Cisco - EEM Scripts Examples (TSHOOT)

EEM is a very useful tool to troubleshoot occasional, sporadic CPU spikes that are short-lived and difficult to troubleshoot manually with the command line interface. This is an example of CPU spikes:

Switch#show process cpu history
<snip>
    11111822511   11 111277711111 124111  11 1211111112161116
    143342171209994090111878458239607111981270283361362429475
100
 90
 80      *               ***
 70      *               ***                                *
 60      *               ***                            *   *
 50      *  *            ***        *                   *   *
 40      *  *            ***        *                   *   *
 30      * **            ***        *                   *   *
 20      ****           **** **   ***         **  *  ** ** **
 10 *********************************************************
   0....5....1....1....2....2....3....3....4....4....5....5....6....6....7.
             0    5    0    5    0    5    0    5    0    5    0    5    0
                   CPU% per hour (last 72 hours)
                  * = maximum CPU%   # = average CPU%

This section includes several examples of the use of EEM scripts to monitor CPU utilization. Catalyst 2960 and 3750 switches allow EEM to use non-volatile RAM (NVRAM); Catalyst 4500 switches allow EEM to write to bootflash; and Catalyst 6500 switches allow EEM to use disk0 and sup-bootdisk.

Email Alerts

This script emails an alert when CPU utilization goes above 50 percent. The body of the email is the output of theshow process cpu sorted command.

event manager applet highcpu
  event snmp oid 1.3.6.1.4.1.9.9.109.1.1.1.1.3.1 get-type exact entry-op ge 
  entry-val 50 poll-interval 0.5
  action 1.0 cli command "enable"
  action 2.0 cli command "show proc cpu sorted"
  action 3.0 mail server "192.168.1.1" to "user-to@domain.com" from "user-from@domain.com" 
  subject "High CPU Alert" body "$_cli_result"

The definitions of italicized variables are:

highcpu - name of the event manager applet/script

1.3.6.1.4.1.9.9.109.1.1.1.1.3.1 - Object identifier (OID) for polling the total CPU utilization of the route processor (RP)

50 - CPU utilization that triggers the script
poll-interval 0.5 - Frequency (every 0.5 seconds) the script monitors the CPU

192.169.1.1 - IP of the mail server

Append Output to Local File

This script appends required outputs to a file in the local file system. Replace file system with the appropriate file system on the switch.

event manager scheduler script thread class default number 1 
event manager applet High_CPU
event snmp oid 1.3.6.1.4.1.9.9.109.1.1.1.1.3.1 get-type exact entry-op ge  
    entry-val 50 poll-interval 0.5
  action 0.0 syslog msg "High CPU DETECTED. Please wait - logging Information  
    to file system:high_cpu.txt"
  action 0.1 cli command "enable"
  action 0.2 cli command "show clock | append file system:high_cpu.txt"
  action 1.2 cli command "term length 0"
  action 1.3 cli command "show process cpu sorted | append file system:high_cpu.txt"
  action 1.4 cli command "show log | append file system:high_cpu.txt"
  action 1.5 cli command "show interfaces | append file system:high_cpu.txt"
  action 1.6 cli command "term length 24"

Append Output to Local File and Remove Script

This script appends the output of the show process cpu sorted command to a file in the local file system, then removes itself once completed. Replace file system with the appropriate file system on the switch.

event manager scheduler script thread class default number 1 
event manager applet High_CPU
event snmp oid 1.3.6.1.4.1.9.9.109.1.1.1.1.3.1 get-type exact entry-op gt 
    entry-val 50 poll-interval 0.5
  action 0.0 syslog msg "High CPU DETECTED. Please wait - logging Information  
    to flash:high_cpu.txt"
  action 0.1 cli command "enable"
  action 0.2 cli command "term exec prompt timestamp"
  action 1.3 cli command "show process cpu sorted | append file system:high_cpu.txt"
  action 1.4 cli command "show process cpu sorted | append file system:high_cpu.txt"
  action 1.4 cli command "show process cpu sorted | append file system:high_cpu.txt"
  action 5.1 syslog msg "Finished logging information to file system:high_cpu.txt..."
  action 5.1 syslog msg "Self-removing applet from configuration..."
  action 5.2 cli command "term no exec prompt timestamp"
  action 9.1 cli command "configure terminal"
  action 9.2 cli command "no event manager applet High_CPU"
  action 9.3 cli command "end"

Collect Output and Write to Local File

This script uses a syslog-based trigger in order to run and collect required outputs and write those outputs to the local file system. Replace file system with the appropriate file system on the switch.

process cpu threshold type total rising 70 interval 15 
event manager applet DETECT_CPU
event syslog pattern ".*SYS-1-CPURISINGTHRESHOLD.*" 
  action 1 cli command "en" 
  action 2 cli command "show clock | append file system:cpuinfo" 
  action 3 cli command "show proc cpu sort | append file system:cpuinfo" 
  action 4 cli command "show line | append file system:cpuinfo"

Monitor CPU Utilization on Modular IOS

The Cisco EEM can also be used to monitor CPU utilization on modular IOS. Because of the differences in how the CPU is monitored on modular IOS, you can use the Simple Network Management Protocol (SNMP) OID (1.3.6.1.4.1.9.9.109.1.1.1.1.3.1) in order to check CPU utilization by the IOS base process.

