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Como usar IPtables para balanceamento de carga no gateway

tag-icon • tag-icon networking iptables ip nat
Como usar IPtables para balanceamento de carga no gateway

Eu tenho 3 placas de rede. NIC1 e NIC2 são usados ​​para conexões de internet e uma LAN é usada para conexão de intranet.

Quero equilibrar a carga para ISPs usando tabelas IP. Como sou novato, minha tentativa grosseira é dada no código a seguir, obviamente sem sucesso. Este código foi montado consultando vários sites sobre o assunto.

gostaríamos de usar de forma otimizada a entrada de Internet na LAN usando o método Round-Robin

ou

É possível dividir os dois ISPs, ou seja, para os sistemas 1 a 5 (ISP1) e 5 a 10 (ISP2) utilizando tabelas de roteamento?

Espero que alguém me ajude, o que é muito apreciado.

set -x
IPT="/sbin/iptables"
NIC1="enp4s5f0"
NIC2="enp4s5f1"
LAN="ens2"
ISP1="192.168.9.33"
ISP2="192.168.10.33"

#***************
# reset iptables
#_______________
## reset the default policies in the filter table.
$IPT -P INPUT ACCEPT
$IPT -P FORWARD ACCEPT
$IPT -P OUTPUT ACCEPT

## reset the default policies in the nat table.
$IPT -t nat -P PREROUTING ACCEPT
$IPT -t nat -P POSTROUTING ACCEPT
$IPT -t nat -P OUTPUT ACCEPT

## reset the default policies in the mangle table.
$IPT -t mangle -P PREROUTING ACCEPT
$IPT -t mangle -P OUTPUT ACCEPT

## flush all the rules in the filter and nat tables.
$IPT -F
$IPT -t nat -F
$IPT -t mangle -F

## erase all chains that's not default in filter and nat table.
$IPT -X
$IPT -t nat -X
$IPT -t mangle -X


#*********************
# enable IP forwarding
#_____________________
echo 1 > /proc/sys/net/ipv4/ip_forward


#****************
# rules 
#________________
$IPT -A INPUT -m state --state INVALID -j DROP 
$IPT -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT 
$IPT -A INPUT -p icmp -j ACCEPT 
$IPT -A INPUT -p tcp -m tcp --dport 22 -j ACCEPT 
$IPT -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT 

$IPT -A FORWARD -m state --state INVALID -j DROP 
$IPT -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT 
$IPT -A FORWARD -p icmp -j ACCEPT 

$IPT -t nat -A PREROUTING -i NIC1 -p tcp --dport 80\ 
            -m state --state NEW -m statistic --mode\ 
            random --probability .33 -j  DNAT --to-destination 10.1.1.1:1

$IPT -t nat -A PREROUTING -i NIC2 -p tcp --dport 80\ 
            -m state --state NEW -m statistic --mode\ 
            random --probability .33 -j  DNAT --to-destination 10.1.1.1:2

$IPT -A FORWARD -i $NIC1 -o $LAN -j ACCEPT
$IPT -A FORWARD -i $NIC2 -o $LAN -j ACCEPT


# ifconfig -a


#********************************
# allow certain hosts full access
#________________________________

allowHost() {
    $IPT -A FORWARD -i $LAN -s $1 -j ACCEPT 
}

allowHost 192.168.2.10
allowHost 192.168.2.11
allowHost 192.168.2.12
allowHost 192.168.2.13
allowHost 192.168.2.14
allowHost 192.168.2.15

####Extra
$IPT -A FORWARD -d 8.8.8.8 -p tcp -m multiport --dports 53 -j ACCEPT

#********************
# block anything else
#____________________
$IPT -A FORWARD -j LOG -m limit --limit 10/minute --limit-burst 1 --log-prefix "Blocked:"
$IPT -A FORWARD -j DROP

/sbin/modprobe ip_tables
/sbin/modprobe ip_conntrack
/sbin/modprobe ip_conntrack_ftp
/sbin/modprobe ip_nat_ftp
/sbin/modprobe iptable_nat

Topografia de Rede

Responder1

AVISO: LEIA PRIMEIRO ANTES DE EXECUTAR

AVISO LEGAL: Não testado

Pré-requisitos:

