关于组播端口的问题

2008-11-04 10:03:25 1.5k 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

避开海康相机组播的3个大坑：IP地址无效、端口不同步问题解决手册本文详细解析了海康工业相机组播功能部署中的三大常见问题：组播IP地址无效、端口不同步及参数同步问题。通过深入分析海康SDK的底层验证逻辑和RFC 3171标准，提供了组播地址选择、端口设置及参数同步的实用解决方案，帮助用户快速定位和修复问题，确保工业视觉系统的稳定运行。阅读详情

用udp方式向一组播地址的组播端口发送数据，先有另一主机已加入该组播域，接收该数据时候用的端口要和组播端口一样吗，应该没道理吧，不过我试的时候不一样真的是没接收不到数据，小弟第一次接触这方面，请给位达人不吝赐教！

...全文

组播——IGMP Snooping 当组播源和组成员之间为二层网络时，此时网络设备是不需要配置IGMP协议以及PIM协议的，如果此时在网络设备上配置了IGMP Snooping，则会出现以下问题（此时路由端口手动配置）只要是动态的端口，只要是端口上维持“动态”特性的协议报文（PIM或IGMP）在端口老化时间内未收到，端口就会从组播转发表中消失。该端口在2s内没有收到报告报文，则删除该成员端口，如果该成员端口收到了报告报文，重置成员端口老化时间。当端口收到IGMP报文或PIM Hello报文后，会刷新组播路由器中的路由器端口的老化时间。阅读详情

lwx_work

网络编程 18,356 成员 64,161 内容

+ 关注 + 加入社区

切换为时间正序

码农7号- 2009-09-15

打赏
举报

的确如此!
收听端口和组播的端口要一致!否则recvfrom会僵死直到天长地久!

Wenxy1 2008-11-24

打赏
举报

多播，参考一下我的blog:
http://blog.csdn.net/wenxy1/archive/2007/03/22/1537267.aspx

tingtj 2008-11-24

打赏
举报

关键就：
ip_mreq m_mrMReq; // Contains IP and interface of the host group

SOCKADDR_IN m_saHostGroup; // SOCKADDR structure to hold IP/Port of the Host group to send data to it

唉，结吧

www.wantsoft.com 隐形者源码交流

lwx_work 2008-11-24

打赏
举报

难道就要这样结贴了~

lwx_work 2008-11-24

打赏
举报

难道就要这样结贴了~

wsjdouble 2008-11-05

打赏
举报

我这儿有些代码可以共享讨论一下
#if !defined(AFX_MULTICASTSOCKET_H__269E2C7F_2037_11D3_8EF3_0000C0FD25F8__INCLUDED_)
#define AFX_MULTICASTSOCKET_H__269E2C7F_2037_11D3_8EF3_0000C0FD25F8__INCLUDED_

#if _MSC_VER >= 1000
#pragma once
#endif // _MSC_VER >= 1000
// MulticastSocket.h : header file
//

/////////////////////////////////////////////////////////////////////////////
// CMulticastSocket command target

class CMulticastSocket : public CAsyncSocket
{
// Attributes
public:

// Operations
public:
CMulticastSocket();
virtual ~CMulticastSocket();

// Overrides
public:
BOOL JoinGroup(CString, UINT, UINT, BOOL);
BOOL LeaveGroup();
BOOL SendTo(const void*, int);
void SetLoopBack(BOOL);
BOOL SetTTL(UINT nTTL);
BOOL CreateSendingSocket(UINT, BOOL);
BOOL CreateReceivingSocket(LPCTSTR, UINT);
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CMulticastSocket)
public:
virtual void OnReceive(int nErrorCode);
//}}AFX_VIRTUAL

// Generated message map functions
//{{AFX_MSG(CMulticastSocket)
// NOTE - the ClassWizard will add and remove member functions here.
//}}AFX_MSG

// Implementation
public:
char m_strBuffer[32000]; // Receiving buffer for the packet that has arrived
SOCKADDR_IN m_saHostGroup; // SOCKADDR structure to hold IP/Port of the Host group to send data to it
ip_mreq m_mrMReq; // Contains IP and interface of the host group
UINT m_nSendersPort; // Holds Port No. of the socket from which last packet was received
CString m_strSendersIP; // Hold IP of the socket from which the last packet was received
UINT m_nLocalPort; // Ephemeral port number of the sending port
CString m_strLocalIP; // IP Address of the local host or your machine
BOOL bForceNoLoopback; // If interface does not support lopback and the service is required, the bool is set to true
CAsyncSocket m_SendSocket; // Socket for sending data to the host group
};

/////////////////////////////////////////////////////////////////////////////

//{{AFX_INSERT_LOCATION}}
// Microsoft Developer Studio will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_MULTICASTSOCKET_H__269E2C7F_2037_11D3_8EF3_0000C0FD25F8__INCLUDED_)
// MulticastSocket.cpp : implementation file
//

#include "stdafx.h"
#include "MulticastSocket.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CMulticastSocket

CMulticastSocket::CMulticastSocket()
{
bForceNoLoopback = FALSE;
}

CMulticastSocket::~CMulticastSocket()
{
}

// Do not edit the following lines, which are needed by ClassWizard.
#if 0
BEGIN_MESSAGE_MAP(CMulticastSocket, CAsyncSocket)
//{{AFX_MSG_MAP(CMulticastSocket)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
#endif // 0

