Requirements: net-snmp, net-snmp-utils, mrtg, lighttpd

mrtg : Multi Router Traffic Grapher

net-snmp and net-snmp-utils : SNMP (Simple Network Management Protocol) is a protocol used for network management. The NET-SNMP project includes various SNMP tools. net-snmp package contains the snmpd and snmptrapd daemons, documentation, etc. You also want to install the net-snmp-utils package, which contains NET-SNMP utilities.

Install the packages

# yum install mrtg net-snmp net-snmp-utils

Configure snmpd.conf

# cp /etc/snmpd/snmpd.conf /etc/snmpd/snmpd.conf.factory-default

# vi /etc/snmpd/snmpd.conf

Comment out the contents, append: (http://www.sofee.cn/blog/2006/10/21/49/)

##############################################################
# Added by Justin
## sec.name source community
com2sec local   localhost       public
com2sec lan     192.168.1.0/24  public

## group.name sec.model sec.name
group   MyRWGroup       v1      local
group   MyRWGroup       v2c     local
group   MyRWGroup       usm     local
group   MyROGroup       v1      lan
group   MyROGroup       v2c     lan
group   MyROGroup       usm     lan

view all    included  .1                               80
#view mib2   included  .iso.org.dod.internet.mgmt.mib-2 fc

## context sec.model sec.level prefix read write notif
access MyROGroup ""      any       noauth    exact      all    none   none
access MyRWGroup ""      any       noauth    exact      all    all    all
rocommunity  public
disk / 100000
disk /mnt/share 500000
##############################################################

Save and close the file

# chkconfig snmpd on
# service snmpd restart

Make sure you see interface IP, by running the following command:

# snmpwalk -v 1 -c public localhost IP-MIB::ipAdEntIfIndex

Sample Outputs:

IP-MIB::ipAdEntIfIndex.123.xx.yy.zzz = INTEGER: 2
IP-MIB::ipAdEntIfIndex.127.0.0.1 = INTEGER: 1

Configure MRTG

# vi /etc/mrtg/mrtg.cfg

OR

# /usr/bin/cfgmaker –global ‘WorkDir: /var/www/mrtg’ –output /etc/mrtg/mrtg.cfg public@127.0.0.1

Create the html file

# indexmaker --output=/var/www/mrtg/index.html /etc/mrtg/mrtg.cfg

Configure Lightttpd

# vi /etc/lighttpd/lighttpd.conf

Add a new alias:

alias.url + ( "/mrtg" => "/var/www/mrtg/www" )

or Append the alias:

alias.url += ( "/mrtg" => "/var/www/mrtg/www" )

Please read the followings for detailed tutorials or documentation.

English Tutorials:

http://www.cyberciti.biz/faq/centos-fedora-linux-multi-router-traffic-grapher-tutorial/

Chinese Tutorials:

http://lincf0315.blogspot.com/2007/04/mrtgcentos.html

http://forum.icst.org.tw/phpbb/viewtopic.php?t=14871

http://www.lslnet.com/linux/f/docs1/i05/big5132597.htm

http://www.sofee.cn/blog/2006/10/21/49/

Official documentation:

