check availability of particular address

libi2pd/RouterInfo.cpp

@@ -837,6 +837,11 @@ namespace data
 			return m_SupportedTransports & (eNTCP2V4 | eNTCP2V6);
 	}
 
+	bool RouterInfo::IsNTCP2V6 () const
+	{
+		return m_SupportedTransports & eNTCP2V6;
+	}	
+		
 	bool RouterInfo::IsV6 () const
 	{
 		return m_SupportedTransports & (eSSUV6 | eNTCP2V6);

libi2pd/RouterInfo.h

@@ -170,6 +170,7 @@ namespace data
 			bool IsSSU (bool v4only = true) const;
 			bool IsSSUV6 () const;
 			bool IsNTCP2 (bool v4only = true) const;
+			bool IsNTCP2V6 () const;	
 			bool IsV6 () const;
 			bool IsV4 () const;
 			bool IsMesh () const;	
@@ -179,7 +180,7 @@ namespace data
 			void DisableV4 ();
 			void EnableMesh ();
 			void DisableMesh ();	
-			bool IsCompatible (const RouterInfo& other) const { return m_SupportedTransports & other.m_SupportedTransports; };
+			bool IsCompatible (const RouterInfo& other) const { return m_SupportedTransports & other.m_SupportedTransports; };		
 			bool HasValidAddresses () const { return m_SupportedTransports; };
 			bool UsesIntroducer () const;
 			bool IsIntroducer () const { return m_Caps & eSSUIntroducer; };

libi2pd/Transports.cpp

@@ -397,7 +397,7 @@ namespace transport
 					std::shared_ptr<const RouterInfo::Address> address;
 					if (!peer.numAttempts) // NTCP2 ipv6
 					{
-						if (context.SupportsV6 ())
+						if (context.GetRouterInfo ().IsNTCP2V6 () && peer.router->IsNTCP2V6 ())
 						{	
 							address = peer.router->GetPublishedNTCP2V6Address ();
 							if (address && m_CheckReserved && i2p::util::net::IsInReservedRange(address->host))
@@ -407,7 +407,7 @@ namespace transport
 					}
 					if (!address && peer.numAttempts == 1) // NTCP2 ipv4	
 					{	
-						if (context.SupportsV4 () && !peer.router->IsUnreachable ())
+						if (context.GetRouterInfo ().IsNTCP2 (true) && peer.router->IsNTCP2 (true) && !peer.router->IsUnreachable ())
 						{	
 							address = peer.router->GetPublishedNTCP2V4Address ();
 							if (address && m_CheckReserved && i2p::util::net::IsInReservedRange(address->host))
@@ -453,7 +453,7 @@ namespace transport
 			if (peer.numAttempts == 3) // Mesh
 			{
 				peer.numAttempts++;
-				if (context.SupportsMesh () && m_NTCP2Server)
+				if (m_NTCP2Server && context.GetRouterInfo ().IsMesh () && peer.router->IsMesh ())
 				{
 					auto address = peer.router->GetYggdrasilAddress ();
 					if (address)