Curs 03 - Monitorizarea reteleirepository.grid.pub.ro/cs/saisp/cursuri/curs-03.pdfMonitorizarea ret, elei I Network monitoring I Monitorizare constant a a unei ret ele de calculatoare

Curs 03Monitorizarea ret,elei

Servicii avansate pentru ISP

6 martie 2017

SAISP Curs 03, Monitorizarea ret,elei 1/49

Outline

Introducere

SNMP

Round Robin Database

Nagios

Alte solut, ii de monitorizare

Monitorizarea traficului

Concluzii

Intrebari


Monitorizarea ret,elei

I Network monitoring

I Monitorizare constanta a unei ret,ele de calculatoare

I Componente care cedeaza sau care funct, ioneaza ıncet

I Utilizare curenta de resurse

I Asigurarea unui nivel de disponibilitate

I Notificarea administratorului

I Subset al network management (autentificare, autorizare, loadbalancing, accounting etc.)




















Disponibilitate ın monitorizare

I Disponibilitate (availability) – utilizatorul poate accesasistemul

I DowntimeI planificat (patching/updates, system configuration)I neplanificat (hardware faults, power outage, security breaches,

software failures)

I Uptime – procent de uptimeI 99.9%, 99.99%, 99.998%, 99.9999% (six nines) (31.5

secunde/an downtime)I folosite ın marketing – the myth of the nines

I Uptime != disponibilitate (fizic up, dar inaccesibil din ret,ea)

I SLA – Service Level Agreement





software failures)









software failures)









software failures)






Principii de monitorizare

I “input” de la utilizatori

I “less is more”

I Abordare iterativa (ce este important? ce este critic?)

I Start high-level and work down the application stack

I Monitorizare de servicii s, i dispozitive

I MOM – Monitor of Monitors


Masurarea/monitorizarea traficului

I Captura (selectiva) de trafic

I Contabilizare/accounting

I Logging, rendering

I Util pentru: masurarea ıncarcarii ret,elei, tipuri de trafic,stat, iile/ret,elele cele mai ıncarcate, QoS, detectare flood-uri,funct, ionalitatea unui protocol, debugging


Outline

Introducere

SNMP


Nagios



Concluzii

Intrebari


SNMP

I Simple Network Management Protocols

I SNMP password (community string)

I v1, v2c - necriptat (parola = community string)

I v3 - criptatI OID – object identifiers (statistici operat, ionale)

I .1.3.6.1.4.1.789.1.6.4.8.0I .iso.org.dod.internet.private.enterprises.netapp.

netapp1.raid.diskSummary.diskSpareCount.0

I fully qualified OID (.iso.org.dod.internet.private)I aproape toate sunt urmate de oid-ul enterprisesI si de vendor ID (alocat de IANA)I http://www.iana.org/assignments/enterprise-numbers


SNMP

I Simple Network Management Protocols

I SNMP password (community string)

I v1, v2c - necriptat (parola = community string)

I v3 - criptatI OID – object identifiers (statistici operat, ionale)

I .1.3.6.1.4.1.789.1.6.4.8.0I .iso.org.dod.internet.private.enterprises.netapp.

netapp1.raid.diskSummary.diskSpareCount.0I fully qualified OID (.iso.org.dod.internet.private)I aproape toate sunt urmate de oid-ul enterprisesI si de vendor ID (alocat de IANA)I http://www.iana.org/assignments/enterprise-numbers


Management Information Base

I MIB – Management Information BaseI Fis, iere ce definesc funct, iile OID-urilor

I .iso.org.dod.internet.private.enterprises.netapp.netapp1.raid.diskSummary.diskSpareCount.0

I NETWORK-APPLIANCE-MIB::diskSpareCount.0

I MIB_Name::Unique_Key.instance

I Ce reprezinta o instanta ın acest caz?

I numarul disk-ului


Management Information Base

I MIB – Management Information BaseI Fis, iere ce definesc funct, iile OID-urilor

I .iso.org.dod.internet.private.enterprises.netapp.netapp1.raid.diskSummary.diskSpareCount.0

I NETWORK-APPLIANCE-MIB::diskSpareCount.0

I MIB_Name::Unique_Key.instance

I Ce reprezinta o instanta ın acest caz?I numarul disk-ului


OID & MIB


SNMP pe Linux

I apt-get install snmp snmpd

I 1 root@valhalla:/tmp# snmp2 snmpbulkget snmpdf snmpnetstat snmptest

snmpvacm

3 snmpbulkwalk snmpget snmpset

snmptranslate snmpwalk

4 snmpconf snmpgetnext snmpstatus snmptrap

5 snmpdelta snmpinform snmptable snmpusm

I 1 root@valhalla:/tmp# netstat -ulpn | grep snmpd2 udp 0 0 127.0.0.1:161 0.0.0.0:*

