Maxwell G -- Corrected Script to Start a VNC Server

Many users who place their Maxwell G's into a lab find it inconvenient to operate the Maxwell G in the lab itself.  So they exporting a desktop onto a Windows or Linux desktop computer in a more comfortable location.

The best tool for this is VNC.

VNC requires that the user login to a command prompt (usually via SSH or via a locally attached keyboard/monitor) in order to initiate a VNC server.  The server, when started, announces address and port/desktop number information that needs be fed to the VNC client.

That server can then be accessed from a VNC client using that number information.

Getting VNC started can be somewhat difficult, particularly if there have been previous VNC sessions.

To make things easier we have created a shell script that will clean out an stale VNC server information and start a new, clean VNC service.

That script is in a file named /home/maxwell/bin/startvncserver

However due to an error in one of the programs we use when setting up a new Maxwell G the content of that script file was damaged.

As of this date - May 7, 2013 - we have corrected this for new machines.

However, this file needs to be manually replaced on older machines.

Below is a copy of the corrected script.

Please save a copy of the damaged script and then replace the contents of the file /home/maxwell/bin/startvncserver with the contents shown below

#!/bin/bash

PATH="/sbin:/usr/sbin:/bin:/usr/bin"
export PATH

echo "Please ignore any warning messages about the non-existence of"
echo "xauth/.Xauthority files."

for s in `vncserver -list | awk '/^:([[:digit:]*])/ { print $1; }'` ; do
  vncserver -kill ${s}
done

if [ -d ~/.vnc ] ; then
  rm -f ~/.vnc/*log
fi

vncserver -geometry 1240x960

Maxwell G -- Trying out the new Maxwell G and Maxwell Pro -- looks like I got the Russian version?

Question:  (by Shamrock)  When I install a keyboard, video, and mouse to boot up Maxwell G to get DHCP to give it an IP address, I notice that some strange characters, that look like Russian (or some other garbage characters) appear on the screen. If I ignore  this, the Maxwell G boots up correctly, but what is causing it and is it a real problem?

Answer:  (Deepak N.)  There are two issues:

#1 During the boot-up sequence some strange characters are displayed on the video screen for a few seconds.

These are transient ? normal, correct video will resume within a few seconds. (The resumption of proper video operation may be masked if the video re-synchronization issue, described in the next section occurs.)

This issue is caused by a bug in the Linux kernel and its start-up scripts.

#2 Some video monitors have difficulty synchronizing with the video output of the Maxwell Pro and Maxwell G.

On some older video monitors the monitor loses synchronization with the Maxwell Pro or Maxwell G during the boot-up sequence.

Many monitors indicate this by constantly switching between input sources looking for a signal, other monitors display an indication saying that they can find no input signal.  This occurs mainly with older design flat-screen monitors.

This condition usually may be cleared by done any of the following:
-Power cycling the video monitor off then on.
-Using a button on the monitor to manually switch to an unused video source and then back to the source used by the Maxwell.

Mini Maxwell -- UDP Filters on Two Different Bands

Question:  (by Shamrock)  I'm trying to establish two different UDP filters on two different bands. When I submit a filter to be active individually the network traffic is filtered correctly, but when I activate both filters at the same time one of the filters does not see the  desired traffic. What am I doing wrong?

 Answer: (by MrFixIt) I think no one at InterWorking Labs answered the question because no one understood it :-) Let me give you an example of UDP traffic.

If you are going to filter all UDP traffic that has to happen in one band. However you impair it in that band (e.g. drop it, duplicate it), it is impaired and exits out the data interface. You cannot do further impairments in another band.

Now, you could pick another band and do some impairments on the non-UDP traffic, such as TCP, so that you are applying drops to all UDP traffic from A to B in band one, and then re-ordering to all TCP traffic from A to B in band two. Does this make  sense?

BTW ... there's a good example in the Filters section of the User Guide on the website under Support.

Mini Maxwell -- How do I Control Mini Maxwell from my own script?

Question: (by Shamrock) Is there a way that I can send commands to Mini Maxwell remotely? Or do I have to use the GUI? Is there any type of command line interface that I could use?

Answer One:(by Sapient)  You can actually set up commands in a spreadsheet and then run that remotely. There's a video called:

"Increasing Network Packet Loss Rate
Automatically"

Answer Two:  (by MrFixIt) Actually there is also a Python program that you can use. You need to download it from the Customer Downloads section at support.iwl.com.

Basically, you can bypass the Mini Maxwell web pages and have the Python program take control. You can start the program from a CLI and it works with any framework written in Tcl, Perl, Python, etc.

