRE
tunnel destination cannot be configured under the VE that is bound to the GRE
tunnel.
GRE tunnels do not support IPv6.
GRE keep-alive is supported only with the default VRF. If you want GRE keep-alive
in the non-default VRF, configure a static route in the VRF context to reach the
GRE tunnel source.