This script uses the OID as a trigger and writes required outputs to the local file system. Replace file system with the appropriate file system on the switch.

event manager scheduler script thread class default number 1
event manager applet High_CPU
event snmp oid 1.3.6.1.4.1.9.9.109.1.1.1.1.10.1  get-type exact entry-op ge  
    entry-val 50 poll-interval 0.5 
  action 0.0 syslog msg "High CPU DETECTED. Please wait - logging Information  
    to file system:high_cpu.txt"
  action 0.1 cli command "enable"
  action 0.2 cli command "show clock | append file system:high_cpu.txt"
  action 1.2 cli command "term length 0"
  action 1.3 cli command "show process cpu sorted | append file system:high_cpu.txt"
  action 1.4 cli command "show log | append file system:high_cpu.txt"
  action 1.5 cli command "show interfaces | append file system:high_cpu.txt"
  action 1.6 cli command "term length 24"

Remove Script

Enter this command in order to remove an EEM script:

Switch(config)#no event manager applet applet 

Based On: http://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/116141-trouble-eem-scripts-00.html
Contributed by Cisco Engineers: Shashank Singh and Saurav Lahiri

Linux - PPTP VPN Server (via GUI on Ubuntu)

 

How to Setup a “Split Tunnel” VPN (PPTP) Client on Ubuntu 10.04

Sometimes you need to use a VPN connection to grant access to remote network resources and for that you use a VPN, but if you don’t want all of your client traffic to go through the VPN link, you’ll need to setup your VPN to connect in a “split tunnel” mode. Here’s how to do it on Ubuntu.

Note: make sure that you’ve read our article covering how to setup a VPN server for Debian-based Linux, which also covers configuring the Windows client.

 

Split what the what now?

The “split tunnel” term refers to the fact that the VPN client creates a “tunnel” from the client all the way to the server for “private” communication.

Traditionally the VPN connection is set up to create “the tunnel” and once it is up all the client’s communication is routed through that “tunnel”. this was good back in the day when the VPN connection had a couple of goals that overlapped and complimented each other:

• The connection was meant to grant access for the road warrior from anywhere.
• All of  the client’s connections need to be secured by means of  going through the corporate firewall.
• The client computer must not be able to connect a potentially malicious network with the corporate network.

The way the VPN connection of the time achieved this goal, was to set the “default gateway” or “route” of the client machine to the corporate VPN server.

• This method, while affective for the above goals has several disadvantages, espeshelly if you are implementing the VPN connection only for the “grant access” point:
• It will slow down the entire surfing experience of the client computer to the speed of the VPN server’s upload speed, which is usually slow.
• It will disable access to local resources like other computers in the local network unless they are all connected to the VPN, and even then the access will be slowed down because it has to go all the way to the internet and come back.

To overcome these shortcomings we will create a regular VPN dialer with one note worthy exception, that we will set the system to NOT use it as the “Default Gateway” or “route” when connected.

Doing this will make it so that the client will use the “VPN tunnel” only for the resources behind the VPN server and will access the internet normally for everything else.

 

Let’s get cracking

The first step is to get into “Network connections” and then “Configure VPN”.

One way you can do this is by clicking the desktop icon for networking as shown in the picture.

Another way is to go to “System” > “Preferences” > “Network Connections”.

Once your on the “VPN” tab in the “Network connections” configurations window, click “Add”.

On the next window we only need to click “Create”, as the default connection type of PPTP is what we want to use.

In the next window give your dialer a name, fill in the gateway with your servers DNS-name or IP address as seen from the internet and fill in the user credentials.

If you have used the “Setting up a VPN (PPTP) server on Debian” guide for the server setup or you are using this client for a DD-WRT PPTP server setup, you also need to enable the MPPE encryption options for authentication.

Click on “Advanced”.

On the “Advanced Options” window check the first checkbox for the MPPE option, then the second checkbox to allow stateful encryption and click “OK”.

Back on the main window, click the “IPv4 Settings” tab.

On the routes configuration window check the checkbox of “Use this connection only for resources on its network”.

Activate the VPN connection client by clicking on the “Network connections” icon and selecting it.