You need Rev 12 or later of Mini Maxwell and Python v2.6 or later.

Mini Maxwell -- Is it possible to get Mini Maxwell in a rack mount?

Question:  (by Shamrock)  We have been successfully using Mini Maxwell, but sometimes the little box gets misplaced! It would be better in our environment if we had a rack mount package for Mini Maxwell to avoid "shrinkage". Anyone know?

Answer:  (by Rico)  Hi Shamrock,

My name is Rico Sumarna and I am the Accounts Executive here at IWL. I am very please to announce that we have a rack mount version of Mini Maxwell!

This configuration will allow you to bolt Mini Maxwell directly to your rack and will help you avoid "shrinkage". Your Mini Maxwell will now be safe and secure.

If you would like to discuss this option further please give me a call at 831-460-7010 x102.

I look forward to hearing from you.

Rico

Maxwell Pro -- What monitors work with Maxwell Pro?

Answer:  (by ChrisW)  InterWorking Labs has tested Maxwell Pro with these monitors:

ASUS VK246H
Samsung T240HD

We believe any monitor manufactured within the last five years should work fine. Older monitors will not work.

Maxwell Pro -- Filtering traffic by ports?

Question:  (by DKorzuchin)  Hi, I have a question about the Maxwell pro--I want to filter traffic based not only on the ip address of two machines but particular ports as well. Is this possible?

Answer:  (by JimLogajan)  You can create a filter matching one, two, or a range of port numbers (where the range is set using a bit mask) by setting parameters in the "IPv4 and LAN Filter" or "IPv6 and LAN Filter" dialogs available under the "Flow Selector" dialog.

Alternately, you can use the "Match Expression" dialog to filter on up to four source or destination ports by setting the appropriate offset into the TCP or UDP headers and setting the desired match values.

If that isn't enough, you can create up to 64 flows (click on the root "System" node in the selection tree in the left panel of the main GUI and set the "Number of Flows" field,) with each flow set up with a subset of the desired ports using one of the previous mechanisms. This would provide up to 256 ports to be selectively chosen for the desired impairments. This approach is somewhat tedious to set up from the GUI but generally much easier using a script that takes advantage of the Remote API.

Maxwell Pro -- Packet drop after a sequence of packets?

Question:  (by Choco)  I want to customize my emulated burst traffic by regularly dropping packets for every burst. How do I tell maxwell, for example, that I want it to drop x packets every 10 packets

Answer: (by Jim Logajan) You can perform periodic impairments like that using Maxwell's "Flow Triggering" mechanism. It allows you to define a flow that impairs every nth packet that matches the flow. For example, to drop X packets after every 10 packets, you would first select the "Flow Selector" branch for a flow (such as Flow 0). Then place a check mark in one of the options that are labeled "LAN Filter", such as "IPv4 and LAN Filter".

The "Flow Triggering" button should now be active - clicking it will display the flow triggering dialog.

Select either "Basic" or "TcpUdp" trigger type. The GUI contains an explanation of their meanings; if in doubt select "Basic".

Since you want to drop every 10 packets you would enter 10 into the "Number of Packets in Initial Lull" field. Then enter your X value into the "Number of Packets to Impair" field. If you want the drops to go on forever then leave the "Number of Trigger Repetitions" field at zero.

Now click the "Apply" button to start the filtering. But wait - we haven't actually told Maxwell that we want packets in Flow 0 to be dropped! Click on flow zero's "Drop" branch. Check mark the "Activate Packet Drop" field and enter 100% into the "Drop Probability" field. Maxwell will now begin dropping X packets after every 10 packets.

If you need to narrow the type of packets that are included in the drops you would need to supply additional filter criteria in the "Flow Selector" dialog for that flow.

Maxwell Pro -- Remote login to Maxwell Pro

Question:  (by Admin)  I have a Maxwell Pro and we are now working with a team in India. I am located in Milpitas California along with the Maxwell Pro. My team in India wants to utilize Maxwell Pro as well.

Is there a way that the Indian team can remotely login to my Maxwell Pro and use it?

Answer:  (by Admin) Remote access control could be done using X-Windows, VNC, or via the Maxwell TCP/IP control connection on its default port. Since most likely there are firewalls involved, unless you have a VPN between the two sites, you'll generally need to use something like an ssh tunnel to the desired service port on the Maxwell (i.e. port 6000 for X-Windows, 590X for VNC display X, 7021 for Maxwell TCP/IP) and then have the client connect to the local port that was chosen.

