[Lksctp-developers] Force output address

[Rafael L. <rl...@ci...>]

Hi everyone,

I am working on the AUTO_ASCONF option and I have a problem with the 
source IP address of the ASCONF packets. I am testing the case where I 
only have one interface available and I change the IP address of the 
that interface to a different one. Ideally, the association should still 
go on. The initial code tries to remove the old address but it can't, 
since it is the last address left for the association. After that, it 
adds the new address to the binding list, so in the end we have two 
local addresses to which the association is binded (the old one and the 
new one).

My problem is that the ASCONF packet is leaving with the old IP address 
as the source, even though the IP address of the interface has already 
changed. After sending the ASCONF packet, the connection hangs, 
presumably waiting for the ASCONF_ACK packet. The ASCONF_ACK packet 
returns to the old IP address (since this was the source of the ASCONF 
packet) and therefore never reaches the SCTP layer.

Is there a way to force SCTP to use the new IP address instead? Do I 
need first to tell SCTP to use the new address as primary?

Thanks,
Rafael