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### Description

Kamailio is unable to create a SCTP association to IP address that is reachable normally when dispatcher.list is configured as following: ``` 760320003 sip:10.59.144.2:5063;transport=sctp 9 0 dstid=1 760320003 sip:10.59.144.130:5063;transport=sctp 9 0 dstid=1 ``` 10.59.144.2 and 10.59.144.130 are IPs of same endpoint treated as primary and secondary, Kamailio can't send probe (OPTIONS requests) as SCTP association can't be created.

Issue doesn't exist on RHEL/Centos 6.

### Troubleshooting

#### Reproduction

Use previously mentioned dispatcher list with changed IP addresses to match local configuration.

SCTP part of kamailio.cfg

``` # if not OS default is used #modparam("sctp", "sctp_socket_rcvbuf", 14096) #modparam("sctp", "sctp_socket_sndbuf", 14096) # Number of milliseconds before an unsent message/chunk is dropped. modparam("sctp", "sctp_send_ttl", 10000) modparam("sctp", "sctp_autoclose", 300) # How many times to attempt re-sending a message on a re-opened association, if the sctp stack did give up sending it (it's not related to sctp protocol level retransmission). Useful to improve reliability with peers that reboot/restart or fail over to another machine. modparam("sctp", "sctp_send_retries", 1) modparam("sctp", "sctp_srto_initial", 200) modparam("sctp", "sctp_srto_max", 250) modparam("sctp", "sctp_srto_min", 150) modparam("sctp", "sctp_asocmaxrxt", 4) modparam("sctp", "sctp_init_max_attempts", 3) modparam("sctp", "sctp_init_max_timeo", 1000) modparam("sctp", "sctp_hbinterval", 1000) modparam("sctp", "sctp_pathmaxrxt", 2) modparam("sctp", "sctp_sack_delay", 10) modparam("sctp", "sctp_sack_freq", 1) modparam("sctp", "sctp_max_burst", 4) ```

#### Debugging Data

<!-- If you got a core dump, use gdb to extract troubleshooting data - full backtrace, local variables and the list of the code at the issue location.

gdb /path/to/kamailio /path/to/corefile bt full info locals list

If you are familiar with gdb, feel free to attach more of what you consider to be relevant. -->