That’s it, you can now access the resources on the VPN servers side as if you were on the same network while not sacrificing your download speed in the process…

 

Taken From: http://www.howtogeek.com/51340/setting-up-a-split-tunnel-vpn-pptp-client-on-ubuntu-10-04/

Linux - PPTP VPN Server & Win XP/7 Client

 

How to Setup a VPN (PPTP) Server on Debian Linux
(also tested on the Raspberry Pi on Raspbian)

VPN-ing into your server will allow you to connect to every possible service running on it, as if you were sitting next to it on the same network, without individually forwarding every port combination for every service you would like to access remotely.

Using a VPN connection also has the upshot of, if desired, granting access to other computers on the network as if you where in it locally from anywhere across the internet.

While not the most secure of the VPN solutions out there, PPTP is by far the simplest to install, configure and connect to from any modern system and from windows specifically as the client is a part of the OS since the XP days and you don’t need to mess with certificates (like with L2TP+IPsec or SSL VPNs) on both sides of the connection.

Did i get you interested? then let’s go :)

 

Preface

• You will need to forward port 1723 and the GRE protocol (47) from the internet to the server to enable the connection (not covered here).
• You will see me use VIM as the editor program, this is just because I’m used to it… you may use any other editor that you’d like.~

 

Server Setup

Install the pptp server package:
    sudo aptitude install pptpd

Edit the “/etc/pptpd.conf” configuration file:
    sudo vim /etc/pptpd.conf

Add to it:
    option /etc/ppp/pptpd-options
    localip 192.168.1.5
    remoteip 192.168.1.234-238,192.168.1.245

Where the “localip” is the address of the server, and the remoteip are the addresses that will be handed out to the clients, it is up to you to adjust these for your network’s requirements.

Edit the “/etc/ppp/pptpd-options” configuration file:
    sudo vim /etc/ppp/pptpd-options

Append to the end of the file, the following directives:
    ms-dns 192.168.1.1
    nobsdcomp
    noipx
    mtu 1490
    mru 1490

here we are assuming that we are editing the pptpd default options config and adding to it, but if for some reason you start with a black “pptpd-options”, you will need to enter those defaults (based on a “pptpd-options” on Raspberry Pi Runing Raspbian):

name pptpd

# BSD licensed ppp-2.4.2 upstream
# with MPPE only
refuse-pap
refuse-chap
refuse-mschap

# Require the peer to authenticate
# itself using MS-CHAPv2
require-mschap-v2

# Require MPPE 128-bit encryption
require-mppe-128

# Making the peer appear to other
# systems to be on the local ethernet
proxyarp

# Debian: do not replace the default route
# with this you get split tunelling
nodefaultroute

# Create a UUCP-style lock file for
# the pseudo-tty to ensure exclusive
lock

# Disable Van Jacobson compression
novj
nobsdcomp

# Turn off logging to stderr
nologfd

to get more detail on each item check a default “pptpd-options” file it’s has quite some detail on each item.

Where the IP used for the ms-dns directive is the DNS server for the local network your client will be connecting to and, again, it is your responsibility to adjust this to your network’s configuration.

Edit the chap secrets file:
    sudo vim /etc/ppp/chap-secrets

Add to it the authentication credentials for a user’s connection, in the following syntax:
    username <TAB> * <TAB> users-password <TAB> *

Restart the connection’s daemon for the settings to take affect:
    sudo /etc/init.d/pptpd restart

If you don’t want to grant yourself access to anything beyond the server, then you’re done on the server side.

 

Enable Forwarding (optional)

While this step is optional and could be viewed as a security risk for the extremely paranoid, it is my opinion that not doing it defeats the purpose of even having a VPN connection into your network.

By enabling forwarding we make the entire network available to us when we connect and not just the VPN server itself. Doing so allows the connecting client to “jump” through the VPN server, to all other devices on the network.

To achieve this we will be flipping the switch on the “forwarding” parameter of the system.

Edit the “sysctl” file:
    sudo vim /etc/sysctl.conf

Find the “net.ipv4.ip_forward” line and change the parameter from 0 (disabled) to 1 (enabled):
    net.ipv4.ip_forward=1

You can either restart the system or issue this command for the setting to take affect:
   sudo sysctl -p

With forwarding enabled, all the server side settings are prepared.

We recommend using a “Split Tunnel” connection mode for the VPN client.

A more in depth explanation about the recommended “Split Tunnel” mode, as well as instructions for Ubuntu Linux users can be found in the “Setting up a “Split Tunnel” VPN (PPTP) Client on Ubuntu 10.04” guide.

For windows users, follow the guides below to create the VPN client on your system.

