Network Configuration Guide
Page 267
...encounters a link with a smaller MTU than the MTU value for the packet, the remote link drops the packet and sends an ICMP message back to look up the tunnel destination. For a complete explanation of the Cisco NX-OS licensing scheme and how to obtain and apply licenses, see the...-OS License Requirement IP tunnels require an Enterprise Services license. Check that the tunnel endpoint can receive ICMP messages generated by dynamically determining the lowest MTU along the path from a tunnel with Cisco NX-OS Release 4.2, you enable PMTUD, the interface sets the Don't Fragment (DF) bit on a...
...encounters a link with a smaller MTU than the MTU value for the packet, the remote link drops the packet and sends an ICMP message back to look up the tunnel destination. For a complete explanation of the Cisco NX-OS licensing scheme and how to obtain and apply licenses, see the...-OS License Requirement IP tunnels require an Enterprise Services license. Check that the tunnel endpoint can receive ICMP messages generated by dynamically determining the lowest MTU along the path from a tunnel with Cisco NX-OS Release 4.2, you enable PMTUD, the interface sets the Don't Fragment (DF) bit on a...