ssh_ exchange-identification: Connection closed by remote host

Linux and Unix-Like Linux
1

Dear All,

Recently our server has been giving the error:

"ssh_ exchange-identification: Connection closed by remote host"

The error causes the server to become in accessible via ssh and the services are stopped/hung. The server has to be restarted to make it working normal again.
The server is working on RHEL3.

Pls. help in finding the solution to the problem.

Regards,
Vinod.

2

It's found that the server gives some SCSI related error. The problem occurs sometimes after 2 months and sometimes every week. Should i replace the server or what? Pls. suggest ?

Regards,
Vinod.

3

vguleria,

Did you change the network interface of the system? or the IP address of the system? Are you accessing that on other host when that error occurs? If yes once you rebooted generate ssh key for the system and copy that to the host your having errors.

4

Thanks for the reply csonhand,

I also have the trace of the server's /var/secure/log/messages which is something related to SCSI:

Sep 17 07:42:59 <MyHostName> kernel: scsi1:0:0:0: Attempting to abort cmd f6c94000: 0x2a 0x0 0x6 0xa3 0x7f 0x34 0x0 0x0 0x8 0x0
Sep 17 07:42:59 <MyHostName> kernel: scsi1: At time of recovery, card was not paused
Sep 17 07:42:59 <MyHostName> kernel: >>>>>>>>>>>>>>>>>> Dump Card State Begins <<<<<<<<<<<<<<<<<
Sep 17 07:42:59 <MyHostName> kernel: scsi1: Dumping Card State at program address 0x27 Mode 0x22
Sep 17 07:42:59 <MyHostName> kernel: Card was paused
Sep 17 07:42:59 <MyHostName> kernel: HS_MAILBOX[0x0] INTCTL[0xc0] SEQINTSTAT[0x0] SAVED_MODE[0x11]
Sep 17 07:42:59 <MyHostName> kernel: DFFSTAT[0x31] SCSISIGI[0x0] SCSIPHASE[0x0] SCSIBUS[0x0]
Sep 17 07:42:59 <MyHostName> kernel: LASTPHASE[0x1] SCSISEQ0[0x0] SCSISEQ1[0x12] SEQCTL0[0x10]
Sep 17 07:42:59 <MyHostName> kernel: SEQINTCTL[0x0] SEQ_FLAGS[0xc0] SEQ_FLAGS2[0x0] SSTAT0[0x0]
Sep 17 07:42:59 <MyHostName> kernel: SSTAT1[0x0] SSTAT2[0x0] SSTAT3[0x0] PERRDIAG[0x0]
Sep 17 07:42:59 <MyHostName> kernel: SIMODE1[0xa4] LQISTAT0[0x0] LQISTAT1[0x0] LQISTAT2[0x0]
Sep 17 07:42:59 <MyHostName> kernel: LQOSTAT0[0x0] LQOSTAT1[0x0] LQOSTAT2[0x0]
Sep 17 07:42:59 <MyHostName> kernel:
Sep 17 07:42:59 <MyHostName> kernel: SCB Count = 32 CMDS_PENDING = 1 LASTSCB 0x18 CURRSCB 0x18 NEXTSCB 0x0
Sep 17 07:42:59 <MyHostName> kernel: qinstart = 45712 qinfifonext = 45712
Sep 17 07:43:00 <MyHostName> kernel: QINFIFO:
Sep 17 07:43:00 <MyHostName> kernel: WAITING_TID_QUEUES:
Sep 17 07:43:00 <MyHostName> kernel: Pending list:
Sep 17 07:43:00 <MyHostName> kernel: 9 FIFO_USE[0x0] SCB_CONTROL[0x64] SCB_SCSIID[0x5]
Sep 17 07:43:00 <MyHostName> kernel: Total 1