 

 

PPTP VPN Dialer Setup on XP (split tunnel)

We will create a regular VPN dialer with one note worthy exception, that we will set the system to NOT use it as the “Default Gateway” when connected.

Skipping this step will limit the connecting computer’s surfing speed to the VPN server’s upload speed (usually slow) because all of it’s traffic would be routed through the VPN connection and that’s not what we want.

We need to start the connection wizard, so we will go to control panel.

Go to “Start” and then “Control Panel”.

*If your system is setup with the “Classic Start Menu” you need to just point on the “Control Panel” icon and then select “Network Connections”.

In “Control Panel” double click “Network Connections”.

Double click “New Connection wizard”.

In the “New Connection wizard” welcome screen click “Next”.

Select the “Connect to the network at my workspace” option and then “Next”.

Select the “Virtual Private Network connection” option and then “Next”.

Give a name to the VPN connection.

Type in the name of your VPN servers DNS-name or IP address as seen from the Internet.

Optionally You may choose to “Add a shortcut to the desktop” and “Finish”.

Now comes the tricky part, it is vitally important you do NOT try to connect now and go into the dialer’s “Properties”.

Go to the networking tab and change the “Type of VPN” to “PPTP VPN” as shown in the picture below (this is optional but will shorten the time it takes to connect) then go into “Properties”.

On the next window go into “Advance” without changing anything else.

On the next window, uncheck the “Use default gateway on remote network” option.

Now enter the connection’s credentials as you set them on the server and connect.

That’s it, you should now be able to access all the computers on your network from the XP client… Enjoy.

 

 

PPTP VPN Dialer Setup on Win7 (split tunnel)

We will create a regular VPN dialer with one note worthy exception, that we will set the system to NOT use it as the “Default Gateway” when connected.

Skipping this step will limit the connecting computer’s surfing speed to the VPN server’s upload speed (usually slow) because all of it’s traffic would be routed through the VPN connection and that’s not what we want.

We need to start the connection wizard, so we will go to the “Network and Sharing Center”.

Click the network icon in the system tray and then “Open Network and Sharing Center”

In the Network center click on “Set up a new connection or network”.

Select “Connect to a workplace” and then “Next”.

Click on the first option of “Use my Internet connection (VPN)”.

Set the address of your VPN server as seen from the internet either by DNS-name or IP.

Even though it won’t connect now because we stil need to go into the dialer’s properties, Set the username and password and hit connect.

After the connection will fails to connect (that’s normal), click on “Set up the connection anyway”.

Back in the “Network Center”, click on “Change adapter settings”.

Find the dialer we have just created, right click it and select “Properties”.

While its optional, for a faster connecting dialer, set the “type” of VPN to PPTP under “the “Security” tab.

Go to the “Networking” tab, select the IPv4 protocol and go into it’s properties.

In the next window, click “Advance” without changing anything else.

On the next window, uncheck the “Use default gateway on remote network” option.

Now enter the connection’s credentials as you set them on the server and connect.

That’s it, you should now be able to access all the computers on your network from the win7 client.

Note: Be sure and read our guide to setting up a VPN client for Ubuntu Linux.

Based On; http://www.howtogeek.com/51237/setting-up-a-vpn-pptp-server-on-debian/

Windows – PPTP VPN Server (+IOS Client +Port Forward)

Here we are going to show you how to set up a Home VPN by using a user PC running windows, so that you can access you home network form almost every device. 

 

 

VPN Server (Windows – User Edition)

The configuration is identical in Windows 7/8/10 (maybe on XP to)

To create the VPN Server you should go to Control Panel > Network and Internet and then Network Connections .

Ther you should press the ALT key so that the options bar appears, next you should go to File > New Incoming Connection

Select or add the users that can access the VPN

(Optional) In case that you want to define the addresses to give to the remote machines you should click on Properties

Now you have a PPTP VPN Server that receives the tunnels and forwards the traffic to the Lan, where it’s connected.

 

Port Forwarding

On your home router you need to forward PPTP trafic to your internal PPTP VPN Server.

Your need to forward:

• PPTP Port 1723: Router Public IP ==> Internal PPTP Server
• GRE Protocol (Protocol 47) : Router Public IP ==> Internal PPTP Server

 

VPN Client

Almost every system has a PPTP client already installed (IPhone / Android / Windows / Linux)

For the IPhone just do:

• Description / Descrição: Brief description of the connection
• Server / Servidor: Router Public IP / Name (DynDNS like no-ip)
• Account / Conta: User Name
• Password / Palavra-passe: Password
• 

for the other systems the configuration is also pretty straight forward

Based on:

• http://pplware.sapo.pt/microsoft/windows/tutorial-aceda-remotamente-a-sua-rede-meo-de-casa-por-vpn/