What sort of network connection constraints do you have, what kind of control does the remote site need (running protocol tests, running network impairments, shell command control and/or GUI control) and which of the mechanisms mentioned above, if any, are likely candidates that would fit your needs?

Maxwell Pro -- Testing the TCP Push Bit

Question:  (by Admin for Choco)  I would like to test that the sending side sends a PUSH bit in the request packet. Is there a way I can do that without purchasing your TCP test suite (we don't have the budget right now)?

Note that RFC 1122 states:

A TCP MAY implement PUSH flags on SEND calls.  If PUSH flags
are not implemented, then the sending TCP:
(1) must not
buffer data indefinitely, and
(2) MUST set the PSH bit in the
last buffered segment (i.e., when there is no more queued data to be
sent).

Just trying to run some experiments on that.

Answer:  (by Admin)  Hi Choco, One thing you could do is play around with the ALTER impairment. You can modify a specific packet right from the UI. I've been using it for various packet manipulations.

Also, I've got the Maxwell TCP Test package and there is a test in there to do what you want. But you can do it with the ALTER impairment.

SilverCreek -- Trap Interval for Net-SNMP (a little off the SilverCreek topic)

Question:  (by Tiny Timmy)  I've been working with the link-up/link-down traps in Net-SNMP, and notice that they only update every 60 seconds.

Supposedly you can overwrite this in the configuration file, but when I have tried to make it every two seconds, it just goes back to 60 seconds. In other words, the settings are not honored.

Has any one figured out a way around this?

Answer One:  (by PumpkinJason)  Are you saying the traps are delayed while being sent out by your snmpd daemon, or you actually meant the traps are just logged with a delay by snmptrapd?

What configuration directive you used to make it to "2 seconds" interval?

Answer Two:  (by TinyTimmy)  The problem with net-snmp is that it checks the link status only once every 60 seconds.

That means that if you yank the network cable out you will wait anywhere between 0 and 59.999 seconds before the net-snmp agent emits a link down trap.

Or, if the link is already down and you insert a network cable you wait From 0 to 59.999 seconds before the agent emits a link-up trap.  And worse, if you manage to yank the cable and then put it back again so that both of those events occur between the checks by the net-snmp agent, *no* link-down or link-up trap will be emitted at all - only silence.

There are directives in net-snmp to alter that polling period.  But they don't work; they do not change the one minute cycle.

This issue has absolutely nothing about a trap receiver - I watched this Emission (or non-emission) of traps using Wireshark.

Answer Three:  (by PumpkinJason) I suspect this has something to do with DNS resolution time? 

If you are using host domain name for trapsink insnmpd.conf, changeit to IP address to see if it makes any difference?

Answer Four:  (by TinyTimmy)  I have been using the IP address and the DNS is resolving in a couple of milliseconds, so that is not it.

Answer Five:  (by Sandiyago) For the default linkUpDownNotification trap, current Net-snmp implementation polls for link state change every 60 seconds, that likely explains what you observed. An event based mechanism is supposed to appear in a future release.

Answer Six:  (by Sandiyago)  more reading suggests by using an agent compiled with Event MIB support we may be able to control the polling FREQUENCY:

http://www.net-snmp.org/docs/man/snmpd.conf.html

DisMan Event MIB:
linkUpDownNotifications yes
will
configure the Event MIB tables to monitor the ifTable for network
interfaces being taken up or down,
and triggering a linkUp or
linkDown notification as appropriate.

This is exactly equivalent to the configuration:
notificationEvent linkUpTrap linkUp ifIndex ifAdminStatus ifOperStatus
notificationEvent linkDownTrap linkDown ifIndex ifAdminStatus
ifOperStatus

monitor -r 60 -e linkUpTrap ""Generate linkUp"" ifOperStatus != 2
monitor -r 60 -e linkDownTrap ""Generate linkDown"" ifOperStatus == 2

It is likely using a different -r x may do the trick. But it may not if the linkDown/linkUp traps are hard-coded to a minimum 60 seconds to avoid the overhead of frequent polling.

Answer Seven:  (by TinyTimmy)  I was already using the ""monitor"" lines below with -r value of 2 (two seconds).

 

However, what is useful is to learn that despite what the documentation says in net-snmp about the -r flag controlling the testing interval the fact is that the testing interval is "hard-coded to a minimum 60 seconds".

That means that if one is using net-snmp that the link-up/down traps are really only useful if one doesn't care about things that could occur in less than a minute.

If one is in a security center this means that a bad person could insert a man-in-the-middle box and if the cables are switched quickly that nobody would notice that link-state went down and then came back.