http://oss.oetiker.ch/mrtg/doc/mrtg-reference.en.html

http://oss.oetiker.ch/mrtg/doc/mrtg-unix-guide.en.html

MRTG Implementation Manual

By Florin Prunoiu

Pada kesempatan kali ini saya sebagai Newbie yang baru belajar akan mencoba membahas sedikit mengenai masaalah Sistem Keamanan Jaringan ala pemula… jadi buat para mast3r atau yang ngerasa mast3r, dilarang membaca tulisan ini apalagi mengkritik wkwkwkwkwk sekali lagi ilmu untuk berbagi, Meskipun Saya sendiri belum pernah menjadi sysadmin berkelas berat seperti sysadmin pada google atau facebook :p atau sysadmin kayak perusahan telekomunikasi seperti telkomsel dll, jangankan telkomsel sysadmin di warnet aja belum… wkwkwkkwkwk tapi setidaknya saya pernah menjadi anggota jaringan DBS dan TIANSI wkwkwkwkwk maksud saya jaringan lokal di rumah saya sendiri…!
oke dari pada banyak bacot, langsung aja… maksud saya membuat tulisan ini karena terilhami kisah chatting dengan salah satu anggota grup ini, yang menyinggung masalah sysadmin dan keamanan para administrator jaringan kecil seperti admin pada warnet maupun admin warkop (hot spot area)… nah karena kita membicarakan masalah keamanan jaringan ada baiknya kita menengok beberapa tulisan, seperti “menyedot bandwith dengan mozilla firefox” tapi sebenarnya bukan menyedot bandwith tapi lebih tepatnya menggunakan fasilitas proxy yang berganti-ganti agar sealu mendapatkan jatah sebagai user baru dan bekerja menggunakan fasilitas proxy extension pada mozilla (switch proxy) kemudian tools yang bernama “netcut”, wah… pasti teman-teman tidak asing lagi dengan kedua barang diatas, tapi saat ini kita bukan membicarakan masalah menyerang (“itu karena saya tidak tau wkwkwkwkwkwk”) tapi terlebih beberapa saran kepada para admin jaringan kecil agar terhindar dari dampak buruk sedot bandwith ala mozilla dan ARP Poisoning ala netcut (jiah… gaya bicara saya kayak orang professional ajah… ) langsung aja download MRTG di http://oss.oetiker.ch/mrtg/pub/?M=D untuk memonitor bandwith terus download anti netcut di http://tools4free.com, MRTG “adalah singkatan dari Multi Router Traffic Grapher, merupakan tools yang berfungsi untuk mengamati besar trafik yang melewati suatu interface tertentu dimana yang bekerja ialah protokol SNMP, kemudian dari data yang diperoleh tersebut, akan dibuat suatu grafik sehingga mudah diamati oleh seorang admin jaringan” (copy paste red;) jadi agar tool ini berfungsi aktifkan dulu fitur SNMP dan telah terinstall Apache web server di OS anda. Kemudian Anti Netcut digunakan untuk mengidentifikasi pengguna netcut (tools untuk melakukan ARP Poisonoing, sehingga computer clint bisa setara sysadmin dalam sebuah workgroup). Ke dua tools ini saya rasa begitu bermanfaat bagi teman-teman yang mengelola sebuah jaringan agar admin dengan mudah menebak IP address yang nakal dalam jaringannya. Sebenarnya masih banyak cara lain yang tak kalah mantafff dari cara ini tapi karena kita berbicara masalah Netcut dan monopoli bandwith dengan browser mozilla jadi saya rasa tools ini cukup… saya biasa menggunakan perintah “shutdown –i” di windows dan memasukkan ip address si anak nakal wkwkwkwk biasanya berhasil tapi bisa juga tidak… tapi cara paling ampuh menurut saya yah langsung datangin orangnya terus jewer telinganya wkwkwkwkwkwkwk. Mohon maaf kalau banyak kekurangan, tapi yah lumayan lah bukan hasil copy paste dari artikel orang, jadi kritikan dan saran tidak diterima belajar untuk selamanya (“ngutip kata-katanya mas Iswan Tri Wahudiono”)… wassalam;

Contoh konfigurasi di fire daemon untuk MRTG

# Move to your download folder.
cd /root/downloads
rpm -e mrtg
wget  http://www.dedicated-resources.com/files/mrtg-2.9.17-1cpanel.i386.rpm
Installing the app
rpm -Uvh mrtg-2.9.17-1cpanel.i386.rpm

Moving libpng
cd /usr/lib
mv libpng.so.2 libpng.so.2.OLD
# Creating the symlink
ln -s libpng.so.3 libpng.so.2
# Edit language at and specify only “en_US”
pico /etc/sysconfig/i18n

# Restarting MRTG
service mrtg restart

# Configurating MRTG to allow only our local IP to see the reports at

http://IP/mrtg

vi /usr/local/apache/conf/httpd.conf

#Search for the line (CTRL+W):
# It should look like this:

Options Indexes FollowSymlinks MultiViews
AllowOverride None
Order allow,deny
Allow from all

#After the last line () paste this and change allowed IPs:

order deny,allow
allow from [ SERVER IP ]
allow from [YOUR LOCAL IP]
deny from all

# Restarting httpd
service httpd restart
chkconfig –level 0123456 mrtg on

# Edit file:
pico /etc/mrtg/check-email

# Change to “*-H” “* -H”.
————————————————————————–

This guide explains how to  install MRTG on Windows and monitor different signals like memory and network usage.

MRTG is a software used to monitor different “signals” and display them in nice graphs.

I will use Windows XP as Operating System but it also works on Windows Server 2003.