2983/snmpd


snmpd

I /etc/default/snmpd

I /etc/init.d/snmpd

I /etc/snmpd/snmpd.conf

I man 5 snmpd.conf

I configurare community stringI com2sec readonly localhost public

I root@valhalla:/tmp# snmpwalk -Os -c public -v 1

localhost | wc -l

2678


Statistici SNMP

I system uptimeI $ snmpget -v 2c -c public localhost

.1.3.6.1.2.1.1.3.0

iso.3.6.1.2.1.1.3.0 = Timeticks: (55298)

0:09:12.98

I total RAM in machineI $ snmpget -v 2c -c public localhost

.1.3.6.1.4.1.2021.4.5.0

iso.3.6.1.4.1.2021.4.5.0 = INTEGER: 1929536

I http://www.debianadmin.com/

linux-snmp-oids-for-cpumemory-and-disk-statistics.

html

I scli


http://www.debianadmin.com/linux-snmp-oids-for-cpumemory-and-disk-statistics.html



Outline

Introducere

SNMP


Nagios



Concluzii

Intrebari


RRDTool

I Dezvoltat de Tobias Oetiker, system manager la Swiss FederalInstitute of Technology

I apt-get install rrdtool

I Date stocate ın fisiere .rrd cu rol de baza de date

I Genereaza grafice pe baza datelor stocateI Operatiile se realizeaza cu utilitarul rrdtool:

I createI updateI graph


Caracteristici baze de date RRD

I Dimensiunea este constanta, stabilita la creare

I Configurabil sa stocheze rata de schimbare, nu valoarea ın sineI Are nevoie de valori la intervale predefinite de timp

I ın caz ca nu primeste, stocheaza valoarea speciala UNKNOWN

I Pentru fiecare valoare stocheaza si un timestampI date stocate ca serii de timp

I Defineste variabile si modul de arhivare


Exemplu RRD

rrdtool create target.rrd \

--start 1023654125 \

--step 300 \

DS:mem:GAUGE:600:0:671744 \

RRA:AVERAGE:0.5:12:24 \

RRA:AVERAGE:0.5:288:31

I DS:variable_name:DST:heartbeat:min:max

I DS - Data Source

I DST - Data Source Type

I hearbeat - timpul maxim de astepare al unei noi valori

I min, max - intervalele ıntre care se accepta o noua valoare


Data Source Types

I COUNTER - rata de schimbare

I DERIVE - permite valori negative

I ABSOLUTE - presupune valoarea anterioara ca fiind 0

I GAUGE - valoarea ın sine

Values = 300, 600, 900, 1200

Step = 300 seconds

COUNTER DS = 1, 1, 1, 1

DERIVE DS = 1, 1, 1, 1

ABSOLUTE DS = 1, 2, 3, 4

GAUGE DS = 300, 600, 900, 1200


Data Source Types

I COUNTER - rata de schimbare

I DERIVE - permite valori negative

I ABSOLUTE - presupune valoarea anterioara ca fiind 0

I GAUGE - valoarea ın sine

Values = 300, 600, 900, 1200

Step = 300 seconds

COUNTER DS = 1, 1, 1, 1

DERIVE DS = 1, 1, 1, 1

ABSOLUTE DS = 1, 2, 3, 4

GAUGE DS = 300, 600, 900, 1200


Round Robin Archive

I RRA:CF:xff:step:rows

I CF: AVERAGE, MINIMUM, MAXIMUM, LAST

I step - numarul de valori agregate

I numarul de agregari retinute

rrdtool create target.rrd \

--start 1023654125 \

--step 300 \

DS:mem:GAUGE:600:0:671744 \

RRA:AVERAGE:0.5:12:24 \

RRA:AVERAGE:0.5:288:31


Outline

Introducere

SNMP


Nagios



Concluzii

Intrebari


Nagios

I “The Industry Standard in IT Infrastructure Monitoring”

I http://www.nagios.org/

I Monitorizarea statiilorI starea resurselor (memorie, procesor, disc)I temperatura

I Monitorizarea serviciilor (protocoale de retea)I SMTPI HTTPI SSH


Nagios (cont.)