And if one is in a NOC one could miss transient link drops/recovery(indicative of an error condition) unless that condition just happened to occur at the instant net-snmp made its once a minute test.

SilverCreek -- Connecting remote CLI from SilverCreek? Is it possible?

Question:  (by Syed)  Hi All, I am trying to issue " show ip route " to the CISCO or any devices cli prompt.  

Is there any method or API available in silvercreek to send CLI commands using tcl script?  

Please help me if any way to access remote CLI using ip address?

-Thanks,
Syed

Answer One:  (by Sandiyago) Since SilverCreek is a Tcl interpreter so I believe you can use whatever method (telnet, ssh ) available in Tcl language to connect to the remote server. For example, Telnet http://wiki.tcl.tk/684

 

You can consider using expect (http://www.nist.gov/el/msid/expect.cfm) to automate login that requires password, or set up public key authentication to avoid entering password (ssh)..

Answer Two:  (by Syed)  Whether the agent ip and telnet/ssh ip address should be same?

Answer Three: (by Sandiyago)  It may or may not be the same depending on the target that you are trying to log in, right? The IP address of telnet/ssh used in the script should be the same as that you would type in a shell.

Answer Four:  (by Syed)  When i try to execute ssh to the ip where the agent is running , i faced below error.

Please help me how to use "spawn" command?

[ERROR] Remarks: An error occurred during execution 
invalid command name "spawn" 
while executing 
"spawn ssh root@$ip"
(file"./testsuite/private-tests/chTest/testSNMP-TE-TNNL-PE-01.tcl""
line 7)
invoked from within 
"source $testfile"

Answer Five: (by Syed)  I need to execute the expect and spawn commands in silver creek?

 

#!/usr/bin/expect

set ip 172.23.130.134
set user "root"
set pwd
"Welcome123"
spawn ssh root@$ip
expect {
-re ".*Are.*.*yes.*no.*" {
send "yes\r"
expect "password:"
send "$pwd\r"
expect
"#"
}
"password:" {
send "$pwd\r"
expect "#"
}
}

Answer Six:  (by Sandiyago) Spawn is form Expect package, did you install Expect package?

If you are using SilverCreek's Tcl, place the Expect folder under the 'lib' directory. You can see other libraries like "snmptcl", "tkTable" there etc. Alternatively you can place Expect anywhere but update Tcl's "auto_path" so it can be found.

If you are using your own Tcl, then install it as Expect's installation instruction.  

The best approach is to use a standard Tcl, install Expect, and make sure it works then place it in your SilverCreek test.

Answer Seven:  (by Syed)  I have installed expect package in below path:

 

"C:\Tcl\lib\teapot\package\win32-ix86\lib\Expect5.43.2"

From tclsh ,

% puts $auto_path
C:/Tcl/lib/tcl8.5 C:/Tcl/lib
c:/tcl/lib/teapot/package/win32-ix86/lib
c:/tcl/lib/teapot/package/tcl/lib example/example/
%

From Silver creek console , 

Console display active (Tcl8.4.14 / Tk8.4.14)
(SilverCreekMx) 49 % puts $auto_path
{C:/Program Files
(x86)/InterWorkingLabs/SilverCreekMx/lib/tcl8.4} 
Files
(x86)/InterWorkingLabs/SilverCreekMx/bin} {C:/Program Files 
 (x86)/InterWorkingLabs/SilverCreekMx/lib/autoint} {C:/Program
Files
 (x86)/InterWorkingLabs/SilverCreekMx/lib/BWidget-1.4.1}
{C:/Program Files 

(x86)/InterWorkingLabs/SilverCreekMx/lib/compat} {C:/Program
Files 

(x86)/InterWorkingLabs/SilverCreekMx/lib/gdi}{C:/Program
Files 
 (x86)/InterWorkingLabs/SilverCreekMx/lib/guilib}
{C:/Program Files 
 (x86)/InterWorkingLabs/SilverCreekMx/lib/hdc}
{C:/Program Files 

(x86)/InterWorkingLabs/SilverCreekMx/lib/mclistbox-1.02}
{C:/Program 
Files
(x86)/InterWorkingLabs/SilverCreekMx/lib/printer} {C:/Program Files
 (x86)/InterWorkingLabs/SilverCreekMx/lib/scdb} {C:/Program
Files 
 (x86)/InterWorkingLabs/SilverCreekMx/lib/scgui}
{C:/Program Files 

