How to setup veth with 9000 MTU to simulate sending and receiving large UDP multicast packets on the same host?

The sender needs to transmit large data packets to the receiver (which is on the same host with 1500 MTU) and I think this can be simulated using veth with 9000 MTU, from my reading on it. But I'm not able to figure out how exactly to do that - most of the veth tutorials/articles on the internet mention network namespaces and I'm not sure if I would need to create a network namespace to achieve this. Any pointers/suggestions would be helpful, thanks!