Download MRTG

I will install mrtg-2.16.2 which can be downloaded here, however you should install the latest version which can be found here.

After downloading it, unpack it to where you want, I will use the following path: C:\mrtg-2.16.2

Install Perl

To run MRTG we need to install Perl first, I would recommend installing ActivePerl which can be found here.

It is pretty simple to install Perl so I won’t cover it, just follow the Setup.

Setting up the SNMP Service

Browse to Control Panel – Add or Remove Programs – Add / Remove Windows Components and then select Management and Monitoring Tools and then click Next.

You will probably be requested to insert the Windows CD to copy the required files.

After installing it, we need to configure it.

Browse to Control Panel – Administrative Tools – Services and then find the Service called SNMP Service, double-click on it and then select the Traps tab.

In the Community name textbox, write public and then click the button Add to list.

Now switch to the Security tab.

Add public to the Accepted community names with the READ ONLY community right.

Then select Accept SNMP packets from these hosts and add 127.0.0.1 to the list.

We have successfully configured SNMP on our Windows machine.

Install MRTG

Now we need access to a Command Prompt. Click Start – Run and then insert cmd and press enter.

In my case I have extracted the MRTG files to the following path: C:\mrtg-2.16.2

cd C:\mrtg-2.16.2\bin

Now we are going to create our MRTG configuration file, the WorkDir is the Path to where you want the files to be written, for example the public folder of your webserver.

perl cfgmaker public@127.0.0.1 –global “WorkDir: c:\xampp\htdocs\mrtg” –output mrtg.cfg

If it doesn’t output anything, then it means it worked.

perl indexmaker –output index.html mrtg.cfg

This will create an html file with the layout. Now copy that index.html file into your WorkDir (in my case c:\xampp\htdocs\mrtg)

copy index.html c:\xampp\htdocs\mrtg

Don’t forget to replace c:\xampp\htdocs\mrtg with your WorkDir!

Run MRTG

We still need a command-prompt. Execute the following commands

cd C:\mrtg-2.16.2\bin

perl mrtg mrtg.cfg

You have now manually triggered mrtg to get the data and draw it into the graphs.

Now we need to make this run automatically as it would be quite annoying if you had to manually run this command every 5 minutes..

Open your mrtg.cfg with a texteditor and add the line RunAsDaemon: yes

Now execute perl mrtg mrtg.cfg once again, MRTG has been started as a daemon, this is quite annoying because the command-prompt has to stay open. You can also create a Windows Service (Click here for additional informations)

Add Memory Usage and other Data sources

First we need to configure the inbuilt Performance Log of Windows. Click on Control Panel – Admistrative Tools – Performance – Performance Logs and Alerts then select Counter Logs, then right-click on the blank window and select New Log Settings.

Now we are going to create a new log, insert a name you want to use and then click OK.

A Counter is only one log, like the memory usage and an object is a collection of informations on memory for example.

Click the button Add Counters or Add Objects.

I am going to add a Counter for this example.

Select Use local Computer counters then select Memory in the Performance Object list then select Avaible MBytes and click Add then Close.

Then select the Log Files tab.

Select Text File(Comma delimited) in the Log file type listbox and then click OK.

Our .csv file is located at C:\PerfLogs\

We are now going to configure a .cfg file in MRTG to parse the .csv file which is created by the Windows Log Tool.

Please note that this script is a little bit buggy and the final results needs some tweaking, such as setting the MaxByte value in the graphs etc. The script has been written by castellan.net

Download the script here. If the link is broken download the mkcfg.vbs script here and the getlog.pl script here (Don’t forget to name the script getlog.pl)

We need a command-prompt.  Execute the following commands:

cd C:\mrtg-2.16.2\bin

cscript mkcfg.vbs c:\perflogs\memory.csv memory

This should create 2 files, .html and .cfg.

This is a little bit tricky, the mkcfg.vbs script is a little bit bugy, it repeats the last diagram a couple of times, so open up the memory.cfg with a text-editor and locate the duplicate diagrams. (Should be easy to spot)

After you deleted them, you need to change the WorkDir.

Copy the created .html file into your public mrtg folder and then execute this

perl mrtg memory.cfg

You have created a new graph display for your .csv file! (Don’t forget to update this .cfg file too, refer to Run MRTG for more help)

If the legend isn’t big enough, change MaxBytes in the .cfg file.

