Openvpn: Write to Tun/tap : Invalid Argument (Code=22)

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Search this Thread 05-08-2010, 02:17 PM #1 unminser LQ Newbie Registered: May 2010 Posts: 24 Rep: OpenVpn TUN/TAP i installed the openvpn and now try to run it but: Code: [root@server openvpn]# /usr/sbin/openvpn server.conf Sat May 8 13:15:51 2010 OpenVPN 2.1.1 x86_64-redhat-linux [SSL] [LZO2] [EPOLL] [PKCS11] built on May 8 2010 Sat May 8 13:15:51 2010 NOTE: OpenVPN 2.1 requires '--script-security 2' or higher to call user-defined scripts or executables Sat May 8 13:15:51 2010 Diffie-Hellman initialized with 1024 bit key Sat May 8 13:15:51 2010 TLS-Auth MTU parms [ L:1542 D:138 EF:38 EB:0 ET:0 EL:0 ] Sat May 8 13:15:51 2010 ROUTE default_gateway=191.255.255.1 Sat May 8 13:15:51 2010 Note: Cannot open TUN/TAP dev /dev/net/tun: Permission denied (errno=13) Sat May 8 13:15:51 2010 Note: Attempting fallback to kernel 2.2 TUN/TAP interface Sat May 8 13:15:51 2010 Cannot allocate TUN/TAP dev dynamically Sat May 8 13:15:51 2010 Exiting 05-09-2010, 07:14 AM #2 catkin LQ 5k Club Registered: Dec 2008 Location: Tamil Nadu, India Distribution: Debian Posts: 8,578 Blog Entries: 31 Rep: What is the output of Code: ls -l /dev/net/tun lsmod | grep tun 05-09-2010, 10:20 AM #3 unminser LQ Newbie Registered: May 2010 Posts: 24 Original Poster Rep: Code: [root@server /]# ls -l /dev/net/tun crw------- 1 root root 10, 200 May 7 21:51 /dev/net/tun [root@dok /]# lsmod | grep tun bash: lsmod: command not found [root@server /]# 05-09-2010, 10:51 AM #4 catkin LQ 5k Club Registered: Dec 2008 Location: Tamil Nadu, India Distribution: Debian Posts: 8,578 Blog Entries: 31 Rep: Quote: Originally Posted by unminser Code: [root@server /]# ls -l /dev/net/tun crw------- 1 root root 10, 200 May 7 21:51 /dev/net/tun [root@dok /]# lsmod | grep tun bash: lsmod: command not found [root@server /]# Strange; no lsmod command? Maybe RedHat has another way to list modules loaded into the kernel. Maybe try /sbin/lsmod. I'm guessing the underlying problem is tun is not in the kernel. 05-09-2010, 11:19 AM #5 unminser LQ Newbie Registered: May 2010 Posts: 24 Original Poster Rep: Code: [root@server /]# find -name lsmod ./sbin/lsmod [root@server /]# ./sbin/lsmod | grep tun [root@server /]# [root@server /]# find -name tun ./dev/net/tun [root@server /]# im using centos 5.?.? 05-09-2010, 11:41 AM #6 catkin LQ 5k Club Registered: Dec 2008 Location: Tamil Nadu, India Distribution: Debian Posts: 8,578 Blog Entries: 31 Rep: Quote: Originally Posted by unminser Code: [root@server /]# find -name lsmod ./sbin/lsmod [root@server /]# ./sbin/lsmod | grep tun [root@server /]# [root@server /]# find -name tun ./dev/net/tun [root@server /]# im using centos 5.?.? Seems you have an unusual $PATH for root -- it usually includes /sbin. For interest echo $PATH The was no output from ./sbin/lsmod | grep tun showing the tun module was not loaded. Presuming tun is not built in to the kernel that might be enough to explain the symptoms. IDK how to load modules in RedHat but this page looks helpful. Looks like you just need to run /sbin/modprobe tun and, if it works OK (confirm with lsmod), try OpenVPN again. 