diff --git a/cli/tests/echo_server.ts b/cli/tests/echo_server.ts
index 48b43aca6f8757..ab29f775fc9142 100644
--- a/cli/tests/echo_server.ts
+++ b/cli/tests/echo_server.ts
@@ -1,4 +1,4 @@
-const addr = Deno.args[1] || "0.0.0.0:4544";
+const addr = Deno.args[0] || "0.0.0.0:4500";
 const [hostname, port] = addr.split(":");
 const listener = Deno.listen({ hostname, port: Number(port) });
 console.log("listening on", addr);
diff --git a/tools/http_benchmark.py b/tools/http_benchmark.py
index 2c6c8d60e0c8bb..366ab48cee295f 100755
--- a/tools/http_benchmark.py
+++ b/tools/http_benchmark.py
@@ -14,54 +14,40 @@
 #   "deno_http" was once called "deno_net_http"
 
 DURATION = "20s"
-NEXT_PORT = 4544
-
-
-def server_addr(port):
-    return "0.0.0.0:%s" % port
-
-
-def get_port():
-    global NEXT_PORT
-    port = NEXT_PORT
-    NEXT_PORT += 1
-    # Return port as str because all usages below are as a str and having it an
-    # integer just adds complexity.
-    return str(port)
 
 
 def deno_tcp(deno_exe):
-    port = get_port()
+    port = util.get_port()
     deno_cmd = [
         # TODO(lucacasonato): remove unstable when stabilized
         deno_exe,
         "run",
         "--allow-net",
         "tools/deno_tcp.ts",
-        server_addr(port)
+        util.server_addr(port)
     ]
     print "http_benchmark testing DENO tcp."
     return run(deno_cmd, port)
 
 
 def deno_http(deno_exe):
-    port = get_port()
+    port = util.get_port()
     deno_cmd = [
         deno_exe, "run", "--allow-net", "--reload", "--unstable",
         "std/http/http_bench.ts",
-        server_addr(port)
+        util.server_addr(port)
     ]
     print "http_benchmark testing DENO using net/http."
     return run(deno_cmd, port)
 
 
 def deno_tcp_proxy(deno_exe, hyper_hello_exe):
-    port = get_port()
-    origin_port = get_port()
+    port = util.get_port()
+    origin_port = util.get_port()
     deno_cmd = [
         deno_exe, "run", "--allow-net", "tools/deno_tcp_proxy.ts",
-        server_addr(port),
-        server_addr(origin_port)
+        util.server_addr(port),
+        util.server_addr(origin_port)
     ]
     print "http_proxy_benchmark testing DENO using net/tcp."
     return run(
@@ -71,12 +57,12 @@ def deno_tcp_proxy(deno_exe, hyper_hello_exe):
 
 
 def deno_http_proxy(deno_exe, hyper_hello_exe):
-    port = get_port()
-    origin_port = get_port()
+    port = util.get_port()
+    origin_port = util.get_port()
     deno_cmd = [
         deno_exe, "run", "--allow-net", "tools/deno_http_proxy.ts",
-        server_addr(port),
-        server_addr(origin_port)
+        util.server_addr(port),
+        util.server_addr(origin_port)
     ]
     print "http_proxy_benchmark testing DENO using net/http."
     return run(
@@ -91,15 +77,15 @@ def deno_core_http_bench(exe):
 
 
 def node_http():
-    port = get_port()
+    port = util.get_port()
     node_cmd = ["node", "tools/node_http.js", port]
     print "http_benchmark testing NODE."
     return run(node_cmd, port)
 
 
 def node_http_proxy(hyper_hello_exe):
-    port = get_port()
-    origin_port = get_port()
+    port = util.get_port()
+    origin_port = util.get_port()
     node_cmd = ["node", "tools/node_http_proxy.js", port, origin_port]
     print "http_proxy_benchmark testing NODE."
     return run(node_cmd, port, None,
@@ -107,8 +93,8 @@ def node_http_proxy(hyper_hello_exe):
 
 
 def node_tcp_proxy(hyper_hello_exe):
-    port = get_port()
-    origin_port = get_port()
+    port = util.get_port()
+    origin_port = util.get_port()
     node_cmd = ["node", "tools/node_tcp_proxy.js", port, origin_port]
     print "http_proxy_benchmark testing NODE tcp."
     return run(node_cmd, port, None,
@@ -116,7 +102,7 @@ def node_tcp_proxy(hyper_hello_exe):
 
 
 def node_tcp():
-    port = get_port()
+    port = util.get_port()
     node_cmd = ["node", "tools/node_tcp.js", port]
     print "http_benchmark testing node_tcp.js"
     return run(node_cmd, port)
@@ -127,7 +113,7 @@ def http_proxy_origin(hyper_hello_exe, port):
 
 
 def hyper_http(hyper_hello_exe):
-    port = get_port()
+    port = util.get_port()
     hyper_cmd = [hyper_hello_exe, port]
     print "http_benchmark testing RUST hyper."
     return run(hyper_cmd, port)
diff --git a/tools/throughput_benchmark.py b/tools/throughput_benchmark.py
index 7094c37cea9605..68defe4c639528 100755
--- a/tools/throughput_benchmark.py
+++ b/tools/throughput_benchmark.py
@@ -13,8 +13,7 @@
 import util
 
 MB = 1024 * 1024
-SERVER_ADDR = "0.0.0.0:4544"
-CLIENT_ADDR = "127.0.0.1 4544"
+CLIENT_ADDR = "127.0.0.1"
 
 
 def cat(deno_exe, megs):
@@ -30,9 +29,11 @@ def cat(deno_exe, megs):
 
 def tcp(deno_exe, megs):
     size = megs * MB
+    port = util.get_port()
+    server_addr = util.server_addr(port)
     # Run deno echo server in the background.
     args = [
-        deno_exe, "run", "--allow-net", "cli/tests/echo_server.ts", SERVER_ADDR
+        deno_exe, "run", "--allow-net", "cli/tests/echo_server.ts", server_addr
     ]
     print args
     echo_server = subprocess.Popen(args)
@@ -40,7 +41,7 @@ def tcp(deno_exe, megs):
     time.sleep(5)  # wait for deno to wake up. TODO racy.
     try:
         start = time.time()
-        nc_cmd = "nc -N " + CLIENT_ADDR
+        nc_cmd = "nc %s %s" % (CLIENT_ADDR, port)
         cmd = ("head -c %s /dev/zero " % size) + " | " + nc_cmd
         print cmd
         subprocess.check_output(cmd, shell=True)
diff --git a/tools/util.py b/tools/util.py
index e5dcaccce016d8..47887c253f6c12 100644
--- a/tools/util.py
+++ b/tools/util.py
@@ -428,3 +428,19 @@ def tty_capture(cmd, bytes_input, timeout=5):
 def print_command(cmd, files):
     noun = "file" if len(files) == 1 else "files"
     print "%s (%d %s)" % (cmd, len(files), noun)
+
+
+NEXT_PORT = 4544
+
+
+def get_port():
+    global NEXT_PORT
+    port = NEXT_PORT
+    NEXT_PORT += 1
+    # Return port as str because all usages below are as a str and having it an
+    # integer just adds complexity.
+    return str(port)
+
+
+def server_addr(port):
+    return "0.0.0.0:%s" % port