You can also include memory.cfg into mrtg.cfg . Add the following line into mrt.cfg

Include: memory.cfg

Indexmaker

Doesn’t it annoy you that you have to visit 2 links to admire your graphs? Indexmaker can bind them together into one page.

perl indexmaker –output index.html mrtg.cfg memory.cfg

This command will bind both mrtg.cfg and memory.cfg into one file, named index.html. Now copy the index.html file into your WorkDir. That’s it. If you want to see detailed informations about a graph, click on it.

Finally

You might want to rename your legends and titles to make the graphs more readable.

I hope this quick guide was somewhat useful, if you have any questions, feel free to post a comment.

Thanks for reading and good luck.

Well, going by what actually happened at the National Internet Backbone’s nodal center in Jaipur, a more apt title would have been something like:

“Attempt at Setting up MRTG for BSNL, Jaipur, Swiftly Denied by a Network Problem”

Like I mentioned before, we had some serious network related issues when we were trying to configure the (really old) server they’d given us to setup MRTG on. We were to configure the network interface settings on the Red Hat server according to a hand book they’d given me. After setting the IP and the subnet mask, I went on to add the default gateway route. And heck, the gateway wasn’t visible from the LAN! I thought that perhaps, the hand book had older details and they’d probably reconfigured their routers in the server room we were in. But when Mr S.C Gupta, the head of the nodal office, told me that all other hosts in the same network are using the gateway that was specified in the manual (which was Rajasthan’s gateway to the internet backbone), I was taken aback. Not once in my system administration experience had I encountered a situation where a router was visible to all hosts but one within the same VLAN (assuming no one went through the trouble of setting a port block in the switch)! Furthermore, I was able to ping all these hosts from the server in question and vice versa, but the router still stood defiant (when I get my hands on it…grrr). My suspicion about the router having disabled incoming pings were also put to waste when I saw that it’s working with the other devices on the same LAN. Just to be sure, I checked and double checked the configuration of all other systems on the network, and they all seemed green. How queer. To make matters worse, no one really knew how these devices were networked. After tackling the problem for about 4 hours, me and my junior Nitin, decided to leave and come back some other time because the station was to go on a power maintenance shutdown. Man was I glad I left that place!

Something lacking in a lot of environments is the ability to watch bandwidth throughout the network.  Being able to monitor this bandwidth is extremely helpful when troubleshooting random network issues and being able to determine where the problem is.  SNMP is built into most switches, routers, and firewalls these days and the reason to use it, in my opinion, far outweigh the reasons not to use it.  If you are using Cisco gear (and frankly if you aren’t you should) here are a quick couple commands you can use to set up SNMP quickly.

IOS Commands:
snmp-server host <monitoring host> traps public
snmp-server enable traps
snmp-server community public

ASA Commands:
snmp-server community public
snmp-server enable traps
snmp-server host inside <monitoring host> poll

The <monitoring host> is a server that you have set polling the information from these devices.  A good program that we use in house at eGroup is SolarWinds and MRTG which I highly recommend.

Gunnar Berger, eGroup
http://www.eGroup-us.com

ini berlaku untuk semua jenis distro:

wget http://serveio. com/da/install. mrtg.sh
chmod +x install.mrtg. sh
./install.mrtg. sh

sebelum jalankan scripnya pastikan direktori /var/www/html/mrtg ada.

kalo masih terjadi error pastikan libgd terinstall
wget http://www.libgd. org/releases/ gd-2.0.35. tar.bz2
tar -xjvf gd-2.0.35.tar. bz2
cd gd-2.0.35
sudo su
./configure
make
make install

jalankan lagi scriptnya, good luck!!

untuk info lanjut:
http://www.directad min.com/forum/ showthread. php?threadid= 7843

Buenas despues de tanto tiempo si escribir debido a un problema con mi internet casero:P VUELVO!

bueno en este post me quiero referir a la cantidad de software de monitoreo basado en linux que se encuentra en la red, estos software nos dan la posibilida de tener una vision real de lo que ocurre en nuetra red si que se escape ningun detalle y tomar las medidas pertinentes si algo esta ocurriendo.