(x86)/InterWorkingLabs/SilverCreekMx/lib/scotty} {C:/Program Files
 (x86)/InterWorkingLabs/SilverCreekMx/lib/sctest} {C:/Program
Files 
 (86)/InterWorkingLabs/SilverCreekMx/lib/snmptcl}
{C:/Program Files 

(x86)/InterWorkingLabs/SilverCreekMx/lib/snmptest} {C:/Program
Files
 (x86)/InterWorkingLabs/SilverCreekMx/lib/sscgui}
{C:/Program Files 

(x86)/InterWorkingLabs/SilverCreekMx/lib/tablelist} {C:/Program
Files 
 (x86)/InterWorkingLabs/SilverCreekMx/lib/TCL8.3}
{C:/Program Files

(x86)/InterWorkingLabs/SilverCreekMx/lib/tcl8.4} {C:/Program
Files 
 (x86)/InterWorkingLabs/SilverCreekMx/lib/timer}
{C:/Program Files 

(x86)/InterWorkingLabs/SilverCreekMx/lib/TK8.3} {C:/Program Files 
 (x86)/InterWorkingLabs/SilverCreekMx/lib/tk8.4} {C:/Program
Files 
 (x86)/InterWorkingLabs/SilverCreekMx/lib/tkTable}
{C:/Program Files 

(x86)/InterWorkingLabs/SilverCreekMx/lib/tools} {C:/Program Files 
 (x86)/InterWorkingLabs/SilverCreekMx/lib/tablelist/scripts},

How i need to add the expect path in to silvercreek auto_path???

Answer Eight:  (by Sandiyago)  In your script ./testsuite/private-tests/chTest/testSNMP-TE-TNNL-PE-01.tcl, try:

 

if {[lsearch $::auto_path
""C:/Tcl/lib/teapot/package/win32-ix86/lib"] == -
1} {
lappend ::auto_path "C:/Tcl/lib/teapot/package/win32-ix86/lib"
}
package require Expect

On Linux, try

if {[lsearch $::auto_path ""C:/usr/lib"] == -1} {
lappend
::auto_path "C:/usr/lib"
}
package require Expect

It should also work if you use "C:/Tcl/lib/teapot/package/win32-ix86/lib/Expect5.43.2", but I don't think that's necessary.

SilverCreek -- How To change the default log path while executing automated testcases in SC?

Question:  (by Syed)  When i executed the testcases , it shows that the log is collected at the below location,

C:/Users/sambalam/AppData/Local/Temp/sctmp-5632-test_SNMP-SLSP-PE- 01-32.log

But is it possible to change the default path?

Thanks in Advance.

-Regards,
Syed

Answer One:  (by Samwa)  go to Tools->Options->Misc: Logging tests results to....

Answer Two:  (by JimLogajan)  Here are two ways to change the default path (the following is based on the operation of the latest release of SilverCreek):

1) Use the GUI menu selection "Tools" -> "Options" to display the Options dialog window. In that window select the "Misc" tab. Near the bottom should be an entry that allows you to select a folder path where the log files are created. Set it to the desired path and click "OK".

2) Set the user environment variable TMP or TEMP so that one of them contains the desired path. The environment variable value will only be used if the GUI options mechanism doesn't set the path.

Setting environment variables on MS Windows varies depending on the version; check Microsoft documentation for guidance. For example, the way such variables are assigned values when using Windows XP is outlined here:  http://support.microsoft.com/kb/310519.

SilverCreek -- Cannot get FlexLM license to work on my new laptop!

Question:  (by TinyTimmy)  I have a new Fedora laptop and when I was installing SilverCreek, my FlexLM hostid is blank. I've done this before and it has never been blank. What do I do?

Answer One:  (by MrFixIt)  Lots of people running into this. FlexLM looks for the MAC address on eth0 and nowhere else! Eth0 is usually the first network interface, but newer versions of Linux do things differently. If you go to the directory where the devices are mapped -- could be /etc/config or /etc/iftab or /etc/udev and rename eth1 to eth0, then it should work.

Answer Two:  (by Jim Logajan)  The following is probably the cause:

Flexlm goes looking for the MAC address on the Ethernet interface named "eth0" and if it doesn't find it, it returns an empty or blank hostid. Most likely your only Ethernet interface was assigned the name "eth1" rather than "eth0".

One way you may be able to rename the interface from "eth1" to "eth0" is to use the Linux "Network" Administration GUI tool (you'll need the root password). In the window that appears you would select on the "Hardware" tab to display a dialog that shows all the interfaces. Select the row with the eth1 device and click on the Edit button. In the dialog box that appears you should see a field that allows you to rename interface to eth0. Just follow through on OKing and saving as indicated. A reboot may not be needed, but probably should be done to insure the change is persistent.

