diff --git a/doc/release-notes.md b/doc/release-notes.md
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -25,4 +25,7 @@
      [test]
      mempoolsize=200
      [regtest]
-     mempoolsize=50
\ No newline at end of file
+     mempoolsize=50
+   The `addnode=`, `connect=`, `port=`, `bind=`, `rpcport=`, `rpcbind=`
+   and `wallet=` options will only apply to mainnet when specified in the
+   configuration file, unless a network is specified.
\ No newline at end of file
diff --git a/src/init.cpp b/src/init.cpp
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1262,6 +1262,11 @@
                       __func__);
         }
     }
+
+    // Warn if network-specific options (-addnode, -connect, etc) are
+    // specified in default section of config file, but not overridden
+    // on the command line or in this network's section of the config file.
+    gArgs.WarnForSectionOnlyArgs();
 }
 
 static std::string ResolveErrMsg(const char *const optname,
diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -170,6 +170,7 @@
 }
 
 struct TestArgsManager : public ArgsManager {
+    TestArgsManager() { m_network_only_args.clear(); }
     std::map<std::string, std::vector<std::string>> &GetOverrideArgs() {
         return m_override_args;
     }
@@ -184,6 +185,10 @@
         }
         ReadConfigStream(streamConfig);
     }
+    void SetNetworkOnlyArg(const std::string arg) {
+        LOCK(cs_args);
+        m_network_only_args.insert(arg);
+    }
 };
 
 BOOST_AUTO_TEST_CASE(util_ParseParameters) {
@@ -317,6 +322,7 @@
                              "\n"
                              "[sec1]\n"
                              "ccc=extend2\n"
+                             "d=eee\n"
                              "h=1\n"
                              "[sec2]\n"
                              "ccc=extend3\n"
@@ -326,10 +332,10 @@
 
     test_args.ReadConfigString(str_config);
     // expectation: a, b, ccc, d, fff, ggg, h, i end up in map
-    // so do sec1.ccc, sec1.h, sec2.ccc, sec2.iii
+    // so do sec1.ccc, sec1.d, sec1.h, sec2.ccc, sec2.iii
 
     BOOST_CHECK(test_args.GetOverrideArgs().empty());
-    BOOST_CHECK(test_args.GetConfigArgs().size() == 12);
+    BOOST_CHECK(test_args.GetConfigArgs().size() == 13);
 
     BOOST_CHECK(test_args.GetConfigArgs().count("-a") &&
                 test_args.GetConfigArgs().count("-b") &&
@@ -411,11 +417,12 @@
     // same as original
     BOOST_CHECK(test_args.GetArg("-a", "xxx") == "" &&
                 test_args.GetArg("-b", "xxx") == "1" &&
-                test_args.GetArg("-d", "xxx") == "e" &&
                 test_args.GetArg("-fff", "xxx") == "0" &&
                 test_args.GetArg("-ggg", "xxx") == "1" &&
                 test_args.GetArg("-zzz", "xxx") == "xxx" &&
                 test_args.GetArg("-iii", "xxx") == "xxx");
+    // d is overridden
+    BOOST_CHECK(test_args.GetArg("-d", "xxx") == "eee");
     // section-specific setting
     BOOST_CHECK(test_args.GetArg("-h", "xxx") == "1");
     // section takes priority for multiple values
@@ -449,6 +456,29 @@
     BOOST_CHECK_EQUAL_COLLECTIONS(sec2_ccc_res.begin(), sec2_ccc_res.end(),
                                   sec2_ccc_expected.begin(),
                                   sec2_ccc_expected.end());
+
+    // Test section only options
+
+    test_args.SetNetworkOnlyArg("-d");
+    test_args.SetNetworkOnlyArg("-ccc");
+    test_args.SetNetworkOnlyArg("-h");
+
+    test_args.SelectConfigNetwork(CBaseChainParams::MAIN);
+    BOOST_CHECK(test_args.GetArg("-d", "xxx") == "e");
+    BOOST_CHECK(test_args.GetArgs("-ccc").size() == 2);
+    BOOST_CHECK(test_args.GetArg("-h", "xxx") == "0");
+
+    test_args.SelectConfigNetwork("sec1");
+    BOOST_CHECK(test_args.GetArg("-d", "xxx") == "eee");
+    BOOST_CHECK(test_args.GetArgs("-d").size() == 1);
+    BOOST_CHECK(test_args.GetArgs("-ccc").size() == 2);
+    BOOST_CHECK(test_args.GetArg("-h", "xxx") == "1");
+
+    test_args.SelectConfigNetwork("sec2");
+    BOOST_CHECK(test_args.GetArg("-d", "xxx") == "xxx");
+    BOOST_CHECK(test_args.GetArgs("-d").size() == 0);
+    BOOST_CHECK(test_args.GetArgs("-ccc").size() == 1);
+    BOOST_CHECK(test_args.GetArg("-h", "xxx") == "0");
 }
 
