diff --git a/src/net.h b/src/net.h
--- a/src/net.h
+++ b/src/net.h
@@ -494,7 +494,7 @@
 bool IsLimited(const CNetAddr &addr);
 bool AddLocal(const CService &addr, int nScore = LOCAL_NONE);
 bool AddLocal(const CNetAddr &addr, int nScore = LOCAL_NONE);
-bool RemoveLocal(const CService &addr);
+void RemoveLocal(const CService &addr);
 bool SeenLocal(const CService &addr);
 bool IsLocal(const CService &addr);
 bool GetLocal(CService &addr, const CNetAddr *paddrPeer = nullptr);
diff --git a/src/net.cpp b/src/net.cpp
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -135,11 +135,10 @@
     const int64_t nOneWeek = 7 * 24 * 60 * 60;
     std::vector<CAddress> vSeedsOut;
     vSeedsOut.reserve(vSeedsIn.size());
-    for (std::vector<SeedSpec6>::const_iterator i(vSeedsIn.begin());
-         i != vSeedsIn.end(); ++i) {
+    for (const auto &seed_in : vSeedsIn) {
         struct in6_addr ip;
-        memcpy(&ip, i->addr, sizeof(ip));
-        CAddress addr(CService(ip, i->port), NODE_NETWORK);
+        memcpy(&ip, seed_in.addr, sizeof(ip));
+        CAddress addr(CService(ip, seed_in.port), NODE_NETWORK);
         addr.nTime = GetTime() - GetRand(nOneWeek) - nOneWeek;
         vSeedsOut.push_back(addr);
     }
@@ -160,7 +159,7 @@
     return ret;
 }
 
-int GetnScore(const CService &addr) {
+static int GetnScore(const CService &addr) {
     LOCK(cs_mapLocalHost);
     if (mapLocalHost.count(addr) == LOCAL_NONE) {
         return 0;
@@ -230,11 +229,10 @@
     return AddLocal(CService(addr, GetListenPort()), nScore);
 }
 
-bool RemoveLocal(const CService &addr) {
+void RemoveLocal(const CService &addr) {
     LOCK(cs_mapLocalHost);
     LogPrintf("RemoveLocal(%s)\n", addr.ToString());
     mapLocalHost.erase(addr);
-    return true;
 }
 
 /**
@@ -288,7 +286,7 @@
 CNode *CConnman::FindNode(const CNetAddr &ip) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
-        if ((CNetAddr)pnode->addr == ip) {
+        if (static_cast<CService>(pnode->addr) == ip) {
             return pnode;
         }
     }
@@ -298,7 +296,7 @@
 CNode *CConnman::FindNode(const CSubNet &subNet) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
-        if (subNet.Match((CNetAddr)pnode->addr)) {
+        if (subNet.Match(static_cast<CNetAddr>(pnode->addr))) {
             return pnode;
         }
     }
@@ -318,7 +316,7 @@
 CNode *CConnman::FindNode(const CService &addr) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
-        if ((CService)pnode->addr == addr) {
+        if (static_cast<CNetAddr>(pnode->addr) == addr) {
             return pnode;
         }
     }
@@ -327,7 +325,7 @@
 
 bool CConnman::CheckIncomingNonce(uint64_t nonce) {
     LOCK(cs_vNodes);
-    for (CNode *pnode : vNodes) {
+    for (const CNode *pnode : vNodes) {
         if (!pnode->fSuccessfullyConnected && !pnode->fInbound &&
             pnode->GetLocalNonce() == nonce)
             return false;
@@ -359,7 +357,7 @@
         }
 
         // Look for an existing connection
-        CNode *pnode = FindNode((CService)addrConnect);
+        CNode *pnode = FindNode(static_cast<CService>(addrConnect));
         if (pnode) {
             LogPrintf("Failed to open new connection, already connected\n");
             return nullptr;
@@ -374,7 +372,7 @@
                  : (double)(GetAdjustedTime() - addrConnect.nTime) / 3600.0);
 