SilverCreek -- Is there a provision to reboot an agent automatically?

Question:  (by Maverick)  If YES, then please suggest how it is done? Answer One:  (by Sandiyago)  This depends on whether the device has implemented a MIB that contains a writable object you can set to cause the agent to reboot. For example, cable module must have DOCS-CABLE-DEVICE-MIB implemented. The DOCS-
CABLE-DEVICE-MIB defines an object:

docsDevResetNow OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-write
STATUS current
DESCRIPTION
?Setting this object to true(1) causes the device to reset.
Reading this object always returns false(2).?
::= { docsDevBase
3 }

So in SilverCreek, you can do a simple SET to reboot the agent automatically snmptcl::snmpset DOCS-CABLE-DEVICE-MIB:docsDevResetNow.0 1

Answer Two:  (by Maverick)  Thanks!  

But can I add the same in the Test-> Advanced Configurations: SNMPv3-USM-MIB-> Reboot

i.e. snmptcl::snmpset DOCS-CABLE-DEVICE-MIB:docsDevResetNow.0 1
or just the integer value '1'?

Answer Three:  (by PumpkinJason)  yes, I used 
snmptcl::snmpset DOCS-CABLE-DEVICE-MIB:docsDevResetNow.0 1

SilverCreek -- MIB-II Tests

Question:  (by Bob Ciulla) Hi,I'm trying to test two SNMP-MIBII attributes from RFC-3418:
snmpSilentDrops and snmpProxyDrops.

I'm using SilverCreek M3 Build 2011.111228 and while the documentation states it supports testing RFC 3428; I do not see specific test cases for the attributes above.

Does anyone know if there are test cases written for these MIB instances?
Thanks in Advance

Answer:  (by PumpkinJason)  SilverCreek test2.2.5.2 and test3.2.5.2 check snmpSilentDrops counter. As for snmpProxyDrops counter it is impossible for SilverCreek to trigger it since SilverCreek has no idea if there is a proxy, and when/how the agent under test will deem "the transmission of the (possibly translated) message to a proxy target failed in a manner (other than a time-out) such that no Response Class PDU (such as a Response-PDU) could be returned."

SilverCreek -- How to see the executed script log?

Question:  (by Syed)  When i executed the testcases , it shows that the log is collected at the below location,

C:/Users/sambalam/AppData/Local/Temp/sctmp-5632-test_SNMP-SLSP-PE- 01-32.log

but when i tried to enter in the path "C:/Users/sambalam/", i dint see any folder named "AppData"

please help me see the collected logs...

Thanks in Advance..

-Regards
Syed

 

Answer:  (by JimLogajan)  On Windows 7, not all folders are made visible by default, which may explain your problem. A bit of web searching yielded the following web site which contains some information on how to change the folder options so that hidden folders will appear:

http://www.sevenforums.com/general-discussion/197219- missing-users-folder-explorer.html

Hopefully that will guide you?

SilverCreek -- How to get the argument values when the agent responded properly to the operation?

Question:  (by Syed)  Hi all,  

SNMP Request Commands Returns: 0 If the agent responded properly to the operation , 1 If the agent did not respond properly to the operation. How to confirm this action?

Will it be possible to print that value?

For ex:

snmptcl::snmpset mplsTunnelRowStatus.$mplsTunnelIndex 7
-context
$snmptcl(agent)

Here i am setting the invalid rowstatus value=7 , agent should return 1 due to error.  I want that value to be printed? Is it possible?

Answer One:  (by PumpkinJason)  You would want to use the option 'rvbinds' as follows:

(SilverCreekMx) 19 % snmptcl::snmpset sysDescr.0 ""Asdad""
-rvbinds rv
1
(SilverCreekMx) 20 % puts $rv
{1.3.6.1.2.1.1.1.0 SNMPv2-TC:DisplayString Asdad}

if the set fails, you can also get the returned error status in '-restatus' option

(SilverCreekMx) 21 % snmptcl::snmpset sysDescr.0 "Asdad" -rvbinds
rv -
restatus re 
1
(SilverCreekMx) 22 % puts
$re 
notWritable

Answer Two:  (by Syed)  Here $rv is printing entire OBJECT ({1.3.6.1.2.1.1.1.0 SNMPv2-TC:DisplayString Asdad) but i need to catch "1" ? 

please let me know if any other option is available?

Answer Three:  (by PumpkinJason)  couldn't you just do

set r [snmptcl::snmpset sysDescr.0 ""Asdad"" -rvbinds rv]
puts $r.

