Windows Server

Dwayne · Guest

I know that the VPN connection is not timing me out and I have the TN3270
service in HIS2000 set to infite timeout. Could our old 9121 mainframe be
pushing me off after an hour or so?
Thoughts?

Neil Pike · Guest

Dwayne,

It certainly could. A sniffer trace would show which end is doing the
dsiconnect.

John Chambers · Guest

While this doesn't answer the question it may be an acceptable workaround.
By default the TCP/IP keepalive interval is 2 hours (7,200,000
milliseconds), so any idle connections will not have any TCP/IP packets
being exchanged for this interval. You could modify this value to something
like 90 seconds (90,000 milliseconds), that way you would know if the
problem is a lack of TCP/IP traffic or is related to the mainframe. Check
out MSKB Q183786 for details on the registry changes required on the HIS
server. Changes to the keepalive timer also has the added benefit outlined
in the KB Article. We use this setting on all of our production HIS
servers.

John Chambers

"Dwayne" <dferet@hotmail.com> wrote in message
news:eeThlZUCFHA.3784@TK2MSFTNGP15.phx.gbl...
I know that the VPN connection is not timing me out and I have the TN3270
service in HIS2000 set to infite timeout. Could our old 9121 mainframe be
pushing me off after an hour or so?
Thoughts?

Dwayne · Guest

I changed the TN3270 timeout in registry to 1200 from 120.
Thanks, we shall see what happens.

Dwayne

"John Chambers" <JohnC@test01.com> wrote in message
news:ekeiQGwCFHA.464@TK2MSFTNGP15.phx.gbl...

Dwayne · Guest

Also does any one know what to change in the registry to force HIS2000 to
use keepalives?

"Dwayne" <dferet@hotmail.com> wrote in message
news:hw7Nd.12014$cg5.1213@fe12.lga...

Dwayne · Guest

I read the article listed but am unsure where exactly to stick the new key
in the registry or if this works with HIS2000 and the article is talking
about SNA server. I assume I have to add something to regisrty in order to
turn on the keepalives.
The error I end up getting is "02 Requested LU unavailable. I found up to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
but am sure what to do next.

Can anyone assist?

The article wrote:
To change these parameters, perform the following procedure: 1. Start
Registry Editor (REGEDT32.EXE), and to the following subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services

2. Add a value to the key described in the appropriate entry below, by
Add Value from the Edit menu, typing in the value, and using the "Data Type"
check box to set the value type.
3. Click OK.
4. Quit Registry Editor and restart the system for the changes to take
effect.
All of the TCP/IP parameters are registry values located under one of two
different subkeys of HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services: .
Tcpip\Parameters
. <Adapter Name>\Parameters\Tcpip
where <Adapter Name> refers to the subkey for a network adapter that TCP/IP
is bound to, such as Lance01. Values under the latter key(s) are specific to
each adapter. Parameters for which there may be both a DHCP and
statically-configured value may or may not exist depending on whether the
system/adapter is DHCP configured and/or static override values have been
specified. A restart of the system is required for a change in any of these
parameters to take effect.
KeepAliveTime
Key: Tcpip\Parameters
Value Type: REG_DWORD - Time in milliseconds
Valid Range: 1 - 0xFFFFFFFF
Default: 7,200,000 (two hours)
Description: The parameter controls how often TCP attempts to verify
that an idle connection is still intact by sending a keep alive packet.
If the remote system is still reachable and functioning, it will
acknowledge the keep alive transmission. Keep alive packets are not sent
by default. This feature may be enabled on a connection by an
application.
NOTE: The following KeepAliveInterval does not need to be changed,
though it is provided below for reference purposes.
KeepAliveInterval
Key: Tcpip\Parameters
Value Type: REG_DWORD - Time in milliseconds
Valid Range: 1 - 0xFFFFFFFF
Default: 1000 (one second)
Description: This parameter determines the interval separating keep
alive retransmissions until a response is received. After a response is
received, the delay until the next keep alive transmission is again
controlled by the value of KeepAliveTime. The connection will be aborted
after the number of retransmissions specified by
TcpMaxDataRetransmissions has gone unanswered.
WORKAROUND
The optimal solution is to modify the Windows NT TCP/IP driver's
KeepAliveTime registry parameter where the SNA Server TN3270 Service is
running, as described below, and then restart Windows NT.

NOTE: The SNA Server TN3270 Service also has an "Idle Timeout" parameter
that will automatically end a TN3270 client session that is idle for the
timeout interval (which defaults to 120 minutes). However, this is a less
optimal solution although this feature may be useful in some customer
circumstances.
"John Chambers" <JohnC@test01.com> wrote in message
news:ekeiQGwCFHA.464@TK2MSFTNGP15.phx.gbl...

Neil Pike · Guest

Assuming Kb article 183786 applies to HIS as well as SNA Server (and it
probably does) then it looks like the TN3270 service always does keep-alives.

---

The TN3270E specification (RFC 1647) section 13.3 suggests two possible methods
for TN3270 client and server to implement the keepalive mechanism: the Telnet
IAC NOP command, or the Telnet DO TIMING-MARK option. However, RFC 1647 does
not require that any form of keep-alive mechanism be employed by either clients
or servers. The SNA Server TN3270 Service chooses not to implement its own
keep-alive mechanism, leaving it up to the administrator to tune the Windows NT
TCP/IP KeepAliveTime as described above.

