Cannot receive Multicast package

[PHLICS_Admin]

Hi All,

There are two network cards in one computer (named A) , and there is one
network card in another computer(named B).

On computer A: one network card is used to connect to internet, and the
other network card is used in intranet whose ipaddress is 192.168.0.1
On computer B: the network card's ipaddress is 192.168.0.2.

These two computer can connect to each other.

The question is :
B can receive multicast sent from A, A cannot receive the package from B
(A can receive multicast package from itself)
If disable the internet network card on A, A can receive multicast
package from B.

Would you please give me some advise on this issue.

Thanks ,

Phlics.

[Rich Blum]

"PHLICS_Adm in" <ph****@hotmail .com> wrote in message news:<O3******* *******@TK2MSFT NGP09.phx.gbl>. ..

Hi All,

There are two network cards in one computer (named A) , and there is one
network card in another computer(named B).

On computer A: one network card is used to connect to internet, and the
other network card is used in intranet whose ipaddress is 192.168.0.1
On computer B: the network card's ipaddress is 192.168.0.2.

These two computer can connect to each other.

The question is :
B can receive multicast sent from A, A cannot receive the package from B
(A can receive multicast package from itself)
If disable the internet network card on A, A can receive multicast
package from B.

Phlics -

When you have more than one network card in a computer, you should
specify which card you want to receive multicast messages on in your
socket constructor, otherwise the socket will choose one for itself
(which may or may not be a good thing).

If you are using a UdpClient object, this would look like:

IPEndPoint iep = new IPEndPoint(IPAd dress.Parse("19 2.168.0.1"),
9050);
UdpClient sock = new UdpClient(iep);
sock.JoinMultic astGroup(IPAddr ess.Parse("224. 100.0.1"));

If you are using a Socket object, it would look like this:

Socket sock = new Socket(AddressF amily.InterNetw ork,
SocketType.Dgra m,
ProtocolType.Ud p);
IPEndPoint iep = new IPEndPoint(IPAd dress.Parse("19 2.168.0.1"),
9050);
sock.Bind(iep);
sock.SetSocketO ption(SocketLev el.IP,
SocketOptionNam e.AddMembership ,
new
MulticastOption (IPAddress.Pars e("224.100.0.1" )));
As a side note, if you want to receive multicast packets on both
interfaces, you can use the IPAddress.Any value for the IPEndPoint
constructor. Hope this helps solve your problem.

Rich Blum - Author
"C# Network Programming" (Sybex)
http://www.sybex.com/sybexbooks.nsf/Booklist/4176
"Network Performance Open Source Toolkit" (Wiley)
http://www.wiley.com/WileyCDA/WileyT...471433012.html

[PHLICS_Admin]

Thanks , but it does not work.

Other information:
If I switch the network cards(change the card used for internet to
intranet ...), it works .

Regards,
"Rich Blum" <ri*******@juno .com> wrote in message
news:cc******** *************** **@posting.goog le.com...

"PHLICS_Adm in" <ph****@hotmail .com> wrote in message

news:<O3******* *******@TK2MSFT NGP09.phx.gbl>. ..

Hi All,

There are two network cards in one computer (named A) , and there is one
network card in another computer(named B).

On computer A: one network card is used to connect to internet, and the
other network card is used in intranet whose ipaddress is 192.168.0.1
On computer B: the network card's ipaddress is 192.168.0.2.

These two computer can connect to each other.

The question is :
B can receive multicast sent from A, A cannot receive the package from B (A can receive multicast package from itself)
If disable the internet network card on A, A can receive multicast
package from B.

Phlics -

When you have more than one network card in a computer, you should
specify which card you want to receive multicast messages on in your
socket constructor, otherwise the socket will choose one for itself
(which may or may not be a good thing).

If you are using a UdpClient object, this would look like:

IPEndPoint iep = new IPEndPoint(IPAd dress.Parse("19 2.168.0.1"),
9050);
UdpClient sock = new UdpClient(iep);
sock.JoinMultic astGroup(IPAddr ess.Parse("224. 100.0.1"));

If you are using a Socket object, it would look like this:

Socket sock = new Socket(AddressF amily.InterNetw ork,
SocketType.Dgra m,
ProtocolType.Ud p);
IPEndPoint iep = new IPEndPoint(IPAd dress.Parse("19 2.168.0.1"),
9050);
sock.Bind(iep);
sock.SetSocketO ption(SocketLev el.IP,
SocketOptionNam e.AddMembership ,
new
MulticastOption (IPAddress.Pars e("224.100.0.1" )));
As a side note, if you want to receive multicast packets on both
interfaces, you can use the IPAddress.Any value for the IPEndPoint
constructor. Hope this helps solve your problem.

Rich Blum - Author
"C# Network Programming" (Sybex)
http://www.sybex.com/sybexbooks.nsf/Booklist/4176
"Network Performance Open Source Toolkit" (Wiley)
http://www.wiley.com/WileyCDA/WileyT...471433012.html

[PHLICS_Admin]

Following code snip is used :

this._clsMCastR eceiver = new Socket(AddressF amily.InterNetw ork,
SocketType.Dgra m, ProtocolType.Ud p);
IPEndPoint ipep=new IPEndPoint(IPAd dress.Any , CIMSys.MCastPor t);
this._clsMCastR eceiver.Bind(ip ep);
IPAddress ip=IPAddress.Pa rse(CIMSys.MCas tIPAddress);

this._clsMCastR eceiver.SetSock etOption(Socket OptionLevel.IP,
SocketOptionNam e.AddMembership , new MulticastOption (ip , IPAddress.Any)) ;

When I disable the internet network card , it works correctly.

