Subject: SCTP Questions

From: "Rajib Sarkar" <[email-masked]>
Date: Thu, 15 May 2003 11:38:32 -0700

Hi,
	I have a basic question about association establishment.
	Lets say I have and endpoint with three ip addresses, ip1, ip2 and ip3.
When the user of SCTP tries to establish an association using the endpoint,
it specifies three source addresses ip2, ip3 and ip4, will the association
be rejected by SCTP because the endpoint does not contain ip address ip4?
Regards
Rajib

---

From: "Randall Stewart (cisco)" <[email-masked]>
Date: Thu, 15 May 2003 16:32:06 -0500

>be rejected by SCTP because the endpoint does not contain ip address ip4?
I don't think I follow your example...

I the user do

fd = socket(AF_INET,SOCKET_DGRAM,IPPROTO_SCTP);

sockaddr.sin_addr.s_addr = ip1;
soackaddr.sin_port = port;

bind(fd,&sockaddr);

to get ip1 bound .. .then

sockaddr.sin_addr.s_addr = ip2;

sctp_bindx(fd,&sockaddr);

sockaddr.sin_addr.s_addr = ip3;

sctp_bindx(fd, &sockaddr);

Now, is your qustion to the local app doing;

send_msg(fd....);

Or to a peer doing

send_msg(some-fd,... msg-toip4)?

The local endpoint specifies the addresses by binding.. it has no
way to specify ip4 at all.

The peer endpoint (not the binder) will send to ONE address... if it 
picks IP4 in the
beginning.. it will get an ABORT b ack.

If it picks ip3 and sends.. fine the data goes across/assoc is established..

Then if trys agaion to send to

ip4 on that fd... it will again get an ABORT back.. (not aborting its
assocaition... since the UDP style will consider it a NEW assocaition
setting up .. aka the otehr endpoint does not have IP4)...

Does that answer your question?

R

-- 
Randall R. Stewart
ITD
Cisco Systems Inc.
[email-masked] 815-342-5222(cell) or 815-477-2127(office)