/////////////////////////////////////////////////////////////////////////////
// CMulticastSocket member functions

BOOL CMulticastSocket::CreateReceivingSocket(LPCTSTR strGroupIP, UINT nGroupPort)
{
/* Create socket for receiving packets from multicast group */
if(!Create(nGroupPort, SOCK_DGRAM, FD_READ))
return FALSE;

BOOL bMultipleApps = TRUE; /* allow reuse of local port if needed */
SetSockOpt(SO_REUSEADDR, (void*)&bMultipleApps, sizeof(BOOL), SOL_SOCKET);

/* Fill m_saHostGroup_in for sending datagrams */
memset(&m_saHostGroup, 0, sizeof(m_saHostGroup));
m_saHostGroup.sin_family = AF_INET;
m_saHostGroup.sin_addr.s_addr = inet_addr(strGroupIP);
m_saHostGroup.sin_port = htons((USHORT)nGroupPort);

/* Join the multicast group */
m_mrMReq.imr_multiaddr.s_addr = inet_addr(strGroupIP); /* group addr */
m_mrMReq.imr_interface.s_addr = htons(INADDR_ANY); /* use default */
if(setsockopt(m_hSocket, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char FAR *)&m_mrMReq, sizeof(m_mrMReq)) < 0)
return FALSE;

return TRUE;
}

BOOL CMulticastSocket::CreateSendingSocket(UINT nTTL, BOOL bLoopBack)
{
if(!m_SendSocket.Create(0, SOCK_DGRAM, 0)) // Create an unconnected UDP socket
return FALSE;

if(!SetTTL(nTTL)) // Set Time to Live as specified by user
AfxMessageBox("Warning! Error Setting TTL");

SetLoopBack(bLoopBack); // Enable/Disable Loopback

return TRUE;
}

BOOL CMulticastSocket::SetTTL(UINT nTTL)
{
/* Set Time to Live to parameter TTL */
if(m_SendSocket.SetSockOpt(IP_MULTICAST_TTL, &nTTL, sizeof(int), IPPROTO_IP) == 0)
return FALSE; /* Error Setting TTL */
else
return TRUE; /* else TTL set successfully */
}

void CMulticastSocket::SetLoopBack(BOOL bLoop)
{
/* Set LOOPBACK option to TRUE OR FALSE according to IsLoop parameter */
int nLoopBack = (int)bLoop;
if(m_SendSocket.SetSockOpt(IP_MULTICAST_LOOP, &nLoopBack, sizeof(int), IPPROTO_IP) == 0)
{
if(!bLoop) /* if required to stop loopback */
{
bForceNoLoopback = TRUE; /* Internally making a note that loopback has to be disabled forcefilly */

// Get IP/Port for send socket in order to disable loopback forcefully */
char localHost[255];
gethostname(localHost, 255);
struct hostent *host = gethostbyname(localHost); /* Get local host IP */
m_strLocalIP = inet_ntoa (*(struct in_addr*)*host->h_addr_list);
CString Dummy; // Dummy string to be passed to the GetSockName function
m_SendSocket.GetSockName(Dummy, m_nLocalPort); /* Get Port Number for Sending Port */
}
}
}

void CMulticastSocket::OnReceive(int nErrorCode)
{
int nError = ReceiveFrom (m_strBuffer, 32000, m_strSendersIP, m_nSendersPort);
if(nError == SOCKET_ERROR)
AfxMessageBox("Error receiving data from the host group");
else
{
if (!bForceNoLoopback || (bForceNoLoopback && !(m_strSendersIP == m_strLocalIP && m_nSendersPort == m_nLocalPort)))
{
// 1. If loopbackback is not to be forced then interface handles the loopback itself
// 2. If you have to loopback and SOCKOPT LOOPBACK fails, no problem, interfaces loopback by default
// 3. If you have to stop loopback and SOCKOPT LOOPBACK fails, ignore messages coming from your own sending socket

// TODO : Add your code for here. The packet received is in m_strBuffer
}
}

CAsyncSocket::OnReceive(nErrorCode);
}

BOOL CMulticastSocket::LeaveGroup()
{
if(setsockopt (m_hSocket, IPPROTO_IP, IP_DROP_MEMBERSHIP, (char FAR *)&m_mrMReq, sizeof(m_mrMReq)) < 0)
return FALSE;

m_SendSocket.Close(); // Close sending socket
Close(); // Close receving socket
return TRUE;
}

BOOL CMulticastSocket::SendTo(const void* strMessage, int nSize)
{
if(m_SendSocket.SendTo(strMessage, nSize, (SOCKADDR*)&m_saHostGroup, sizeof(SOCKADDR), 0) == SOCKET_ERROR)
return FALSE;
else
return TRUE;
}

BOOL CMulticastSocket::JoinGroup(CString GroupIP, UINT nGroupPort, UINT nTTL, BOOL bLoopback)
{
if(!CreateReceivingSocket(GroupIP, nGroupPort)) /* Create Socket for receiving and join the host group */
return FALSE;
if(!CreateSendingSocket(nTTL, bLoopback)) /* Create Socket for sending */
return FALSE;

return TRUE;
}

关于组播端口的问题

相关推荐