diff --git a/test/functional/feature_bind_extra.py b/test/functional/feature_bind_extra.py
--- a/test/functional/feature_bind_extra.py
+++ b/test/functional/feature_bind_extra.py
@@ -11,7 +11,7 @@
 
 from test_framework.netutil import addr_to_hex, get_bind_addrs
 from test_framework.test_framework import BitcoinTestFramework, SkipTest
-from test_framework.util import PORT_MIN, PORT_RANGE, assert_equal, rpc_port
+from test_framework.util import assert_equal, p2p_port, rpc_port
 
 
 class BindExtraTest(BitcoinTestFramework):
@@ -23,11 +23,6 @@
         self.num_nodes = 2
 
     def setup_network(self):
-        # Override setup_network() because we want to put the result of
-        # p2p_port() in self.extra_args[], before the nodes are started.
-        # p2p_port() is not usable in set_test_params() because PortSeed.n is
-        # not set at that time.
-
         # Due to OS-specific network stats queries, we only run on Linux.
         self.log.info("Checking for Linux")
         if not sys.platform.startswith('linux'):
@@ -35,8 +30,8 @@
 
         loopback_ipv4 = addr_to_hex("127.0.0.1")
 
-        # Start custom ports after p2p and rpc ports.
-        port = PORT_MIN + 2 * PORT_RANGE
+        # Start custom ports by reusing unused p2p ports
+        port = p2p_port(self.num_nodes)
 
         # Array of tuples [command line arguments, expected bind addresses].
         self.expected = []
diff --git a/test/functional/feature_proxy.py b/test/functional/feature_proxy.py
--- a/test/functional/feature_proxy.py
+++ b/test/functional/feature_proxy.py
@@ -30,7 +30,6 @@
 - Test getnetworkinfo for each node
 """
 
-import os
 import socket
 
 from test_framework.netutil import test_ipv6_local
@@ -41,9 +40,7 @@
     Socks5Server,
 )
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import PORT_MIN, PORT_RANGE, assert_equal
-
-RANGE_BEGIN = PORT_MIN + 2 * PORT_RANGE  # Start after p2p and rpc ports
+from test_framework.util import assert_equal, p2p_port
 
 # Networks returned by RPC getpeerinfo.
 NET_UNROUTABLE = "not_publicly_routable"
@@ -67,21 +64,19 @@
         # Create two proxies on different ports
         # ... one unauthenticated
         self.conf1 = Socks5Configuration()
-        self.conf1.addr = ('127.0.0.1', RANGE_BEGIN + (os.getpid() % 1000))
+        self.conf1.addr = ('127.0.0.1', p2p_port(self.num_nodes))
         self.conf1.unauth = True
         self.conf1.auth = False
         # ... one supporting authenticated and unauthenticated (Tor)
         self.conf2 = Socks5Configuration()
-        self.conf2.addr = (
-            '127.0.0.1', RANGE_BEGIN + 1000 + (os.getpid() % 1000))
+        self.conf2.addr = ('127.0.0.1', p2p_port(self.num_nodes + 1))
         self.conf2.unauth = True
         self.conf2.auth = True
         if self.have_ipv6:
             # ... one on IPv6 with similar configuration
             self.conf3 = Socks5Configuration()
             self.conf3.af = socket.AF_INET6
-            self.conf3.addr = (
-                '::1', RANGE_BEGIN + 2000 + (os.getpid() % 1000))
+            self.conf3.addr = ('::1', p2p_port(self.num_nodes + 2))
             self.conf3.unauth = True
             self.conf3.auth = True
         else:
diff --git a/test/functional/p2p_getaddr_caching.py b/test/functional/p2p_getaddr_caching.py
--- a/test/functional/p2p_getaddr_caching.py
+++ b/test/functional/p2p_getaddr_caching.py
@@ -38,6 +38,9 @@
 class AddrTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
+        # TODO When Backporting core#25096, please also includes changes from:
+        #  - core#25312
+        #  - core#25333
 
     def run_test(self):
         self.log.info('Fill peer AddrMan with a lot of records')
diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -205,10 +205,10 @@
         self.add_options(parser)
         self.options = parser.parse_args()
 
-    def setup(self):
-        """Call this method to start up the test framework object with options set."""
         PortSeed.n = self.options.port_seed
 
+    def setup(self):
+        """Call this method to start up the test framework object with options set."""
         check_json_precision()
 
         self.options.cachedir = os.path.abspath(self.options.cachedir)