SilverCreek -- How to save the output of a snmptcl::snmpgetcmd to a variable for further usage?

Question:  (by Syed)  My requirement is to get the below index value and need to save in the variable But when i did through SC GUI , it gave the below snippet.

snmptcl::snmpget -vbinds mplsTunnelIndexNextIndex.1 
-rvbinds res -restatus estatus -expectstatus noError \
-expectvalue 2 -reindex eindex -octetstringformat 1 -comments comm\
-context $snmptcl(agent)

but when i try to edit the above script (shown below) and re-run it failed. Also help me to execute in CONSOLE too...
#get mplsTunnelIndexNextIndex.1

set mplsTunnelIndex [snmptcl::snmpget -vbinds
mplsTunnelIndexNextIndex.1 \
-rvbinds res -restatus estatus -expectstatus noError \
-reindex eindex -octetstringformat 1 -comments comm\
-context $snmptcl(agent)]
puts $mplsTunnelIndex

if { $comm != "" } {
append results ""\nCOMMENTS: GET on
mplsTunnelIndexNextIndex.1; 
Expected value:
$mplsTunnelIndex \n$comm"
set type "failed"
} else {
append results "\n \nGET on mplsTunnelIndexNextIndex.1; Expected
value:
$mplsTunnelIndex \n "
set type "passed"
}
::snmptools::scriptcmdtool::writeMessage $type $results
set results

Answer One:  (by Sandiyago)  When you generate a command using SC GUI, the generated command always uses the default agent context "handle", i.e., the currently connected agent: $snmptcl(agent)

 

set mplsTunnelIndex [snmptcl::snmpget -vbinds
mplsTunnelIndexNextIndex.1 \
-rvbinds res -restatus estatus -expectstatus noError \
-reindex eindex -octetstringformat 1 -comments comm\
-context $snmptcl(agent)]
>puts $mplsTunnelIndex

This won't work. The returned value is only a status indicating whether the request succeeded or failed. It is not the value of the variable.

The value is contained in the variable 'res' given in the option ""-rvbinds res"". It is a list.

Try:

puts $res

I read SC developer guide, it is often better to just write your own command. In this case I think you can simply do

snmptcl::snmpget mplsTunnelIndexNextIndex.1 value
-context
$snmptcl(agent)
puts $value

Answer Two:  (by Syed)  Thanks a lot. But still i have the below queries:

1. Similar to snmpget , please let me know how to perform "snmpset"

snmptcl::snmpset mplsTunnelRowstatus.1 5 -context $snmptcl(agent)
puts $value

2. When i try to use the SC console , it is not showing for "snmpget", "snmpset".

Please let me know how the below command should be used in console.

Answer Three:  (by Sandiyago)  

1. snmptcl::snmpset mplsTunnelRowstatus.1 5 -context $snmptcl(agent)

That should work. It should set mplsTunnelRowstatus.1 to value 5. But in order to create a row, you usually need to set other columnar objects in the same 'set' operation.

2. didn't see the command you mentioned in your second query so can't help..

Answer Four:  (by Syed)  When i tried "snmptcl" or "snmpget" help in the SC console , i dint get any help commands related to it.

(SilverCreekMx) 46 % help snmpget
This command is not supported by the help utility. Try "snmpget /?".
SilverCreekMx) 47 % snmpget ?
wrong # args: should be "snmpget test oidlist estat eind vbs args"
(SilverCreekMx) 48 % snmpget /?
wrong # args: should be "snmpget test oidlist estat eind vbs args"
(SilverCreekMx) 49 % snmpget help
wrong # args: should be "snmpget test oidlist estat eind vbs args"

How to see the usage of commands?"

Answer Five:  (by Sandiyago)  The command reference is in SilverCreek developer guide. I found it is very very useful since it has lots of examples.

SilverCreek -- How to send a snmp get command?

Question: (by Sandiyago)  Hi, I need to send SNMP get commands in one of our automated test scripts. Can anyone quickly tell me how can I do that?

We have been using Net-SNMP command line utilities but would like to use SilverCreek's Tcl command since our test scripts are all written in Tcl. It is ""painful"" to call SNMP shell commands in our Tcl scripts.

Thanks in advance!"

Answer One: (by PumpkinJason)  The following simple commands show you how this can be done:

set ctx [snmptcl::context::create -address 192.168.1.1 \
-version SNMPv1 -rcomm public ]
 snmptcl::snmpget sysDescr.0
value -context $ctx
 puts $value

Hope this helps!

