telnet : Connection closed by foreign host

[GRANDIERE]

Impossible to connect to my serveur with telnet ou ftp.
I can ping the server.
The server has tow interface lan0 et lan2. I can connect with telnet from a another server whitch uses the lan2 interface. But it is impossible with the lan0.

First Error Message :
RPU0H057 >/ #telnet 150.62.104.68
Trying...
Connected to 150.62.104.68.
Escape character is '^]'.
Local flow control off
Connection closed by foreign host.

Second Error Message :
RPU0H057 >/ #telnet 150.62.104.68
Trying...
telnet: Unable to connect to remote host: Connection refused

Le telnet deamon is started
prisme4:/var/adm/syslog#ps -ef |grep telnet
root 15039 14956 1 17:23:51 pts/5 0:00 grep telnet
root 14829 690 0 16:39:19 pts/ta 0:00 telnetd

I started the inet
prisme4:#inetd -b
And saw that messages in the logs :
prisme4:/var/adm/syslog#tail syslog.log
Mar 29 16:54:08 prisme4 telnetd[14919]: getpid: peer died: Error 0
Mar 29 16:55:50 prisme4 nmbd[10368]: [2006/03/29 16:55:50, 0] nmbd/nmbd_responserecordsdb.c:(234)
Mar 29 16:55:50 prisme4 nmbd[10368]: find_response_record: response packet id 32843 received with no matching record.
Mar 29 17:01:01 prisme4 rlogind[14796]: Login failure (exit(130) from login(1))
Mar 29 17:12:16 prisme4 syslog: inetd sendsig: entered, sig=4
Mar 29 17:12:16 prisme4 syslog: inetd sendsig: exiting
Mar 29 17:12:16 prisme4 inetd[690]: Extended connection logging enabled
Mar 29 17:12:16 prisme4 inetd[690]: Select() returned:n=-1,errno=4:Interrupted system call
Mar 29 17:12:16 prisme4 inetd[690]: Entered for(;;) loop.
Mar 29 17:12:16 prisme4 inetd[690]: About to select()...

Thanks for help.

GRANDIERE

[Steven E. Protter]

shalom,

ifconfig lan0 lan1 lan2 in sequence ifconfig lan.

Check /etc/inetd.conf

is telnet enabled. Is ftp

inetd -c
# restarts

SEP

[GRANDIERE]

Thanks for your response :

prisme4:/#ifconfig lan0
lan0: flags=843
inet 150.62.104.68 netmask fffff800 broadcast 150.62.111.255
prisme4:/#ifconfig lan2
lan2: flags=1843
inet 192.10.10.4 netmask ffffff00 broadcast 192.10.10.255

Since i wrote my first message, the telnet service works again. But the service work and not for 2 days : i think the service will fail again ...

I can say that the telnet service is enable because i can connect from another serveur.
prisme4:/#more inetd.conf
[...]
telnet stream tcp nowait root /usr/lbin/telnetd telnetd
[...]


GRANDIERE

[DCE]

Grandiere,

I have seen this scenario caused by a couple different issues.

/, /tmp, or /var/tmp are full.

maximum number of sessions is maxed out

nproc is maxed out

a runaway process is usung up too many system resources.

[GRANDIERE]

***************************************
No FS are full :

prisme4:/#bdf
Filesystem kbytes used avail %used Mounted on
/dev/vg00/lvol3 212992 62280 149584 29% /
/dev/vg00/lvol1 298928 34784 234248 13% /stand
/dev/vg00/lvol7 4718592 452888 4232408 10% /var
/dev/vg00/lvol6 884736 766544 117368 87% /usr
/dev/vg02/lv_travail
5120000 1977314 2946604 40% /travail
/dev/vg00/lvol5 212992 4152 207248 2% /tmp
/dev/vg01/lv_s1_prisme4_sybsystemprocs_v12
90112 83045 6633 93% /sybsystemprocs_v12
/dev/vg01/lv_sybase12
1024000 630190 369248 63% /sybase12
/dev/vg00/lvol4 1228800 820328 405312 67% /opt
/dev/vg01/fs_backup_01
409600 156605 237226 40% /netbackup
/dev/vg01/lv_lk_ 12288000 6858344 5261470 57% /lk_
/dev/vg00/lvol8 32768 2872 29712 9% /home
/dev/vgdump/lv_dump
143351808 98690920 44312624 69% /dump
/dev/vg02/lv_alim 15360000 7382342 7728358 49% /donnees
prisme2:/dump 215027712 181691528 33075992 85% /dump_prisme2


***************************************
And the CPU seems to be quit :
prisme4:/#top

System: prisme4 Wed Mar 29 18:52:29 2006
Load averages: 0.05, 0.10, 0.11
105 processes: 103 sleeping, 2 running
Cpu states:
CPU LOAD USER NICE SYS IDLE BLOCK SWAIT INTR SSYS
0 0.00 0.0% 0.0% 0.0% 100.0% 0.0% 0.0% 0.0% 0.0%
1 0.10 0.2% 0.0% 0.2% 99.6% 0.0% 0.0% 0.0% 0.0%
--- ---- ----- ----- ----- ----- ----- ----- ----- -----
avg 0.05 0.0% 0.0% 0.2% 99.8% 0.0% 0.0% 0.0% 0.0%

Memory: 33668K (20296K) real, 122748K (81572K) virtual, 61868K free Page# 1/3

CPU TTY PID USERNAME PRI NI SIZE RES STATE TIME %WCPU %CPU COMMAND
0 ? 33 root 152 20 1856K 0K run 79:47 1.13 1.13 vxfsd


How can i know if maximum number of sessions is maxed out.

Thanks again.

GRANDIERE

[DCE]

You can monitor the number of processes and sessions real time with glance. If you have measureware installed, you can look at the history with perfview.

[GRANDIERE]

The problem came again !
I don't think that problem commes cause a runaway process is usung up too many system resources : when i connecte the server by another network interface the telnet session works well.

Has anyone another idea ?

Thanks.

GRANDIERE

[Tom Henning · Accepted solution]

As mentioned in another thread (Sorry, I cannot find the reference at the moment) is it possible that another box has duplicated the 150.62.104.68 address? A simple test would be, while telnet is not working, to disconnect the network cable to the server and ping the address. If the ping works, you have a duplicate address.

[GRANDIERE]

Hi Tom Henning,

You know what you are a superman !

That's my problem.

Thanks a lot !!!!

By

[GRANDIERE]

To close the thread.