Bind Error Address Already In Use So Reuseaddr
Contents |
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings error binding socket address already in use and policies of this site About Us Learn more about Stack
So_reuseaddr Example In C
Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs address already in use python socket Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; address already in use linux it only takes a minute: Sign up “bind: address already in use” even with SO_REUSEADDR set up vote 3 down vote favorite 2 I've written a simple echo server, which includes the following line: int yes = 1; if (setsockopt(socketfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1) { perror("setsockopt"); exit(1); } However despite this, I'm still getting an error when I
Bind Failed Address Already In Use Iperf
try to call bind on a socket I've recently used. In fact, I'm getting this error if I try to call bind on a socket I've used in this program, period, even if it's not recent - like they're not being cleared by the kernel or something. Is there something else I have to do? Here's the full code: #include
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more bind address already in use ssh about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users socat address already in use Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping
So_reuseaddr Linux
each other. Join them; it only takes a minute: Sign up Python: Binding Socket: “Address already in use” up vote 36 down vote favorite 10 I have a question regarding client socket on TCP/IP network. Let's say I http://stackoverflow.com/questions/16378470/bind-address-already-in-use-even-with-so-reuseaddr-set use try: comSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) comSocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) except socket.error, msg: sys.stderr.write("[ERROR] %s\n" % msg[1]) sys.exit(1) try: comSocket.bind(('', 5555)) comSocket.connect() except socket.error, msg: sys.stderr.write("[ERROR] %s\n" % msg[1]) sys.exit(2) The socket created will be bound to port 5555. The problem is that after ending the connection comSocket.shutdown(1) comSocket.close() Using wireshark, I see the socket closed with FIN,ACK and ACK from both sides, I can't use the port again. I get the following error: [ERROR] Address already in http://stackoverflow.com/questions/6380057/python-binding-socket-address-already-in-use use I wonder how can I clear the port right away so that next time I still can use that same port. comSocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) setsockopt doesn't seem to be able to resolve the problem Thank you! python sockets tcp port share|improve this question edited Dec 31 '13 at 19:49 asked Jun 17 '11 at 0:12 Tu Hoang 95372235 Why does a client need a specific port? –AJ. Jun 17 '11 at 0:17 Because I have to put that into a production server, and in that server, all outgoing connections are blocked. I need to specify a specific port to the socket so that they can set up a rule on the firewalls that allows the connection to go through. –Tu Hoang Jun 17 '11 at 0:46 I suggest you copy & paste the actual code. What you wrote above has an obvious error that would prevent you from seeing the behavior you claim to have seen. This leaves readers with no idea what else you have neglected to tell us that might be causing your problem. –ʇsәɹoɈ Jun 17 '11 at 1:01 2 Your network administrators should understand that outbound traffic can be controlled by destination port. –AJ. Jun 17 '11 at 1:02 4 this has enough information. there's a 99% chance the problem is caused by the
then try to restart is again, I get bind: address already in use error. This is getting really frustrating. I have no idea how to fix it. One way I tried is 1
2
3
4
5
6
7
8
9
10
11
12
http://www.cplusplus.com/forum/unices/17001/ int optval = 1 ; 58 if (setsockopt(serverSockFd,SOL_SOCKET,SO_REUSEADDR,&optval,si zeof(int)) == -1) { perror("setsockopt") ; https://forum.golangbridge.org/t/bind-address-already-in-use-even-after-listener-closed/1510 exit(-1) ; } bind(...); // bind code continued It still does not work. I am not sure if I am placing setsockopt at wrong place. Any guidance on solving this error would be very helpful. Thanks Dec 3, 2009 at 11:16am UTC kbw (7986) You need to call setsockopt(s, SOL_SOCKET, SO_REUSEADDR, ... immediately after creating the socket with int address already s = socket(AF_INET, ... It seems you're already doing that, so I'm not sure what's wrong. Dec 3, 2009 at 1:46pm UTC jsmith (5804) If you've run your program without the setsockopt() call and have not rebooted or waited long enough, the address will still be in use from that run. Otherwise I am 100% sure your setsockopt call is at the right place and is correct. Dec 3, 2009 at 2:17pm UTC kbw address already in (7986) SO_REUSEADDR is supposed to allow the waiting socket to be reused, so you don't have to wait for it to be released. The danger is, of course, that's you can receive pending data from the previous session. It's not clear what's been done between calling socket and setsockopt. If there's nothing between them, then I'm stumped too. Dec 3, 2009 at 3:10pm UTC kevinchkin (450) Thanks for the reply guys. I even tried it putting just after socket() call. It still gives that same annoying error. I have no idea what's going on. T_T Edit: jsmith: Am I supposed to wait even with setsockopt()? Actually, like kbw said, I thought that after using setsockopt() we do not have to wait. I works even without setsockopt(), if I wait. But that's the whole point that I do not want to wait. :-( Please let me know any other approach that I can take to avoid this. Thanks Last edited on Dec 3, 2009 at 3:14pm UTC Dec 3, 2009 at 7:12pm UTC jsmith (5804) No. Let me clarify. Using the SO_REUSEADDR option tells the kernel that when the socket is closed, the port bound to the socket should be freed immediately rather than kept in-use for some period of time. It does not provide a means by which the
// ln is listening on :8080 err = ln.Close() // succeeds, no error if err != nil { log.Fatal(err) } ln2, err := net.Listen("tcp", ":8080") if err != nil { log.Fatal(err) // bind: address already in use } I was wondering if SO_REUSEADDR had something to do with this, but as far as I know, that is already being used under the hood in the Go standard library when creating a new tcp listener. Any ideas how I can re-bind to that address without delay? jdh (Joe Henke) 2015-11-14 18:40:19 UTC #2 Hey Matt, I tried to reproduce this and did not on my mac but did on the go playground. Where did this happen for you? Interestingly, both on my mac and on the go playground, if you use -addr="" or change to defaultAddr to "" in the source (which I think just means it will bind to any open port, yeah?) it will never rebind to the same port, and in fact will bind to the previous attempt's port + 1. Not sure if this is significant; I don't know precisely what binding to "" is specced to do. Joe matt (Matt Holt) 2015-11-14 19:09:42 UTC #3 Thanks for trying to reproduce it - next time I'll try to provide a full code sample I'm experiencing the Go playground's behavior on my Mac. But when I ran your test program on my Mac, it passed. I will look into this further in my own program. Meanwhile, I am intensely curious as to why the test fails on the Go playground... matt (Matt Holt) 2015-11-14 19:57:23 UTC #4 Okay, I've narrowed it down a little bit. This only happens for me when my program has restarted itself using exec.Command(os.Args[0], ...) and, in that command, it sets ExtraFiles to a list of file descriptors for listeners. (Similar to this method: http://grisha.org/blog/2014/06/03/graceful-restart-in-golang/) This lets the child process (itself) use the existing listeners without downtime. In the "restarted" process, then: I close the listeners, immediately create new ones on the same addresses again, and it fails with "address already in use". But if I pause 5 seconds after closing the listener (before creating the new listener), it succeeds. The original process where the listeners were created don't have this problem. In other words, if I don't "restart" the process, I can close and create the listeners immediately, like @jdh's program does. But if I do that same thing in a restart, it doesn't work. Here's a program that reproduces what I'm describing: gist.github.com https://gist.github.com/mholt/54caa1190cc6b14a43b1 socket_reuse.go package main import ( "flag