Answer Two:  (by Syed)

1)  Actually, what the below step will do?

set ctx [snmptcl::context::create -address 192.168.1.1 \
-version SNMPv1 -rcomm public ]

2) My requirement is to get the below index value and need to save in the variable But when i did through SC GUI , it gave the below snippet.

snmptcl::snmpget -vbinds mplsTunnelIndexNextIndex.1 \
-rvbinds res -restatus estatus -expectstatus noError \
-expectvalue 2 -reindex eindex -octetstringformat 1 -comments
comm\
-context $snmptcl(agent)

but when i try to edit the above script(shown below) and re-run it failed. Also help me to execute in CONSOLE too...

#get mplsTunnelIndexNextIndex.1
 set mplsTunnelIndex
[snmptcl::snmpget -vbinds mplsTunnelIndexNextIndex.1 \
-rvbinds
res -restatus estatus -expectstatus noError \
-reindex eindex
-octetstringformat 1 -comments comm\
-context $snmptcl(agent)]
puts $mplsTunnelIndex
if { $comm != """" } { 
append results "\nCOMMENTS: GET
on mplsTunnelIndexNextIndex.1; 
Expected value:
$mplsTunnelIndex \n$comm"
set type "failed"
} else
{ 
append results "\n \nGET on mplsTunnelIndexNextIndex.1;
Expected value: 
$mplsTunnelIndex \n "
set type
"passed"
}
::snmptools::scriptcmdtool::writeMessage $type $results
set
results""

Answer Three:  (by Sandiyago)  

"set ctx [snmptcl::context::create -address 192.168.1.1 \
-version SNMPv1 -rcomm public ]

This creates an agent context "handle". The context handle "encapsulate" agent IP address, community string etc.

Then later you can use the handle like

snmptcl::snmpget sysDescr.0 value -context $ctx

Answer Four:  (by Sandiyago)  When you generate a command using SC GUI, the generated command always uses the default agent context "handle", i.e., the currently connected agent: $snmptcl(agent)

SilverCreek -- Slow down testing?

Question:  (by PumpkinJason)  Hi All, I have a very "slow" agent--apparently it can't keep up with the test packets sent by SilverCreek. Can I slow down the speed at which the test packets are sent? Is this even possible?  Thanks!

Answer One:  (by Sandiyago)   Yes you can do that. You Can Test->Fine-tune Testing Options: "Insert a delay between sending test packets...". We once had the same problem. But since our agent has been optimized so that is no longer an issue for us.

Hope this helps!

Answer Two:  (by PumpkinJason)  Thanks!

SilverCreek -- Disable sysUpTime checking?

Question:  (by Sandiyago)  Hi, All my tests failed in checking sysUpTime value since our agent did not implement sysUpTime object. Well this makes it impossible to run any meaningful tests? Is there a way I can tell SilverCreek not to check sysUpTime while running tests?  Thanks!

Answer One:  (by illnifan)  Select menu Tools->Options, click on "Test" Tab, and uncheck the check-box "Check System Reboot during each test ....". This should do what you want.

Answer Two:  (by PumpkinJason)  That worked for me! Thanks!

Answer Three:  (by Maverick)  Thanks for the solution, I was also struggling with this. It is very useful.

SilverCreek -- Testing aborted unexpectedly after a few failures?

Question:  (by Sandiyago)  Hi All,  I am new to SilverCreek. I noticed that, when I run tests, they always exit after a certain number of failures have been detected. How do I force a test not to exit until it finishes? I want to get all failures/errors report in a single test run.  Thanks in advance!

Answer One:  (by PumpkinJason)  You need to configure Test->Fine-tune Testing Options: Number of Error allowed before applicable tests stop... The default is 10, set it to 0.

Silvercreek - Change SNMP Timeout Setting

Question:  (by Sandiyago)  I feel this should be a simple question. But I am new to SilverCreek so... Can somebody quickly tell me how can I change the timeout settings?  Thanks a lot!

Answer One:  (by PumpkinJason)  You can change timeout setting when you connect to your device. There is an optional option "timeout and retry settings".  I think that is what you are looking for.  Cheers

Answer Two:  (by Sandiyago)  yes. that's what I was looking for...Thanks!

SilverCreek -- Execute a tcl script from DOS window?

Question:  (by PumpkinJason) Hi all, Can anyone quickly tell me how to run a Tcl script from the DOS command line? I have batch_run_silvecreek_tests.tcl script from a colleague and I need to run it, so now how should I do it?  Thanks in Advance.

Answer:  (by illnifan)  tclsh84.exe your_script.tcl

Hope this helps!