diff --git a/Cargo.lock b/Cargo.lock
index c3e87c1..5059838 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -12,6 +12,15 @@ version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "130aac562c0dd69c56b3b1cc8ffd2e17be31d0b6c25b61c96b76231aa23e39e1"
 
+[[package]]
+name = "c2-chacha"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "214238caa1bf3a496ec3392968969cab8549f96ff30652c9e56885329315f6bb"
+dependencies = [
+ "ppv-lite86",
+]
+
 [[package]]
 name = "cfg-if"
 version = "0.1.10"
@@ -34,10 +43,22 @@ version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 
+[[package]]
+name = "getrandom"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7abc8dd8451921606d809ba32e95b6111925cd2906060d2dcc29c070220503eb"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
 [[package]]
 name = "hptp"
 version = "0.1.0"
 dependencies = [
+ "rand",
  "tokio",
 ]
 
@@ -153,6 +174,12 @@ version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "237844750cfbb86f67afe27eee600dfbbcb6188d734139b534cbfbf4f96792ae"
 
+[[package]]
+name = "ppv-lite86"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "74490b50b9fbe561ac330df47c08f3f33073d2d00c150f719147d7c54522fa1b"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.9"
@@ -171,6 +198,47 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rand"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
+dependencies = [
+ "getrandom",
+ "libc",
+ "rand_chacha",
+ "rand_core",
+ "rand_hc",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "03a2a90da8c7523f554344f921aa97283eadf6ac484a6d2a7d0212fa7f8d6853"
+dependencies = [
+ "c2-chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+dependencies = [
+ "rand_core",
+]
+
 [[package]]
 name = "slab"
 version = "0.4.2"
@@ -227,6 +295,12 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
 
+[[package]]
+name = "wasi"
+version = "0.9.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
+
 [[package]]
 name = "winapi"
 version = "0.2.8"
diff --git a/hptp-recv/src/main.rs b/hptp-recv/src/main.rs
index 9a19540..361dc16 100644
--- a/hptp-recv/src/main.rs
+++ b/hptp-recv/src/main.rs
@@ -5,8 +5,7 @@ extern crate tokio;
 extern crate thiserror;
 
 use hptp::log::Logger;
-use std::net::Ipv4Addr;
-use tokio::net::UdpSocket;
+// use tokio::net::UdpSocket;
 
 #[derive(Error, Debug)]
 enum Error {
@@ -37,7 +36,9 @@ fn main() {
 }
 
 async fn start(log: &mut Logger) -> Result<(), Error> {
-    let sock = udp_listen_or_retry(3700, 4).await?;
+    let sock = hptp::udp_retrying_bind(16, hptp::random_port)
+        .await
+        .map_err(|_| Error::NoPortAvail)?;
     log.bound(sock.local_addr()?.port()).await;
 
     let (mut rx, _tx) = sock.split();
@@ -51,13 +52,3 @@ async fn start(log: &mut Logger) -> Result<(), Error> {
         .await;
     }
 }
-
-async fn udp_listen_or_retry(init_port: u16, max_tries: u16) -> Result<UdpSocket, Error> {
-    for tries in 0..max_tries {
-        let port = init_port + tries;
-        if let Ok(sock) = UdpSocket::bind((Ipv4Addr::LOCALHOST, port)).await {
-            return Ok(sock);
-        }
-    }
-    Err(Error::NoPortAvail)
-}
diff --git a/hptp/Cargo.toml b/hptp/Cargo.toml
index 613a9b8..4f06334 100644
--- a/hptp/Cargo.toml
+++ b/hptp/Cargo.toml
@@ -8,4 +8,5 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-tokio = {version = "0.2.*", features = ["io-std", "io-util"]}
+tokio = {version = "0.2.*", features = ["io-std", "io-util", "udp"]}
+rand = "0.7.*"
\ No newline at end of file
diff --git a/hptp/src/lib.rs b/hptp/src/lib.rs
index 6e5efe4..a510249 100644
--- a/hptp/src/lib.rs
+++ b/hptp/src/lib.rs
@@ -1,4 +1,24 @@
-pub const SEND_GREETING: &'static str = "*pat*";
-pub const RECV_GREETING: &'static str = "owo";
+extern crate rand;
 
 pub mod log;
+
+use std::net::Ipv4Addr;
+use tokio::net::UdpSocket;
+
+pub async fn udp_retrying_bind<F>(max_tries: usize, mut pick_port: F) -> Result<UdpSocket, ()>
+where
+    F: FnMut() -> u16,
+{
+    for _ in 0..max_tries {
+        let port = pick_port();
+        if let Ok(sock) = UdpSocket::bind((Ipv4Addr::LOCALHOST, port)).await {
+            return Ok(sock);
+        }
+    }
+    Err(())
+}
+
+pub fn random_port() -> u16 {
+    use rand::distributions::{Distribution, Uniform};
+    Uniform::new(1025, 65535u16).sample(&mut rand::thread_rng())
+}