I Genereaza alerte catre contactele definite

I Genereaza statistici/rapoarte

I Calculul automat al disponiblitatii

I Extensibil prin plugin-uri

I Interfata web (vizualizare status echipamente)


Obiecte s, i definit, ii

I timeperiodI operational hoursI timeperiods.cfg

I commandI map to external commandsI commands.cfg

I contact, contactgroupI send notifications (to contactgroups)I contacts.cfg, contactgroups.cfg

I host, hostgroupI physical entities (servers, routers)I hosts.cfg, hostgroups.cfg

I service, servicegroupI hosts provide services (majority of configurations)I service.cfg, servicegroups.cfg


Interactiuni ıntre obiecte

Service

Contact

Host

Service Group

Time Period

Host Group

Contact Group


Instalare

I apt-get install nagios3 nagios-plugins

I /etc/nagios3/nagios.cfg

I /etc/nagios3/

I /etc/nagios3/apache.conf

(http://hostname/nagios3/)

I /etc/nagios-plugins/config/

I /etc/init.d/nagios3 start|stop|restart


http://hostname/nagios3/

Comenzi de monitorizare

I prin pluginuri

I /usr/lib/nagios/plugins/check_*

I configurate ın /etc/nagios-plugins/config/*.cfgkoala:/etc/nagios-plugins/config# cat apt.cfg

# ’check_apt’ command definition

define command{

command_name check_apt

command_line /usr/lib/nagios/plugins/check_apt

}

# ’check_apt_distupgrade’ command definition

define command{

command_name check_apt_distupgrade

command_line /usr/lib/nagios/plugins/check_apt -d

}


Funct, ionare comenzi de monitorizare / plugin-uri

I pot fi scrise de utilizatorI programe care ıntorc un cod de eroare specific

I 0 – OKI 1 – WarningI 2 – CriticalI 3 – Unknown

define service{

hostgroup_name procload

service_description Total Processes

check_command check_procs!200!400

...


Template-uri

I “capture redundant definitions inside special definitions”I pentru host-uri s, i servicii

# This is my template

define host{

name hostTemplate

check_command check-host-alive

max_check_attempts 5

contact_groups admins

notification_interval 30

notification_period 24x7

notification_options d,u,r

register 0

}

# myHost is shorter now that it inherits from hostTemplate

define host{

host_name myHost

alias My Favorite Host

address 192.168.1.254

parents myotherhost

use hostTemplate

}


Procesul de configurare Nagios

I creare template-uri (skeleton files) pentru host-uri s, i servicii

I creare fis, iere de configurare pentru host-uri s, i servicii

I creare contacte s, i grupuri de contacte

I configurat comenzi folosite/plugin-uri etc.


Plugin-uri

I comenzi care extind funct, ionalitatea data de nagios-core

I http://nagiosplugins.org/

I ./check_* --help


Scenariu de configurare

I check_ssl_certI http://exchange.nagios.org/directory/Plugins/

Network-Protocols/HTTP/check_ssl_cert/details

I dezarhivare s, i copiere ın $USER1$ (configurat ın/etc/nagios3/resource.cfg)

I ın commands.cfg se adauga comandadefine command{

command_name check_ssl_cert

command_line $USER1$/check_ssl_cert -r /etc/ssl/certs/ -H $HOSTADDRESS$

}

I se adauga un hostgroup ın hostgroups.cfgI se configureaza serviciul ın services.cfg

# define a service to check SSL certificates

define service{

hostgroup_name ssl_cert

service_description valid SSL certificates

check_command check_ssl_cert

use generic-service

notification_interval 0

}


http://exchange.nagios.org/directory/Plugins/Network-Protocols/HTTP/check_ssl_cert/details

http://exchange.nagios.org/directory/Plugins/Network-Protocols/HTTP/check_ssl_cert/details

nagstamon

I http://nagstamon.sourceforge.net/

I Nagios status monitor for the desktop

I Systray sau status bar

I Informatii detaliate la mouse hover

I Acces rapid prin SSH/RDP/VNC din meniul contextual

I Poate controla ce notificari sa primeasca

I Pentru un server Nagios, trebuie completate campurileServer URL s, i Server CGI URL


NRPE

I Nagios Remote Plugin ExecutorI check_nrpe ruleaza local, un daemon ruleaza pe host-urile

monitorizateI check_nrpe solicita catre daemon executarea de comenzi

I /etc/nagios/nrpe.cfg


Nagios XI

I Varianta comerciala a Nagios-Core

I Simplifica administrarea

I Grafice folosind datele colectate

I Sistem de ticketingI User interface

I framework pentru configurare si administrareI customizabil pentru fiecare utilizator


