Hello,
I had an application running on SCTP port 3890 for a few days and I
stopped it (kill <pid>) for maintenance purposes. After that I’m not
able to bind on port.
The same situation happened in the past and the only way that I found
to fix it was to restart the server. I was hoping that you can help me
fixing this issue without restart.
The application is not running and the port is not used by anything else:
[root@server1 /]# netstat -lanp | grep 3890
[root@server1 /]#
I tried to use the sctp_test in order to exclude any issue on the
application and it also cannot bind on that port (my IP address is
replaced with <IPv4>):
[root@server1 /]# /usr/bin/sctp_test -H <IPv4> -P 3890 -l
local:addr=<IPv4>, port=ndsconnect, family=2
seed = 1574684002
Starting tests...
socket(SOCK_SEQPACKET, IPPROTO_SCTP) -> sk=3
bind(sk=3, [a:<IPv4>,p:ndsconnect]) -- attempt 1/10
bind(sk=3, [a:<IPv4>,p:ndsconnect]) -- attempt 2/10
bind(sk=3, [a:<IPv4>,p:ndsconnect]) -- attempt 3/10
bind(sk=3, [a:<IPv4>,p:ndsconnect]) -- attempt 4/10
bind(sk=3, [a:<IPv4>,p:ndsconnect]) -- attempt 5/10
bind(sk=3, [a:<IPv4>,p:ndsconnect]) -- attempt 6/10
bind(sk=3, [a:<IPv4>,p:ndsconnect]) -- attempt 7/10
bind(sk=3, [a:<IPv4>,p:ndsconnect]) -- attempt 8/10
bind(sk=3, [a:<IPv4>,p:ndsconnect]) -- attempt 9/10
bind(sk=3, [a:<IPv4>,p:ndsconnect]) -- attempt 10/10
Maximum bind() attempts. Die now...
I have no issues while binding on other ports:
[root@server1 /]# /usr/bin/sctp_test -H <IPv4> -P 3891 -l
local:addr=<IPv4>, port=rtc-pm-port, family=2
seed = 1574684925
Starting tests...
socket(SOCK_SEQPACKET, IPPROTO_SCTP) -> sk=3
bind(sk=3, [a:<IPv4>,p:rtc-pm-port]) -- attempt 1/10
listen(sk=3,backlog=100)
Server: Receiving packets.
recvmsg(sk=3) ^C
There are no active SCTP associations:
[root@server1 log]# tail /proc/net/sctp/* -n 10000
==> /proc/net/sctp/assocs <==
ASSOC SOCK STY SST ST HBKT ASSOC-ID TX_QUEUE RX_QUEUE UID INODE
LPORT RPORT LADDRS <-> RADDRS HBINT INS OUTS MAXRT T1X T2X RTXC
==> /proc/net/sctp/eps <==
ENDPT SOCK STY SST HBKT LPORT UID INODE LADDRS
==> /proc/net/sctp/remaddr <==
ADDR ASSOC_ID HB_ACT RTO MAX_PATH_RTX REM_ADDR_RTX START
==> /proc/net/sctp/snmp <==
SctpCurrEstab 0
SctpActiveEstabs 0
SctpPassiveEstabs 602
SctpAborteds 13
SctpShutdowns 589
SctpOutOfBlues 29128
SctpChecksumErrors 0
SctpOutCtrlChunks 891800
SctpOutOrderChunks 135693
SctpOutUnorderChunks 0
SctpInCtrlChunks 941831
SctpInOrderChunks 122325
SctpInUnorderChunks 13931
SctpFragUsrMsgs 0
SctpReasmUsrMsgs 0
SctpOutSCTPPacks 1027573
SctpInSCTPPacks 1035656
SctpT1InitExpireds 0
SctpT1CookieExpireds 0
SctpT2ShutdownExpireds 0
SctpT3RtxExpireds 81
SctpT4RtoExpireds 0
SctpT5ShutdownGuardExpireds 0
SctpDelaySackExpireds 57489
SctpAutocloseExpireds 0
SctpT3Retransmits 80
SctpPmtudRetransmits 0
SctpFastRetransmits 0
SctpInPktSoftirq 1035623
SctpInPktBacklog 19
SctpInPktDiscards 29139
SctpInDataChunkDiscards 27869
Other useful information:
[root@server1 log]# uname -a
Linux server1 2.6.32-754.11.1.el6.x86_64 #1 SMP Tue Feb 26 15:38:56
UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
[root@server1 log]# cat /etc/redhat-release
CentOS release 6.10 (Final)
[root@server1 log]# rpm -qa | grep sctp
lksctp-tools-1.0.10-7.el6.x86_64
I don’t find any relevant information on /var/log
I also disabled IPv6 (although I’m not using it) in an attempt to
isolate the issue but there was no difference.
Thanks in advance!
Kind regards,
Emanuel