Neil Pike · Guest

Dwayne,

The location will depend on your O/S. For example on XP each nic interface is
enumerated like the below

C:\>reg query
hklm\system\currentcontrolset\services\tcpip\parameters\interfaces

! REG.EXE VERSION 3.0

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{05B7C508-89B4-470E-9932-EFAFB483FD02}

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{27D785FE-5634-43FC-AEF9-669CD4E3213E}

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{2A651C1E-9B49-4B12-B33F-D4655B37820F}

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{2ACE9C2B-6047-478D-9423-FEEEE4AD223D}

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{2EE35AE6-FFF5-458A-A288-743C420CE4AD}

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{45B2E7AC-F8CF-4983-9B8D-0F3D40295757}

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{4EF3CDD2-1FA3-42F1-BD82-C914AEA98A1F}

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{7A84324F-94D6-47CC-9371-6CA56A771A4E}

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{A6DFDFF0-09D6-4744-952E-5DEF5A5F0F51}

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{DC214724-0064-4F98-828B-6803A5A7F62D}

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{F03EA9E2-F089-46EF-8C36-089C772800F0}

HKEY_LOCAL_MACHINE\system\currentcontrolset\services\tcpip\parameters\interface
s\{F3CCB90D-78EB-42F4-B5B4-29D1EECA568B}

John Chambers · Guest

Dwayne,

It works just fine with HIS2000. Under
HKLM\System\CurrentControlSet\Services\Tcpip\Parameters, right click and add
a new DWORD value. The name of the key should be KeepAliveTime. Then,
double click on it and set the value to 90,000 decimal. I have always put
it in this location rather than under the individual LAN Adapters and it has
worked without any problems. You will probably need to restart the TN3270
service for this to take effect. (I would just reboot the HIS server just
to be sure). There aren't any other HIS registry settings that need to be
done for this to take effect.

John Chambers

"Dwayne" <dferet@hotmail.com> wrote in message
news:yOoNd.2744$jA.807@fe11.lga...
I read the article listed but am unsure where exactly to stick the new key
in the registry or if this works with HIS2000 and the article is talking
about SNA server. I assume I have to add something to regisrty in order to
turn on the keepalives.
The error I end up getting is "02 Requested LU unavailable. I found up to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
but am sure what to do next.

Can anyone assist?

The article wrote:
To change these parameters, perform the following procedure: 1. Start
Registry Editor (REGEDT32.EXE), and to the following subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services

2. Add a value to the key described in the appropriate entry below, by
Add Value from the Edit menu, typing in the value, and using the "Data Type"
check box to set the value type.
3. Click OK.
4. Quit Registry Editor and restart the system for the changes to take
effect.
All of the TCP/IP parameters are registry values located under one of two
different subkeys of HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services: .
Tcpip\Parameters
. <Adapter Name>\Parameters\Tcpip
where <Adapter Name> refers to the subkey for a network adapter that TCP/IP
is bound to, such as Lance01. Values under the latter key(s) are specific to
each adapter. Parameters for which there may be both a DHCP and
statically-configured value may or may not exist depending on whether the
system/adapter is DHCP configured and/or static override values have been
specified. A restart of the system is required for a change in any of these
parameters to take effect.
KeepAliveTime
Key: Tcpip\Parameters
Value Type: REG_DWORD - Time in milliseconds
Valid Range: 1 - 0xFFFFFFFF
Default: 7,200,000 (two hours)
Description: The parameter controls how often TCP attempts to verify
that an idle connection is still intact by sending a keep alive packet.
If the remote system is still reachable and functioning, it will
acknowledge the keep alive transmission. Keep alive packets are not sent
by default. This feature may be enabled on a connection by an
application.
NOTE: The following KeepAliveInterval does not need to be changed,
though it is provided below for reference purposes.
KeepAliveInterval
Key: Tcpip\Parameters
Value Type: REG_DWORD - Time in milliseconds
Valid Range: 1 - 0xFFFFFFFF
Default: 1000 (one second)
Description: This parameter determines the interval separating keep
alive retransmissions until a response is received. After a response is
received, the delay until the next keep alive transmission is again
controlled by the value of KeepAliveTime. The connection will be aborted
after the number of retransmissions specified by
TcpMaxDataRetransmissions has gone unanswered.
WORKAROUND
The optimal solution is to modify the Windows NT TCP/IP driver's
KeepAliveTime registry parameter where the SNA Server TN3270 Service is
running, as described below, and then restart Windows NT.

NOTE: The SNA Server TN3270 Service also has an "Idle Timeout" parameter
that will automatically end a TN3270 client session that is idle for the
timeout interval (which defaults to 120 minutes). However, this is a less
optimal solution although this feature may be useful in some customer
circumstances.
"John Chambers" <JohnC@test01.com> wrote in message
news:ekeiQGwCFHA.464@TK2MSFTNGP15.phx.gbl...

Dwayne · Guest

This seems to have done the trick, maintained a connection with a 8 hour
idle period.

Thanks so much.

I'm very thankful for a group such as this with people helping people.

Dwayne

"John Chambers" <JohnC@test01.com> wrote in message
news:O1B45qSDFHA.3928@TK2MSFTNGP15.phx.gbl...

John Chambers · Guest

Glad it worked. FYI, here is one possible scenario that we ran into that
caused this same type of problem. We had users connecting through a
firewall (may VPN connections are handled by a firewall like a Cisco PIX)
and they would also experience these types of timeouts. It turned out that
while the VPN connection would remain active the firewall had some timing
settings in it to purge or terminate any TPC/IP Socket connections that were
idle (no TCP/IP traffic) for over 1 hour. That is one of the reasons we
enabled keepalives at the 90 second interval.

John Chambers

"Dwayne" <dferet@hotmail.com> wrote in message
news:esi4c9SDFHA.1392@tk2msftngp13.phx.gbl...
This seems to have done the trick, maintained a connection with a 8 hour
idle period.

Thanks so much.

I'm very thankful for a group such as this with people helping people.

Dwayne

"John Chambers" <JohnC@test01.com> wrote in message
news:O1B45qSDFHA.3928@TK2MSFTNGP15.phx.gbl...

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