 BOOST_AUTO_TEST_CASE(util_GetArg) {
diff --git a/src/util.h b/src/util.h
--- a/src/util.h
+++ b/src/util.h
@@ -25,6 +25,7 @@
 #include <cstdint>
 #include <exception>
 #include <map>
+#include <set>
 #include <string>
 #include <unordered_set>
 #include <vector>
@@ -101,9 +102,13 @@
     std::map<std::string, std::vector<std::string>> m_override_args;
     std::map<std::string, std::vector<std::string>> m_config_args;
     std::string m_network;
+    std::set<std::string> m_network_only_args;
+
     void ReadConfigStream(std::istream &stream);
 
 public:
+    ArgsManager();
+
     /**
      * Select the network in use
      */
@@ -112,6 +117,13 @@
     void ParseParameters(int argc, const char *const argv[]);
     void ReadConfigFile(const std::string &confPath);
 
+    /**
+     * Log warnings for options in m_section_only_args when they are specified
+     * in the default section but not overridden on the command line or in a
+     * network-specific section in the config file.
+     */
+    void WarnForSectionOnlyArgs();
+
     /**
      * Return a vector of strings of the given argument
      *
diff --git a/src/util.cpp b/src/util.cpp
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -173,6 +173,14 @@
 public:
     typedef std::map<std::string, std::vector<std::string>> MapArgs;
 
+    /** Determine whether to use config settings in the default section,
+     *  See also comments around ArgsManager::ArgsManager() below. */
+    static inline bool UseDefaultSection(const ArgsManager &am,
+                                         const std::string &arg) {
+        return (am.m_network == CBaseChainParams::MAIN ||
+                am.m_network_only_args.count(arg) == 0);
+    }
+
     /** Convert regular argument into the network-specific setting */
     static inline std::string NetworkArg(const ArgsManager &am,
                                          const std::string &arg) {
@@ -238,9 +246,11 @@
             }
         }
 
-        found_result = GetArgHelper(am.m_config_args, arg);
-        if (found_result.first) {
-            return found_result;
+        if (UseDefaultSection(am, arg)) {
+            found_result = GetArgHelper(am.m_config_args, arg);
+            if (found_result.first) {
+                return found_result;
+            }
         }
 
         return found_result;
@@ -292,6 +302,59 @@
     return false;
 }
 
+ArgsManager::ArgsManager()
+    : /* These options would cause cross-contamination if values for mainnet
+       * were used while running on regtest/testnet (or vice-versa).
+       * Setting them as section_only_args ensures that sharing a config file
+       * between mainnet and regtest/testnet won't cause problems due to these
+       * parameters by accident. */
+      m_network_only_args{
+          "-addnode", "-connect", "-port",   "-bind",
+          "-rpcport", "-rpcbind", "-wallet",
+      } {
+    // nothing to do
+}
+
+void ArgsManager::WarnForSectionOnlyArgs() {
+    // if there's no section selected, don't worry
+    if (m_network.empty()) {
+        return;
+    }
+
+    // if it's okay to use the default section for this network, don't worry
+    if (m_network == CBaseChainParams::MAIN) {
+        return;
+    }
+
+    for (const auto &arg : m_network_only_args) {
+        std::pair<bool, std::string> found_result;
+
+        // if this option is overridden it's fine
+        found_result = ArgsManagerHelper::GetArgHelper(m_override_args, arg);
+        if (found_result.first) {
+            continue;
+        }
+
+        // if there's a network-specific value for this option, it's fine
+        found_result = ArgsManagerHelper::GetArgHelper(
+            m_config_args, ArgsManagerHelper::NetworkArg(*this, arg));
+        if (found_result.first) {
+            continue;
+        }
+
+        // if there isn't a default value for this option, it's fine
+        found_result = ArgsManagerHelper::GetArgHelper(m_config_args, arg);
+        if (!found_result.first) {
+            continue;
+        }
+
+        // otherwise, issue a warning
+        LogPrintf("Warning: Config setting for %s only applied on %s network "
+                  "when in [%s] section.\n",
+                  arg, m_network, m_network);
+    }
+}
+
 void ArgsManager::SelectConfigNetwork(const std::string &network) {
     m_network = network;
 }
@@ -341,13 +404,18 @@
     }
 
     LOCK(cs_args);
+
     ArgsManagerHelper::AddArgs(result, m_override_args, strArg);
     if (!m_network.empty()) {
         ArgsManagerHelper::AddArgs(
             result, m_config_args,
             ArgsManagerHelper::NetworkArg(*this, strArg));
     }
-    ArgsManagerHelper::AddArgs(result, m_config_args, strArg);
+
+    if (ArgsManagerHelper::UseDefaultSection(*this, strArg)) {
+        ArgsManagerHelper::AddArgs(result, m_config_args, strArg);
+    }
+
     return result;
 }