GRE Configuration Considerations

The GRE feature has some limitations and restrictions that you should understand before you configure it.

• 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.
• GRE tunnels are not supported in SLX9150/9250.