     // Connect
-    SOCKET hSocket;
+    SOCKET hSocket = INVALID_SOCKET;
     bool proxyConnectionFailed = false;
     if (pszDest ? ConnectSocketByName(addrConnect, hSocket, pszDest,
                                       config->GetChainParams().GetDefaultPort(),
@@ -395,7 +393,7 @@
             // the name we used to connect in that CNode, so that future
             // FindNode() calls to that name catch this early.
             LOCK(cs_vNodes);
-            CNode *pnode = FindNode((CService)addrConnect);
+            CNode *pnode = FindNode(static_cast<CService>(addrConnect));
             if (pnode) {
                 pnode->MaybeSetAddrName(std::string(pszDest));
                 CloseSocket(hSocket);
@@ -1122,10 +1120,9 @@
     // Disconnect from the network group with the most connections
     NodeId evicted = vEvictionCandidates.front().id;
     LOCK(cs_vNodes);
-    for (std::vector<CNode *>::const_iterator it(vNodes.begin());
-         it != vNodes.end(); ++it) {
-        if ((*it)->GetId() == evicted) {
-            (*it)->fDisconnect = true;
+    for (CNode *pnode : vNodes) {
+        if (pnode->GetId() == evicted) {
+            pnode->fDisconnect = true;
             return true;
         }
     }
@@ -1150,7 +1147,7 @@
     bool whitelisted = hListenSocket.whitelisted || IsWhitelistedRange(addr);
     {
         LOCK(cs_vNodes);
-        for (CNode *pnode : vNodes) {
+        for (const CNode *pnode : vNodes) {
             if (pnode->fInbound) {
                 nInbound++;
             }
@@ -1518,8 +1515,8 @@
                                   (GetTimeMicros() - pnode->nPingUsecStart));
                     pnode->fDisconnect = true;
                 } else if (!pnode->fSuccessfullyConnected) {
-                    LogPrintf("version handshake timeout from %d\n",
-                              pnode->GetId());
+                    LogPrint(BCLog::NET, "version handshake timeout from %d\n",
+                             pnode->GetId());
                     pnode->fDisconnect = true;
                 }
             }
@@ -1544,11 +1541,11 @@
 #ifdef USE_UPNP
 static CThreadInterrupt g_upnp_interrupt;
 static std::thread g_upnp_thread;
-void ThreadMapPort() {
+static void ThreadMapPort() {
     std::string port = strprintf("%u", GetListenPort());
-    const char *multicastif = 0;
-    const char *minissdpdpath = 0;
-    struct UPNPDev *devlist = 0;
+    const char *multicastif = nullptr;
+    const char *minissdpdpath = nullptr;
+    struct UPNPDev *devlist = nullptr;
     char lanaddr[64];
 
 #ifndef UPNPDISCOVER_SUCCESS
@@ -1612,9 +1609,7 @@
             } else {
                 LogPrintf("UPnP Port Mapping successful.\n");
             }
-        }
-
-        while (g_upnp_interrupt.sleep_for(std::chrono::minutes(20)));
+        } while (g_upnp_interrupt.sleep_for(std::chrono::minutes(20)));
 
         r = UPNP_DeletePortMapping(urls.controlURL, data.first.servicetype,
                                    port.c_str(), "TCP", 0);
@@ -1625,7 +1620,7 @@
     } else {
         LogPrintf("No valid UPnP IGDs found\n");
         freeUPNPDevlist(devlist);
-        devlist = 0;
+        devlist = nullptr;
         if (r != 0) {
             FreeUPNPUrls(&urls);
         }
@@ -1693,7 +1688,7 @@
 
         LOCK(cs_vNodes);
         int nRelevant = 0;
-        for (auto pnode : vNodes) {
+        for (const CNode *pnode : vNodes) {
             nRelevant += pnode->fSuccessfullyConnected && !pnode->fFeeler &&
                          !pnode->fOneShot && !pnode->m_manual_connection &&
                          !pnode->fInbound;
@@ -1797,7 +1792,7 @@
     int nOutbound = 0;
     {
         LOCK(cs_vNodes);
-        for (CNode *pnode : vNodes) {
+        for (const CNode *pnode : vNodes) {
             if (!pnode->fInbound && !pnode->m_manual_connection &&
                 !pnode->fFeeler && !pnode->fDisconnect && !pnode->fOneShot &&
                 pnode->fSuccessfullyConnected) {
@@ -1874,7 +1869,7 @@
         std::set<std::vector<uint8_t>> setConnected;
         {
             LOCK(cs_vNodes);
-            for (CNode *pnode : vNodes) {
+            for (const CNode *pnode : vNodes) {
                 if (!pnode->fInbound && !pnode->m_manual_connection) {
                     // Netgroups for inbound and addnode peers are not excluded
                     // because our goal here is to not use multiple of our
@@ -2454,7 +2449,7 @@
     }
 
     if (clientInterface) {
-        clientInterface->InitMessage(_("Loading addresses..."));
+        clientInterface->InitMessage(_("Loading P2P addresses..."));
     }
     // Load addresses from peers.dat
     int64_t nStart = GetTimeMillis();
@@ -2701,9 +2696,8 @@
 
 bool CConnman::AddNode(const std::string &strNode) {
     LOCK(cs_vAddedNodes);
-    for (std::vector<std::string>::const_iterator it = vAddedNodes.begin();
-         it != vAddedNodes.end(); ++it) {
-        if (strNode == *it) {
+    for (const std::string &it : vAddedNodes) {
+        if (strNode == it) {
             return false;
         }
     }
@@ -2732,9 +2726,8 @@
     }
 
     int nNum = 0;
-    for (std::vector<CNode *>::const_iterator it = vNodes.begin();
-         it != vNodes.end(); ++it) {
-        if (flags & ((*it)->fInbound ? CONNECTIONS_IN : CONNECTIONS_OUT)) {
+    for (const auto &pnode : vNodes) {
+        if (flags & (pnode->fInbound ? CONNECTIONS_IN : CONNECTIONS_OUT)) {
             nNum++;
         }
     }