05-09-2010, 11:58 AM #7 unminser LQ Newbie Registered: May 2010 Posts: 24 Original Poster Rep: Code: [root@server /]# echo $PATH /usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/bin:/bin:/usr/bin:/home/rabbit/bin [root@server /]# ./sbin/lsmod | grep tun [root@server /]# /sbin/modprobe tun FATAL: Could not load /lib/modules/2.6.18-028stab067.4/modules.dep: No such file or directory [root@server /]# ./sbin/modprobe tun FATAL: Could not load /lib/modules/2.6.18-028stab067.4/modules.dep: No such file or directory [root@server /]# 05-09-2010, 12:11 PM #8 catkin LQ 5k Club Registered: Dec 2008 Location: Tamil Nadu, India Distribution: Debian Posts: 8,578 Blog Entries: 31 Rep: Quote: Originally Posted by unminser Code: [root@server /]# echo $PATH /usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/bin:/bin:/usr/bin:/home/rabbit/bin [root@server /]# ./sbin/lsmod | grep tun [root@server /]# /sbin/modprobe tun FATAL: Could not load /lib/modules/2.6.18-028stab067.4/modules.dep: No such file or directory [root@server /]# ./sbin/modprobe tun FATAL: Could not load /lib/modules/2.6.18-028stab067.4/modules.dep: No such file or directory [root@server /]# /sbin/modprobe tun is the correct form of the command. ./sbin/modprobe tun is equivalent if the current directory is / Unless tun is built into the kernel then the problem is that it is not available as a loadable module. IDK RedHat so do not know how to resolve that. How about a new thread asking how to load tun in RedHat (and giving the RedHat release)? 05-09-2010, 12:17 PM #9 unminser LQ Newbie Registered: May 2010 Posts: 24 Original Poster Rep: Code: uname -a Linux server 2.6.18-028stab067.4 #1 SMP Thu Jan 14 17:06:11 MSK 2010 x86_64 x86_64 x86_64 GNU/Linux 05-09-2010, 12:52 PM #10 catkin LQ 5k Club Registered: Dec 2008 Location: Tamil Nadu, India Distribution: Debian Posts: 8,578 Blog Entries: 31 Rep: Quote: Originally Posted by unminser Code: uname -a Linux server 2.6.18-028stab067.4 #1 SMP Thu Jan 14 17:06:11 MSK 2010 x86_64 x86_64 x86_64 GNU/Linux That's the kernel. Do you have an /etc/*release* or /etc/*version* file that shows the version/release of RedHat? With that information we should be able to netsearch for how tun is normally set up. The fact that you have a /dev/net/tun file suggests it's in there somewhere. 05-09-2010, 12:57 PM #11 unminser LQ Newbie Registered: May 2010 Posts: 24 Original Poster Rep: im new to linux i thought uname -a give the system inofrmation Quote: CentOS release 5.4 (Final) 05-29-2011, 04:00 AM #12 mselvaprakash LQ Newbie Registered: Oct 2010 Posts: 7 Rep: Please refer the below URL: http://unixnethost.blogspot.com/2011...tallation.html Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is Off HTML code is Off Forum Rules Similar Threads Thread Thread Starter Forum Replies Last Post OpenVPN Tun/Tap error Penn Linux - Server 5 10-14-2010 03:35 PM nm-openvpn write to TUN/TAP : Invalid argument (code=22) jonaskellens Linux - Newbie 0 08-24-2009 04:49 AM OpenVPN - tun - tap - tunnels leamassiot Linux - Networking 40 08-12-2009 10:36 AM Need help on TUN/TAP vinodl Linux - Networking 1 06-22-2009 12:18 PM Tun/Tap issue minasafwat Linux - Kernel 0 11-14-2006 02:11 AM LinuxQuestions.org > Forums > Linux Forums > Linux - Server All times are GMT -5. 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Openvpn: Write to Tun/tap : Invalid Argument (Code=22)

Source: https://www.linuxquestions.org/questions/linux-server-73/openvpn-tun-tap-806675/

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