Please give me advise on it .

Thanks,

Phlics.

"Rich Blum" <ri*******@juno .com> wrote in message
news:cc******** *************** **@posting.goog le.com...

"PHLICS_Adm in" <ph****@hotmail .com> wrote in message

news:<O3******* *******@TK2MSFT NGP09.phx.gbl>. ..

Hi All,

There are two network cards in one computer (named A) , and there is one
network card in another computer(named B).

On computer A: one network card is used to connect to internet, and the
other network card is used in intranet whose ipaddress is 192.168.0.1
On computer B: the network card's ipaddress is 192.168.0.2.

These two computer can connect to each other.

The question is :
B can receive multicast sent from A, A cannot receive the package from B (A can receive multicast package from itself)
If disable the internet network card on A, A can receive multicast
package from B.

Phlics -

When you have more than one network card in a computer, you should
specify which card you want to receive multicast messages on in your
socket constructor, otherwise the socket will choose one for itself
(which may or may not be a good thing).

If you are using a UdpClient object, this would look like:

IPEndPoint iep = new IPEndPoint(IPAd dress.Parse("19 2.168.0.1"),
9050);
UdpClient sock = new UdpClient(iep);
sock.JoinMultic astGroup(IPAddr ess.Parse("224. 100.0.1"));

If you are using a Socket object, it would look like this:

Socket sock = new Socket(AddressF amily.InterNetw ork,
SocketType.Dgra m,
ProtocolType.Ud p);
IPEndPoint iep = new IPEndPoint(IPAd dress.Parse("19 2.168.0.1"),
9050);
sock.Bind(iep);
sock.SetSocketO ption(SocketLev el.IP,
SocketOptionNam e.AddMembership ,
new
MulticastOption (IPAddress.Pars e("224.100.0.1" )));
As a side note, if you want to receive multicast packets on both
interfaces, you can use the IPAddress.Any value for the IPEndPoint
constructor. Hope this helps solve your problem.

Rich Blum - Author
"C# Network Programming" (Sybex)
http://www.sybex.com/sybexbooks.nsf/Booklist/4176
"Network Performance Open Source Toolkit" (Wiley)
http://www.wiley.com/WileyCDA/WileyT...471433012.html

[Rich Blum]

"PHLICS_Adm in" <ph****@hotmail .com> wrote in message news:<OD******* *******@TK2MSFT NGP12.phx.gbl>. ..

this._clsMCastR eceiver.SetSock etOption(Socket OptionLevel.IP,
SocketOptionNam e.AddMembership , new MulticastOption (ip , IPAddress.Any)) ;

When I disable the internet network card , it works correctly.

Phlics -

Have you tried using the MulticastOption constructor that only
uses the multicast IP address, and not the local IP address?
Alternatively, have you tried specifying just the proper network card
IP address as the local address?

Rich Blum - Author
"C# Network Programming" (Sybex)
http://www.sybex.com/sybexbooks.nsf/Booklist/4176
"Network Performance Open Source Toolkit" (Wiley)
http://www.wiley.com/WileyCDA/WileyT...471433012.html

[PHLICS_Admin]

I have tried , but it does not work .

There are two network card on the computer. If disable the network card
(which connect to internet) , it works .

Thanks,

"Rich Blum" <ri*******@juno .com> wrote in message
news:cc******** *************** ***@posting.goo gle.com...

"PHLICS_Adm in" <ph****@hotmail .com> wrote in message

news:<OD******* *******@TK2MSFT NGP12.phx.gbl>. ..

this._clsMCastR eceiver.SetSock etOption(Socket OptionLevel.IP,
SocketOptionNam e.AddMembership , new MulticastOption (ip , IPAddress.Any)) ;
When I disable the internet network card , it works correctly.

Phlics -

Have you tried using the MulticastOption constructor that only
uses the multicast IP address, and not the local IP address?
Alternatively, have you tried specifying just the proper network card
IP address as the local address?

Rich Blum - Author
"C# Network Programming" (Sybex)
http://www.sybex.com/sybexbooks.nsf/Booklist/4176
"Network Performance Open Source Toolkit" (Wiley)
http://www.wiley.com/WileyCDA/WileyT...471433012.html

[PHLICS_Admin]

Following code snip is used :

this._clsMCastR eceiver = new Socket(AddressF amily.InterNetw ork,
SocketType.Dgra m, ProtocolType.Ud p);
IPEndPoint ipep=new IPEndPoint(IPAd dress.Any , CIMSys.MCastPor t);
this._clsMCastR eceiver.Bind(ip ep);
IPAddress ip=IPAddress.Pa rse(CIMSys.MCas tIPAddress);

this._clsMCastR eceiver.SetSock etOption(Socket OptionLevel.IP,
SocketOptionNam e.AddMembership , new MulticastOption (ip , IPAddress.Any)) ;

When I disable the internet network card , it works correctly.

Please give me advise on it .

Thanks,

Phlics.

"PHLICS_Adm in" <ph****@hotmail .com> wrote in message
news:O3******** ******@TK2MSFTN GP09.phx.gbl...

Hi All,

There are two network cards in one computer (named A) , and there is one
network card in another computer(named B).

On computer A: one network card is used to connect to internet, and the
other network card is used in intranet whose ipaddress is 192.168.0.1
On computer B: the network card's ipaddress is 192.168.0.2.

These two computer can connect to each other.

The question is :
B can receive multicast sent from A, A cannot receive the package from B (A can receive multicast package from itself)
If disable the internet network card on A, A can receive multicast
package from B.

Would you please give me some advise on this issue.

Thanks ,

Phlics.