De las herramientas de monitoreo mas conocidas se encuentra NAGIOS una aplicacion que es muy versatil ya que puede monitorear equipo por SNMP y esto le da un sin fin de posibilidades.

luego se encuentra MRTG que nos muestra Grafico de utilizacion de cualquier cosa que queramos(Bandwidth, temperaturas, etc…)

por otro lado se encuentran aplicaciones mas especificas como SNORT, CACTI, NTOP, MUNIN y otras que en este momento no recuerdo.

pero lo bueno seria que existiera una distribucion que agrupara todos estos software de monitoreo y para mi sorpresa despues de unos contactos con unos amigo me encuentro con que existe y se llama OSSIM una Distribucion basada en Debian que agrupa todas estas aplicaciones y es administrable por medio de SSH o via WEB

Current post is about how to getting MRTG log file from MRTG Server. Usually MRTG is far from our client (reside in ISP/NOC).  Why this howto is important? Because technically we must download the MRTG log file everyday in order to get the finest data (5 minutes average). As you know every day MRTG will rotate its log file with 5 minutes average data only in two days range. So, once again, this procedure must be executed to get the finest data of Internet traffic by using MRTG.

Ok, let us start to discuss it . I assume all of log file are reside in MRTG_SERVER and we want to download it to our client for analysis  named CLIENT :

1. We will use software called rsync, the famoust backup software in linux.
2. Here is my bash script in CLIENT (named backup.sh):


#/bin/bash
rsync -e ssh user@MRTG_SERVER:/tmp/MRTG/escape_1.log destination_dir/`date +%Y%m%d`escape_1.log
rsync -e ssh user@MRTG_SERVER:/tmp/MRTG/mail/data.log destination_dir/`date +%Y%m%d`numbermail.log
rsync -e ssh user@MRTG_SERVER:/tmp/MRTG/mailsize/data.log destination_dir/`date +%Y%m%d`sizemail.log
rsync -e ssh user@MRTG_SERVER:/tmp/MRTG/login/data.log destination_dir/`date +%Y%m%d`numberlogin.log


In this example, there four logfiles tobe copied : escape_1.log (the Internet traffic ), mail/data.log (the number of mail received and sent mesages), mailsize/data.logmail/data.log (the size of mail received and sent mesages), login/data.log (the number of user login in mailserver).

3. After creating the script file, we then set the automatic ssh login (no password console appears whe doing rsync). At first we login to the CLIENT, and execute command : ssh-keygen -t rsa.
   
user@CLIENT:~> ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/user/.ssh/id_rsa):
Created directory '/home/user/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/user/.ssh/id_rsa.
Your public key has been saved in /home/user/.ssh/id_rsa.pub.
The key fingerprint is:
3e:4f:05:79:3a:9f:96:7c:3b:ad:e9:58:37:bc:37:e4 user@CLIENT

4. Copy the file : id_rsa.pub to your .ssh directory in MRTG_SERVER. And then rename it to : authorized_keys
5. Change the permissions of .ssh directory in MRTG_SERVER to 700. FROm now, you can login to MRTG from CLIENT automatically (without password)
6. Create user crontab for running the script backup.sh. From CLIENT terminal run crontab -e. Then edit as follows:
   
0 23 * * * sh 'backup_MRTG_1.sh' >/dev/null 2>&1 #JOB_ID_1

   This means we want to run the script everyday every 23:00 PM.

Neste artigo mostrarei como monitorar as Interfaces de Rede e também os clientes de um roteador linux utilizando o MRTG. Neste exemplo estou utilizando um Servidor Lunux Ubuntu com regras de NAT, mas pode ser adaptado facilmente para outras distribuições ou necessidades.

Também utizaremos o IPFM que fará a contabilização do tráfego utilizado pelos IPs que passam pelo roteador linux.

Instalando Programas necessários:

# apt-get install mrtg ipfm

Configurando o MRTG

# mkdir /etc/mrtg
# mkdir /etc/mrtg/scripts
# mkdir /var/www/mrtg

O primeiro é o diretório onde fica guardado o arquivo de configuração (normalmente mrtg.cfg). O segundo é onde ficarão os scripts necessários para o monitoramento e o terceiro diretório é onde estarão as páginas criadas para a visualização dos gráficos.

