diff --git a/libservice/src/Aggregator.cpp b/libservice/src/Aggregator.cpp
index 502c2f21..fcb767c0 100644
--- a/libservice/src/Aggregator.cpp
+++ b/libservice/src/Aggregator.cpp
@@ -31,7 +31,7 @@ static std::string getEndpoint(const std::string& host, const std::string& url)
 static bool isIpv4ClientExternal(const IpAddressChecker& ipChecker, const std::string& addr) {
 	in_addr_t clientAddrBinary;
 	if (inet_pton(AF_INET, addr.c_str(), &clientAddrBinary) != 1) {
-		throw std::runtime_error("Cannot parse IPv4 client address: {}" + addr);
+		throw std::runtime_error("Couldn't parse IPv4 client address");
 	}
 	return ipChecker.isV4AddressExternal(clientAddrBinary);
 }
@@ -39,35 +39,45 @@ static bool isIpv4ClientExternal(const IpAddressChecker& ipChecker, const std::s
 static bool isIpv6ClientExternal(const IpAddressChecker& ipChecker, const std::string& addr) {
 	in6_addr clientAddrBinary{};
 	if (inet_pton(AF_INET6, addr.c_str(), &clientAddrBinary) != 1) {
-		throw std::runtime_error("Cannot parse IPv6 client address: {}" + addr);
+		throw std::runtime_error("Couldn't parse IPv6 client address");
 	}
 	return ipChecker.isV6AddressExternal(clientAddrBinary);
 }
 
-static bool isClientExternal(const IpAddressChecker& ipChecker, const std::string& addr, bool isIpV6) {
-	return isIpV6 ? isIpv6ClientExternal(ipChecker, addr) : isIpv4ClientExternal(ipChecker, addr);
+static bool isClientExternal(const IpAddressChecker& ipChecker, const std::string& addr, bool isIpv6) {
+	return isIpv6 ? isIpv6ClientExternal(ipChecker, addr) : isIpv4ClientExternal(ipChecker, addr);
+}
+
+static bool isClientExternal(const IpAddressChecker& ipChecker, const std::string& addr) {
+	bool isPossiblyIpv6{std::count(addr.begin(), addr.end(), ':') >= 2};
+	return isClientExternal(ipChecker, addr, isPossiblyIpv6);
 }
 
 static void incrementServiceClientsNumber(
 		const IpAddressChecker& ipChecker, Service& service, const httpparser::HttpRequest& request, const DiscoverySessionMeta& meta) {
+	bool isExternal{false};
 	std::string clientAddr;
-	if (!request.xForwardedFor.empty()) {
-		clientAddr = request.xForwardedFor.front();
-	} else if (discoverySessionFlagsIsIPv4(meta.flags)) {
-		clientAddr = ipv4ToString(meta.sourceIPData);
-	} else if (discoverySessionFlagsIsIPv6(meta.flags)) {
-		clientAddr = ipv6ToString(meta.sourceIPData);
-	}
-
 	try {
-		if (isClientExternal(ipChecker, clientAddr, discoverySessionFlagsIsIPv6(meta.flags))) {
-			++service.externalClientsNumber;
+		if (!request.xForwardedFor.empty()) {
+			clientAddr = request.xForwardedFor.front();
+			isExternal = isClientExternal(ipChecker, clientAddr);
+		} else if (discoverySessionFlagsIsIPv4(meta.flags)) {
+			clientAddr = ipv4ToString(meta.sourceIPData);
+			isExternal = isClientExternal(ipChecker, clientAddr, false);
+		} else if (discoverySessionFlagsIsIPv6(meta.flags)) {
+			clientAddr = ipv6ToString(meta.sourceIPData);
+			isExternal = isClientExternal(ipChecker, clientAddr, true);
 		} else {
-			++service.internalClientsNumber;
+			return;
 		}
 	} catch (const std::runtime_error& e) {
-		LOG_TRACE(e.what());
-		return;
+		LOG_TRACE("Couldn't determine if the client is external: {} (client address: {})", e.what(), clientAddr);
+	}
+
+	if (isExternal) {
+		++service.externalClientsNumber;
+	} else {
+		++service.internalClientsNumber;
 	}
 }