veth interfaces performance problem

On a fast AWS machine (m5.2xlarge), I am creating around 600 veth interfaces, each one having a little server (with socat) running on a port. I then start sending around 7kb/second of data per server. When sending to about 500 servers everything goes well, but when I send it to around 600 servers, timeouts begin to occur. The connection to the server can take more than 3 seconds to be executed, as I have tested. It's not a lot of processing (for such a server) and it's not a lot of data. *Is the Linux veth implementation slow?* I have created a [git repo to reproduce the problem](https://github.com/pallix/veth_network_namespaces_perf) . Any help would be highly appreciated.