Criando os Scripts

IFVMON.SH (para monitorar os IPs de clientes)
# vi /etc/mrtg/scripts/ifvmon.sh

# Script Feito por Jefferson Aranha Dos Santos
# Jefferson.aranha@gmail.com
# Passando como 1º parâmetro o caminho completo do log do ipfm e 2º
# parâmetro um ip
#!/bin/bash
cat "$1" | grep "$2 " > /dev/null
if [ "$?" -ne 0 ]
then
echo 0
echo 0
else
cat "$1" | grep "$2 " | awk '{print $2"\n"$3}'
fi

MRTG.CFG

Language: brazilian
EnableIPv6: no
RunAsDaemon: Yes
Interval: 5
WorkDir:/var/www/mrtg
Logdir: /var/log/mrtg
Options[_]: bits,growright
#
Target[eth0]:`/etc/mrtg/scripts/ifmon.sh eth0`
Title[eth0]:"Trafego Internet - eth0"
Maxbytes[eth0]:1400000
PageTop[eth0]:<h1>Trafego Internet - eth0</h1>
Options[eth0]: growright,bits,noinfo
#
Target[eth1]:`/etc/mrtg/scripts/ifmon.sh eth1`
Title[eth1]:"Trafego Clientes - eth1"
Maxbytes[eth1]:1400000
PageTop[eth1]:<h1>Trafego Clientes - eth1</h1>
Options[eth1]: growright,bits,noinfo
#
Target[loopback]:`/etc/mrtg/scripts/ifmon.sh lo`
Title[loopback]:"Trafego da Loopback - lo"
Maxbytes[loopback]:1400000
PageTop[loopback]:<h1>Trafego da Loopback - lo</h1>
Options[loopback]: growright,bits,noinfo
#
Target[192.168.1.100]:`/etc/mrtg/scripts/ifvmon.sh /var/log/ipfm/subnet/ipfm.log 192.168.1.100`
Title[192.168.1.100]:"Trafego do IP - 192.168.1.100"
Maxbytes[192.168.1.100]:1400000
PageTop[192.168.1.100]:<h1>Trafego do IP - 192.168.1.100</h1>
Options[192.168.1.100]: growright,bits,noinfo

Salvo se eu tenha esquecido de alguma coisa, o MRTG agora está pronto para funcionar, portanto vamos às finalizações:

Executando o IPFM

# ipfm -c /etc/ipfm.conf

Gerando a página que mostrará os gráficos

# indexmaker –output=/var/www/mrtg/index.html /etc/mrtg/mrtg.cfg

Executando o MRTG

# env LANG=C /usr/bin/mrtg /etc/mrtg/mrtg.cfg –logging /var/log/mrtg.log

Deixem suas dicas e sugestões nos comentários.
Eduardo Supertrix

Slowly but surely, I’ve been moving our home network to an architecture that wouldn’t keep me up at night. Since we needed both wireless and wired access, my primary goal was to design a network that would allow wireless clients to access the internet but not the rest of our network — I expect that a determined user could get on our wireless network with or without the password, but our wired machines shouldn’t be exposed unless someone gains physical access to our hardware.

Click to enlarge

The diagram above shows how I ended up solving this. The solution relies heavily on having separate subnets for wired and wireless traffic… in this case, a ZyWALL 2 Plus lets me set up and control access between these networks.

The ZyWALL has the added benefit of SNMP support, which means one of my client machines can use mrtg to graph our network activity:

Click to view more statistics

Looking to the future, our router and switch give us fine-grained controls over the bandwidth used by each client on our wired network. I haven’t done much with this yet, but I anticipate putting it to use when we have a couple of kids accessing the internet.

Ho illustrato nel post dedicato al protocollo SNMP, come è    possibile gestire ed intervenire su sistemi raggiungibili dalla rete. Oggi vi mostro come poter tradurre le informazioni catturate dal server snmp in tabelle aggiornate. Un modo di tradurre interrogazioni visibili testualmente in tabelle con dati statistici, con MRTG. Ora vediamo di capire come funziona e cosa ci serve. MRTG, acronimo di Multi Router Traffic Grapther, scritto in perl, è forse il più famoso monitor di rete, il quale analizza il traffico in ingresso e in uscita. Permette, settando un ciclo di aggiornamento, di conoscere le statistiche di traffico della rete, utilizzo del sistema nei sui componenti hardware, connessioni tcp. Le informazioni fornite comprendono statistiche giornaliere, settimanali e annuali, in formato tabella e testuale. Vediamo cosa ci serve per poter mettere in piedi l’architettura:

1. mrtg

1. mrtg-contrib

1. librrds-perl

1. snmpd

1. snmp

Se avete seguito la configurazione dell’agent snmpd, siete a metà lavoro, altrimenti seguite prima questa piccola guida.

Ora che snmpd è pronto ed installate le librerie, iniziamo con la configurazione.