``` (paste your debugging data here) ```

#### Log Messages

<!-- Check the syslog file and if there are relevant log messages printed by Kamailio, add them next, or attach to issue, or provide a link to download them (e.g., to a pastebin site). -->

``` Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2294]: DEBUG: dispatcher [dispatch.c:3234]: ds_ping_result_helper(): probing set, but not mode DS_PROBE_INACTIVE Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2294]: DEBUG: dispatcher [dispatch.c:3268]: ds_ping_set(): probing set #760320003, URI sip:10.59.144.2:5063;transport=sctp Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2294]: DEBUG: dispatcher [dispatch.c:3293]: ds_ping_set(): Default ping_from: sip:siplb@sdp.t-mobile.at Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2294]: DEBUG: tm [uac.c:435]: t_uac_prepare(): next_hop=sip:10.59.144.2:5063;transport=sctp Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2294]: DEBUG: <core> [core/resolve.c:1244]: srv_sip_resolvehost(): 10.59.144.2:5063 proto=4 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2281]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.130:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.130:5063: SCTP_ADDR_ADDED: assoc_id 0 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2294]: DEBUG: <core> [core/resolve.c:1356]: srv_sip_resolvehost(): returning 0xa7c280 (10.59.144.2:5063 proto=4) Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2294]: DEBUG: tm [uac.c:158]: dlg2hash(): hashid 27287 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2281]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.130:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.130:5063: SCTP_ADDR_MADE_PRIM: assoc_id 0 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2280]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.130:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.130:5063: SCTP_ADDR_MADE_PRIM: assoc_id 0 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2294]: DEBUG: tm [uac.c:652]: send_prepared_request_impl(): uac: 0x7fbf4eb4e5b8 branch: 0 to 10.59.144.2:5063 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2294]: DEBUG: tm [../../core/onsend.h:69]: run_onsend(): required parameters are not available - ignoring Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2282]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.2:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.2:5063: SCTP_ADDR_ADDED: assoc_id 0 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2278]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.2:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.2:5063: SCTP_ADDR_MADE_PRIM: assoc_id 0 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2282]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.2:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.2:5063: SCTP_ADDR_MADE_PRIM: assoc_id 0 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2285]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.2:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.2:5063: SCTP_ADDR_MADE_PRIM: assoc_id 0 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2283]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.130:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.130:5063: SCTP_ADDR_MADE_PRIM: assoc_id 0 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2279]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.130:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.130:5063: SCTP_ADDR_MADE_PRIM: assoc_id 0 Aug 6 18:19:13 sdp-lbref02 /usr/sbin/kamailio[2279]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.2:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.2:5063: SCTP_ADDR_MADE_PRIM: assoc_id 0 Aug 6 18:19:14 sdp-lbref02 /usr/sbin/kamailio[2280]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.2:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.2:5063: SCTP_ADDR_MADE_PRIM: assoc_id 0 Aug 6 18:19:14 sdp-lbref02 /usr/sbin/kamailio[2278]: DEBUG: sctp [sctp_server.c:2317]: sctp_handle_notification(): sctp notification from 10.59.144.130:5063 on sdp-lbref02-sigtran01:5060: SCTP_PEER_ADDR_CHANGE: 10.59.144.130:5063: SCTP_ADDR_MADE_PRIM: assoc_id 0 Aug 6 18:19:15 sdp-lbref02 /usr/sbin/kamailio[2285]: DEBUG: sctp [sctp_server.c:2340]: sctp_handle_notification(): sctp notification from 10.59.144.130:5063 on sdp-lbref02-sigtran01:5060: SCTP_ASSOC_CHANGE: SCTP_CANT_STR_ASSOC: assoc_id 0, ostreams 0, istreams 0 Aug 6 18:19:15 sdp-lbref02 /usr/sbin/kamailio[2282]: DEBUG: sctp [sctp_server.c:2340]: sctp_handle_notification(): sctp notification from 10.59.144.2:5063 on sdp-lbref02-sigtran01:5060: SCTP_ASSOC_CHANGE: SCTP_CANT_STR_ASSOC: assoc_id 0, ostreams 0, istreams 0 Aug 6 18:19:15 sdp-lbref02 /usr/sbin/kamailio[2285]: DEBUG: sctp [sctp_server.c:2299]: sctp_handle_notification(): sctp notification from 10.59.144.2:5063 on sdp-lbref02-sigtran01:5060: SCTP_SEND_FAILED: error 0, assoc_id 0, flags 0 Aug 6 18:19:15 sdp-lbref02 /usr/sbin/kamailio[2285]: DEBUG: sctp [sctp_server.c:2098]: sctp_handle_send_failed(): sctp: RETRY-ing (1) ```

#### SIP Traffic

<!-- If the issue is exposed by processing specific SIP messages, grab them with ngrep or save in a pcap file, then add them next, or attach to issue, or provide a link to download them (e.g., to a pastebin site). -->

``` (paste your sip traffic here) ```

### Possible Solutions

<!-- If you found a solution or workaround for the issue, describe it. Ideally, provide a pull request with a fix. -->

Issue is gone when one of IP addresses is removed from dispatcher.list.

### Additional Information

* **Kamailio Version** - output of `kamailio -v`

``` kamailio -v version: kamailio 5.3.5 (x86_64/linux) 9e70e8 flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLACKLIST, HAVE_RESOLV_RES, TLS_PTHREAD_MUTEX_SHARED ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. id: 9e70e8 compiled on 12:22:26 Jun 22 2020 with gcc 8.3.1

```

Also tested latest 5.2 and 5.4

* **Operating System**:

<!-- Details about the operating system, the type: Linux (e.g.,: Debian 8.4, Ubuntu 16.04, CentOS 7.1, ...), MacOS, xBSD, Solaris, ...; Kernel details (output of `uname -a`) -->

``` [root@sdp-lbref02 ~]# uname -a Linux sdp-lbref02 4.18.0-193.14.3.el8_2.x86_64 #1 SMP Mon Jul 20 15:02:29 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux [root@sdp-lbref02 ~]# cat /etc/redhat-release Red Hat Enterprise Linux release 8.2 (Ootpa) ```