When attempting to send transactions to the TPU from a Rust client using a TpuClient connection, I am encountering the following error:

panicked at 'QuicLazyInitializedEndpoint::create_endpoint bind_in_range: Custom { kind: Other, error: "No available UDP ports in (8000, 10000)" }

Any insight as to what is happening here? From what I can gather, RPCs compete for a limited number of QUIC connections on the validators. Would this potentially suggest that there was high demand during this specific slot and so a connection was not able to be made? Any other ideas? And any ideas on how to get around this?

1 Answer 1


Your client is trying to send to the old TPU port, which used to accept UDP. Now you must configure your client to use QUIC.

That code has changed a lot recently, so the easiest thing might be to update your crates to version 1.14, which defaults to using QUIC everywhere.

  • I am still getting the same error despite using crate version 1.14. It is pointing to this line of code: docs.rs/solana-client/latest/src/solana_client/nonblocking/… The error is occuring when this function is called: solana_net_utils::bind_in_range, which is defined here: docs.rs/solana-net-utils/latest/src/solana_net_utils/…. It looks like that always returns a UdpSocket. I guess QUIC is still using UDP sockets then right? Any other thoughts on what might be occurring here?
    – guillermo
    Jan 12, 2023 at 17:13
  • Yeah correct, it's using a UDP socket under the hood, so this points to an issue in your testing machine, since it's failing to bind to a port. Do you have networking privileges on that machine?
    – Jon C
    Jan 12, 2023 at 20:33
  • Yeah this error doesn't occur immediately, it usually occurs after a while. My guess was that as I am connecting from an RPC that isn't a staked validator, I am getting booted out of the 500 available QUIC ports due to high demand for connections.
    – guillermo
    Jan 13, 2023 at 1:07
  • You may be creating too many TPU clients in that case. Have you tried creating one and then reusing that for the whole of your run?
    – Jon C
    Jan 13, 2023 at 13:07
  • Yeah I just create one TPU client and use it across various threads as needed.
    – guillermo
    Jan 13, 2023 at 17:12

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