Sep 17 07:43:00 <MyHostName> kernel: Kernel Free SCB list: 4 26 12 8 20 3 11 28 27 19 7 6 29 25 31 17 1 23 24 21 15 22 18 13 5 0 30 10 2 16 14
Sep 17 07:43:00 <MyHostName> kernel: Sequencer Complete DMA-inprog list:
Sep 17 07:43:00 <MyHostName> kernel: Sequencer Complete list:
Sep 17 07:43:00 <MyHostName> kernel: Sequencer DMA-Up and Complete list:
Sep 17 07:43:00 <MyHostName> kernel:
Sep 17 07:43:00 <MyHostName> kernel: scsi1: FIFO0 Free, LONGJMP == 0x80ff, SCB 0x0
Sep 17 07:43:00 <MyHostName> kernel: SEQIMODE[0x3f] SEQINTSRC[0x0] DFCNTRL[0x0] DFSTATUS[0x89]
Sep 17 07:43:00 <MyHostName> kernel: SG_CACHE_SHADOW[0x2] SG_STATE[0x0] DFFSXFRCTL[0x0]
Sep 17 07:43:00 <MyHostName> kernel: SOFFCNT[0x0] MDFFSTAT[0x5] SHADDR = 0x00, SHCNT = 0x0
Sep 17 07:43:00 <MyHostName> kernel: HADDR = 0x00, HCNT = 0x0 CCSGCTL[0x10]
Sep 17 07:43:00 <MyHostName> kernel: scsi1: FIFO1 Free, LONGJMP == 0x81ed, SCB 0x18
Sep 17 07:43:00 <MyHostName> kernel: SEQIMODE[0x3f] SEQINTSRC[0x0] DFCNTRL[0x4] DFSTATUS[0x89]
Sep 17 07:43:00 <MyHostName> kernel: SG_CACHE_SHADOW[0x2] SG_STATE[0x0] DFFSXFRCTL[0x0]
Sep 17 07:43:00 <MyHostName> kernel: SOFFCNT[0x0] MDFFSTAT[0x5] SHADDR = 0x00, SHCNT = 0x0
Sep 17 07:43:00 <MyHostName> kernel: HADDR = 0x00, HCNT = 0x0 CCSGCTL[0x10]
Sep 17 07:43:00 <MyHostName> kernel: LQIN: 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0
Sep 17 07:43:00 <MyHostName> kernel: scsi1: LQISTATE = 0x0, LQOSTATE = 0x0, OPTIONMODE = 0x42
Sep 17 07:43:00 <MyHostName> kernel: scsi1: OS_SPACE_CNT = 0x20 MAXCMDCNT = 0x0
Sep 17 07:43:00 <MyHostName> kernel: SIMODE0[0xc]
Sep 17 07:43:00 <MyHostName> kernel: CCSCBCTL[0x0]
Sep 17 07:43:00 <MyHostName> kernel: scsi1: REG0 == 0x18, SINDEX = 0x122, DINDEX = 0xe1
Sep 17 07:43:00 <MyHostName> kernel: scsi1: SCBPTR == 0x4, SCB_NEXT == 0x0, SCB_NEXT2 == 0x0
Sep 17 07:43:00 <MyHostName> kernel: CDB 2a 0 2 80 a9 ba
Sep 17 07:43:00 <MyHostName> kernel: STACK: 0x15 0x125 0x125 0x125 0x125 0x125 0x125 0x29
Sep 17 07:43:00 <MyHostName> kernel: <<<<<<<<<<<<<<<<< Dump Card State Ends >>>>>>>>>>>>>>>>>>
Sep 17 07:43:00 <MyHostName> kernel: DevQ(0:0:0): 0 waiting
Sep 17 07:43:00 <MyHostName> kernel: DevQ(0:4:0): 0 waiting
Sep 17 07:43:00 <MyHostName> kernel: (scsi1:A:0:0): Device is disconnected, re-queuing SCB
Sep 17 07:43:00 <MyHostName> kernel: Recovery code sleeping
Sep 17 07:43:00 <MyHostName> kernel: (scsi1:A:0:0): Abort Tag Message Sent
Sep 17 07:43:00 <MyHostName> kernel: (scsi1:A:0:0): SCB 9 - Abort Completed.
Sep 17 07:43:00 <MyHostName> kernel: Recovery SCB completes
Sep 17 07:43:00 <MyHostName> kernel: found == 0x1
Sep 17 07:43:00 <MyHostName> kernel: Recovery code awake

thanks,
VG.