Quando installate mrtg, esso vi analizza le vostre impostazioni di rete e crea un file mrtg.conf in /etc/mrtg.conf. Se leggete il file, noterete che mrtg andrà a salvare i suoi grafici in /var/www/mrtg. Potete sempre cambiarle, ma resta il fatto che, qualunque  path scegliate, questo deve esistere. Ora, lasciando quello scelto da mrtg, /var/www/mrtg, diamo i permessi in modo che possa scrivere nelle cartelle del filesystem in questo modo:

chown root:root /var/www/mrtg

chmod 755 /var/www/mrtg

E’ tutto pronto, faccendo partire snmpd, mrtg è gia pronto. Infatti se lanciate il comando  env LANG=C /usr/bin/mrtg /etc/mrtg.cfg, troverete i grafici sul path scelto, in questo caso quello di default.

Abbiamo la possibilità, però, di apportare delle migliorie, ovvero utilizzare l’interfaccia web per visualizzare i grafici, inoltre, aggiungere altre statistiche come le connessioni tcp o di sistema come utilizzo cpu, memoria ed altro.

Per l’interfaccia web, installiamo Apache2, per gli utenti Ubuntu, vi rimando al wiki di apache.

Per aggiungere informazioni da catturare, andate qui e scegliete quelle che possono esservi utili. Quelle scelte saranno inserite nel nuovo file .cfg che andremo a creare.

Supponiamo di aver scelto, tcp oltre al networking che mrtg gia conosce e seguiamo questi due step

Scegliete la community da analizzare, avete seguito il post snmp vero? Altrimenti non sapete di che parlo e non funzionerà nulla. Supponiamo di voler utilizzare mrtg per la community host, ovvero quella locale. Da terminale lanciate il comando per la creazione del file cfg

cfgmaker host@localhost >networking.cfg

Abbiamo creato il file cfg identico a mrtg.cfg ma con l’intenzione di aggiungre le info tcp. Ecco il mio

# tcp connections
WorkDir: /var/www/mrtg
IconDir: /var/www/mrtg/image
RunAsDaemon:yes
Target[tcpopen]: .1.3.6.1.2.1.6.9.0&.1.3.6.1.2.1.6.9.0:host@localhost
Options[tcpopen]: nopercent,growright,gauge,noinfo
Title[tcpopen]: Open TCP connections
MaxBytes[tcpopen]: 1250000
PageTop[tcpopen]: <H1>Open TCP connections</H1>
YLegend[tcpopen]: # conns
ShortLegend[tcpopen]: connections
LegendI[tcpopen]:  Connections:
LegendO[tcpopen]:
Legend1[tcpopen]: Open TCP connections

Ho scelto la stessa directory mrtg ma ho aggiunto quella per il salvataggio delle immagini per non mischiare tutto dentro un unico path. Il file cfg chiamatelo come vi pare e salvatelo dove vi pare, io in /var/www/mrtg/cfg/.

Ora creiamo l’index.html per la home page dove verranno inseriti i dati e tabelle.

indexmaker networking.cfg > /var/www/mrtg/index.html

Se avete intenzione, come è ovvio altrimenti che ve ne fatte di mrtg, di utilizzare mrtg come demone, nella definizione per le catture tcp, lasciate yes in RunAsDaemon:yes, altrimenti mettete no.

Ora siamo pronti, avviate apache, /etc/init.d/apache2 start, avviate snmpd, /etc/init.d/snmpd start, e lancaite mrtg con env LANG=C /usr/bin/mrtg /var/www/mrtg/networking.cfg, oppure mettete il vostro path. Se avete un firewall, aprite le porte 80 per apache2, se non le avete cambiate, 161 per snmp. Ora su localhost:80/mrtg avrete le tabelle che, di default, ogni 5 minuti si aggiornano.

Ecco uno stupido scritp per automatizzare la procedura:

#!/bin/bash
case “$1″ in
start)
/etc/init.id/snmpd start
/etc/init.id/apache2 start
env  env LANG=C /usr/bin/mrtg /var/www/mrtg/cfg/tot.cfg
;;
stop)
/etc/init.id/snmpd stop
/etc/init.id/apache2 stop
;;
restart)
/etc/init.id/snmpd restart
/etc/init.id/apache2 restart
env  env LANG=C /usr/bin/mrtg /var/www/mrtg/cfg/tot.cfg
;;
esac
exit 0