So, can I get confirmation that whether we can enhance to support the scenarios or any resolution on providing the correct routing? On Tue, Nov 26, 2013 at 9:03 AM, Sun Paul <paulrbk@xxxxxxxxx> wrote: > Hi > > we have a problem on using LKSCTP to form a 4 ways multi-homing network. > > Configuration > - Node-A has 2 IP addresses in different subnets, known as IP-A (eth1), > IP-B (eth2) > - Node-B has 2 IP addresses in different subnets, known as IP-X (eth1), > IP-Y (eth2) > > the four way paths are shown below. > 1. IP-A (11.1.1.1) to IP-X (11.1.1.11) > 2. IP-B (12.1.1.1) to IP-Y (12.1.1.11) > 3. IP-A (11.1.1.1) to IP-Y (12.1.1.11) > 4. IP-B (12.1.1.1) to IP-X (11.1.1.11) > > the HB/HB_ACK is normal for the paths " IP-A to IP-X" and "IP-B to > IP-Y", but it is not correct for the rest of two. > > First of all, we are using iproute2 to form 2 table such that when > IP-B arrives on IP-X, it will know how to route back to IP-B on the > same interface, i.e (eth1). Same logic for the path "IP-A to IP-X". > > What we observed here is that when 12.1.1.1 sends INIT to 11.1.1.11, > LKSCTP will send back the INIT_ACK to 12.1.1.1 using 12.1.1.11 but not > using the IP 11.1.1.11. > > The above operation makes the subsequence HB/HB_ACK in using wrong IP address. > > TCP trace on eth1 > 18:02:41.058640 IP 12.1.1.1.2905 > 11.1.1.11.2905: sctp (1) [INIT] > [init tag: 19933036] [rwnd: 102400] [OS: 16] [MIS: 16] [init TSN: 0] > 18:02:41.061634 IP 12.1.1.1.2905 > 11.1.1.11.2905: sctp (1) [COOKIE ECHO] > 18:02:41.062642 IP 12.1.1.1.2905 > 11.1.1.11.2905: sctp (1) [HB REQ] > 18:02:41.062846 IP 11.1.1.11.2905 > 11.1.1.1.2905: sctp (1) [HB ACK] > 18:02:41.361811 IP 11.1.1.11.2905 > 11.1.1.1.2905: sctp (1) [HB ACK] > 18:02:41.661791 IP 11.1.1.11.2905 > 11.1.1.1.2905: sctp (1) [HB ACK] > 18:02:41.961791 IP 11.1.1.11.2905 > 11.1.1.1.2905: sctp (1) [HB ACK] > > TCP trace on eth2 > 18:02:41.058755 IP 12.1.1.11.2905 > 12.1.1.1.2905: sctp (1) [INIT ACK] > [init tag: 424726157] [rwnd: 131072] [OS: 5] [MIS: 5] [init TSN: > 3340756356] > 18:02:41.061696 IP 12.1.1.11.2905 > 12.1.1.1.2905: sctp (1) [COOKIE ACK] > 18:02:41.062663 IP 12.1.1.11.2905 > 12.1.1.1.2905: sctp (1) [HB ACK] > 18:02:41.062791 IP 11.1.1.1.2905 > 12.1.1.11.2905: sctp (1) [HB REQ] > 18:02:41.361777 IP 11.1.1.1.2905 > 12.1.1.11.2905: sctp (1) [HB REQ] > 18:02:41.661772 IP 11.1.1.1.2905 > 12.1.1.11.2905: sctp (1) [HB REQ] > 18:02:41.961772 IP 11.1.1.1.2905 > 12.1.1.11.2905: sctp (1) [HB REQ] > 18:02:42.161771 IP 11.1.1.1.2905 > 12.1.1.11.2905: sctp (1) [HB REQ] > 18:02:42.461770 IP 11.1.1.1.2905 > 12.1.1.11.2905: sctp (1) [HB REQ] > 18:02:42.675770 IP 11.1.1.1.2905 > 12.1.1.11.2905: sctp (1) [HB REQ] > > > If we are using single homing, there is no problem on the SCTP > communication. Below is the TCP trace on eth1 using sctp_test > > 18:09:55.356727 IP 12.1.1.1.2905 > 11.1.1.11.2905: sctp (1) [INIT] > [init tag: 32516609] [rwnd: 102400] [OS: 16] [MIS: 16] [init TSN: 0] > 18:09:55.356811 IP 11.1.1.11.2905 > 12.1.1.1.2905: sctp (1) [INIT ACK] > [init tag: 3168861995] [rwnd: 131072] [OS: 10] [MIS: 16] [init TSN: > 1877695021] > 18:09:55.357727 IP 12.1.1.1.2905 > 11.1.1.11.2905: sctp (1) [COOKIE ECHO] > 18:09:55.357788 IP 11.1.1.11.2905 > 12.1.1.1.2905: sctp (1) [COOKIE ACK] > 18:09:55.358724 IP 12.1.1.1.2905 > 11.1.1.11.2905: sctp (1) [HB REQ] > 18:09:55.358740 IP 11.1.1.11.2905 > 12.1.1.1.2905: sctp (1) [HB ACK] > 18:09:55.379715 IP 12.1.1.1.2905 > 11.1.1.11.2905: sctp (1) [DATA] > (B)(E) [TSN: 0] [SID: 0] [SSEQ 0] [PPID 0x3] > 18:09:55.379735 IP 11.1.1.11.2905 > 12.1.1.1.2905: sctp (1) [SACK] > [cum ack 0] [a_rwnd 131064] [#gap acks 0] [#dup tsns 0] > 18:09:55.657716 IP 12.1.1.1.2905 > 11.1.1.11.2905: sctp (1) [HB REQ] > 18:09:55.657732 IP 11.1.1.11.2905 > 12.1.1.1.2905: sctp (1) [HB ACK] > > From the observations, it seems that the LKSCTP library is not able to > use the original local address when multi-homing is being used. Is > there anyway can be resolved it? > > Thanks > > PS -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