  1. Instale o pacote persistente iptables

    sudo apt-get install iptables-persistent

  2. Faça backup de suas regras existentes do iptables:

    sudo iptables-save > ~/iptables-export

    • Restaurar:

      sudo iptables-restore < ~/iptables-export

  3. Libere as antigas regras do iptables:

    sudo iptables -F && sudo iptables -t nat -F && sudo iptables -t mangle -F && sudo iptables -X && sudo iptables -t nat -X && sudo iptables -t mangle -X

Passos:

  1. Adicione uma nova "tabela de rotas" usando este comando do seu terminal para manipular os pacotes de uma das NICs:

    sudo bash -c 'echo "1 rt2" >> /etc/iproute2/rt_tables'

  2. Habilitar encaminhamento ipv4

    sudo sysctl net.ipv4.ip_forward=1
sudo sysctl -p

  3. Adicionar filtro que permite "mascarar"

    sudo iptables -t nat -A PREROUTING -i enp4s5f1 -p tcp --dport 80 -j DNAT --to-destination 192.168.2.90
sudo iptables -t nat -A PREROUTING -i enp4s5f0 -p tcp --dport 80 -j DNAT --to-destination 192.168.2.90


sudo iptables -t nat -A POSTROUTING -o ens2 -j MASQUERADE
sudo netfilter-persistent save
sudo netfilter-persistent reload

  4. Edite o /etc/network/interfacesarquivo e adicione a configuração para a segunda NIC, mas é clarofaça uma cópia do antigo,

    sudo cp /etc/network/interfaces /etc/network/interfaces.bkup:

    iface enp4s5f1 inet static
    address <YOUR_NIC_ADD>/24
    netmask 255.255.255.0
    post-up ip route add 192.168.10.0/24 dev enp4s5f1 src 192.168.10.33 table rt2
    post-up ip route add default via 192.168.10.1 dev enp4s5f1 table rt2
    post-up ip rule add from 192.168.10.33/32 table rt2
    post-up ip rule add to 192.168.10.33/32 table rt2

    • Reinicie o gerenciador de rede:

      sudo  systemctl restart NetworkManager.service

  5. Adicione regras de iptable:

    sudo iptables -t nat -A PREROUTING -i enp4s5f0 -m state --state NEW -m statistic --mode nth
 --every 5 --packet 0 -j DNAT --to-destination 192.168.2.26

sudo iptables -t nat -A PREROUTING -i enp4s5f0 -m state --state NEW -m statistic --mode nth
 --every 4 --packet 0 -j DNAT --to-destination 192.168.2.27

sudo iptables -t nat -A PREROUTING -i enp4s5f0 -m state --state NEW -m statistic --mode nth
 --every 3 --packet 0 -j DNAT --to-destination 192.168.2.28

sudo iptables -t nat -A PREROUTING -i enp4s5f0 -m state --state NEW -m statistic --mode nth
 --every 2 --packet 0 -j DNAT --to-destination 192.168.2.29

sudo iptables -t nat -A PREROUTING -i enp4s5f0 --to-destination 192.168.2.30

=====================================

    sudo iptables -t nat -A PREROUTING -i enp4s5f1 -m state --state NEW -m statistic --mode nth
     --every 5 --packet 0 -j DNAT --to-destination 192.168.2.21

    sudo iptables -t nat -A PREROUTING -i enp4s5f1 -m state --state NEW -m statistic --mode nth
     --every 4 --packet 0 -j DNAT --to-destination 192.168.2.22

    sudo iptables -t nat -A PREROUTING -i enp4s5f1 -m state --state NEW -m statistic --mode nth
     --every 3 --packet 0 -j DNAT --to-destination 192.168.2.23

    sudo iptables -t nat -A PREROUTING -i enp4s5f1 -m state --state NEW -m statistic --mode nth
     --every 2 --packet 0 -j DNAT --to-destination 192.168.2.24

    sudo iptables -t nat -A PREROUTING -i enp4s5f1 -j DNAT --to-destination 192.168.2.25

    sudo netfilter-persistent save
    sudo netfilter-persistent reload

Fonte:

https://scalingo.com/articles/2018/04/20/iptables.html

https://www.webair.com/community/simple-stateful-load-balancer-with-iptables-and-nat/

http://ipset.netfilter.org/iptables-extensions.man.html

https://www.linuxquestions.org/linux/answers/Networking/Spanning_Multiple_DSLs

Como salvar regras do iptables?

https://linuxconfig.org/how-to-restart-network-on-ubuntu-16-04-xenial-xerus-linux

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