Solution for "allnetworkportsinuse" in telnet

The solution of & quot; allnetworkportsinuse & quot; appears in telnet-Linux Enterprise Application-Linux server application information. For details, refer to the following. Due to unexpected damage to the Linux system, telnet is not allowed after recovery. As soon as the client connects to the Linux server, the string "telnetd: all network ports in use" is returned, and the SSH connection is also invalid! It was initially suspected that the port was occupied by another program, but port 23 was not used when it was viewed using netstat-anp. What is the reason? View the/var/log/secure File and find some useful information, as shown below:

[Root @ localhost ~] # Cat/var/log/secure

... Aug 20 18:12:05 localhost sshd [15243]: Accepted password for hyg from: ffff: 192.168.1.217 port 3980 ssh2

Aug 20 18:12:11 localhost sshd [15243]: error: openpty: No such file or directory Aug 20 18:12:11 localhost sshd [15348]: error: session_pty_req: session 0 alloc failed

It seems that there is a problem with the virtual terminal. Check the mount and find that the pts file system is not mounted. generally, this file system is automatically mounted. Open the/etc/fstab file and check that there are only a few lines:

/Dev/mapper/VolGroup00-LogVol00/ext3 rw 0 0
/Dev/proc rw 0 0

/Dev/fd0/media/floppy auto pamconsole, exec, noauto, managed 0 0
/Dev/hdc/media/cdrom1 auto pamconsole, exec, noauto, managed 0 0

This is automatically created when the system recovers automatically. The pts file system is not loaded, and other systems are not mounted. Refer to the fstab file of the normal system and modify it as follows:

/Dev/mapper/VolGroup00-LogVol00/ext3 rw 0 0
LABEL =/boot ext3 defaults 1 2
/Dev/devpts/dev/pts devpts gid = 5, mode = 620 0 0
/Dev/shm tmpfs defaults 0 0
/Dev/proc defaults 0 0
/Dev/sys sysfs defaults 0 0
/Dev/VolGroup00/LogVol01 swap defaults 0 0

/Dev/fd0/media/floppy auto pamconsole, exec, noauto, managed 0 0
/Dev/hdc/media/cdrom auto pamconsole, exec, noauto, managed 0 0

After reboot, everything is normal!