Outline

Introducere

SNMP


Nagios



Concluzii

Intrebari


MRTG

I Multi Router Traffic GrapherI monitorizarea ıncarcarii traficului

I ın momentul de fat, a creeaza grafice s, i statistici din situat, iidiverse

I RRDtool (Round Robin Database Tool) – grafice

I apt-get install mrtg


Cacti

I network graphing solution

I MySQL database

I SNMP support

I RRDTool

I data retrieval, data storage, data presentation

I apt-get install cacti


Zabbix

I enterprise-class open source distributed monitoring solutionI server-agent

I server care colecteaza informat, iileI un agent ruleaza pe fiecare hostI datele sunt stocate ıntr-o baza de date

I apt-get install zabbix-server-mysql

I apt-get install zabbix-agent

I http://kkovacs.eu/zabbix-vs-nagios


http://kkovacs.eu/zabbix-vs-nagios

Munin

I arhitectura de tip master/node (similara Nagios)

I foloses, te RRDTool

I prezinta grafice ıntr-o interfat, a web (recunoscut pentru acestlucru)

I extensibil prin plugin-uri


Monit

I system monitoring tool

I monitorizarea s, i gestiunea resurselor ıntr-un sistem Unix

I procese, fis, iere, directoare

I pornire, oprire, repornire servicii

I monitorizare + alerte

I apt-get install monit

I /etc/monit/monitrc


Outline

Introducere

SNMP


Nagios



Concluzii

Intrebari


Solut, ii de monitorizare a traficului

I Top 6 Traffic Monitoring Toolshttp://sectools.org/traffic-monitors.html

I sniffing (tcpdump, Ethereal)

I interceptare (netfilter, iptables)

I solut, ii dedicate: ntop, ngrep, iftop, vnstat, iptraf


http://sectools.org/traffic-monitors.html

iptables

1 iptables -N my-network

2 iptables -A FORWARD -s 192.168.1.0/24 -j my-network

3 iptables -A FORWARD -d 192.168.1.0/24 -j my-network

4 iptables -L FORWARD -n -v


ntop, ngrep, iftop

I ntopI statistici vizuale despre traficul de ret,eaI poate rula ca daemonI trebuie rulat prima data obis,nuit pentru configurare paroleiI un server web asculta pe portul 3000I foloses, te RRDTool

I ngrep -d lo -x GET

I iftop – statistici top-like (top, htop, iotop) pentru traficul deret,ea


iptraf, vnstat

I iptrafI network statistics utilityI TUI

I sudo vnstat -u -i eth0

I vnstat


Outline

Introducere

SNMP


Nagios



Concluzii

Intrebari


Cuvinte cheie

I monitorizare

I high availability

I uptime, downtime

I SLA

I SNMP

I OID

I MIB

I snmpd

I community string

I scli

I Nagios

I pluginuri

I obiecte s, i definit, ii

I nagstamon

I NRPE

I MRTG

I RRDTool

I Cacti

I Zabbix

I Munin

I monit

I iptables

I ntop

I ngrep

I iftop

I iptraf

I vnstat


Link-uri utile

I http://en.wikipedia.org/wiki/Comparison_of_network_

monitoring_systems

I http://www.slac.stanford.edu/xorg/nmtf/nmtf-tools.html

I http://www.topology.org/comms/netmon.html

I http://www.linuxhomenetworking.com/wiki/index.php/Quick_

HOWTO_:_Ch22_:_Monitoring_Server_Performance

I http://www.debianhelp.co.uk/snmp.htm

I http://www.debuntu.org/

how-to-monitor-your-servers-with-snmp-and-cacti

I http://www.debianadmin.com/

linux-snmp-oids-for-cpumemory-and-disk-statistics.html

I http://www.nagios.org/

I http://oss.oetiker.ch/mrtg/


http://en.wikipedia.org/wiki/Comparison_of_network_monitoring_systems

http://en.wikipedia.org/wiki/Comparison_of_network_monitoring_systems

http://www.slac.stanford.edu/xorg/nmtf/nmtf-tools.html

http://www.topology.org/comms/netmon.html

http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch22_:_Monitoring_Server_Performance

http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch22_:_Monitoring_Server_Performance

http://www.debianhelp.co.uk/snmp.htm

http://www.debuntu.org/how-to-monitor-your-servers-with-snmp-and-cacti

http://www.debuntu.org/how-to-monitor-your-servers-with-snmp-and-cacti



http://www.nagios.org/

http://oss.oetiker.ch/mrtg/

Outline

Introducere

SNMP


Nagios



Concluzii

Intrebari


Documents

Curs 03 - Monitorizarea reteleirepository.grid.pub.ro/cs/saisp/cursuri/curs-03.pdfMonitorizarea ret, elei I Network monitoring I Monitorizare constant a a unei ret ele de calculatoare