2

I have a gateway with two ISP connected to eth0 and eth2. There is also a eth1 with local network. I'm trying to group some services in one interface and some in the second:

incoming traffic
1    eth0: 22 sshd, 80 http, 8080 http
2    eth2: 22 sshd

outgoing traffic 
3    eth2: 22 ssh, 25 smtp, 80 http, 110 pop3, 443 https, 587 smtp
4    eth0: the rest of the ports

I managed to reroute the traffic in points 1,3,4 using iptable, iproute2 with fwmark. Here is interface setup:

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
        address aaa.aaa.aaa.90
        netmask 255.255.255.248
        gateway aaa.aaa.aaa.89

auto eth2
iface eth2 inet static
        address bbb.bbb.bbb.137
        netmask 255.255.255.192
        pre-up /usr/local/bin/firewall.sh

auto br0
iface br0 inet static
        address 192.168.1.1
        netmask 255.255.0.0
        bridge-ports eth1
        post-up ifconfig eth1 0.0.0.0 promisc up

Here is ip route and ip rules:

ip route show table main
aaa.aaa.aaa.88/29 dev eth0  proto kernel  scope link  src aaa.aaa.aaa.90
bbb.bbb.bbb.128/26 dev eth2  proto kernel  scope link  src bbb.bbb.bbb.137
192.168.0.0/16 dev br0  proto kernel  scope link  src 192.168.1.1
default via aaa.aaa.aaa.89 dev eth0

ip route show table 4
aaa.aaa.aaa.88/29 dev eth0  proto kernel  scope link  src aaa.aaa.aaa.90
bbb.bbb.bbb.128/26 dev eth2  proto kernel  scope link  src bbb.bbb.bbb.137
192.168.0.0/16 dev br0  proto kernel  scope link  src 192.168.1.1
default via bbb.bbb.bbb.129 dev eth2

0:      from all lookup 255
32765:  from all fwmark 0x4 lookup 4
32766:  from all lookup main
32767:  from all lookup default

And iptables:

    iptables -F
    iptables -t nat -F
    iptables -t mangle -F
    iptables -P INPUT DROP


    iptables -A INPUT -i lo -j ACCEPT
    iptables -A INPUT -p udp --sport 68 --dport 67 -m physdev --physdev-in tap1 -j DROP
    iptables -A INPUT -i eth1 -j ACCEPT
    iptables -A INPUT -i eth2 -j ACCEPT
    iptables -A INPUT -i br0 -j ACCEPT
    iptables -A INPUT -p icmp -j ACCEPT
    iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
    iptables -A INPUT -p tcp --dport 22 -s 0/0 -j ACCEPT
    iptables -t mangle -A PREROUTING -p tcp --dport 22 -d bbb.bbb.bbb.137 -j MARK --set-mark 4
    iptables -t mangle -A PREROUTING -p tcp --dport 25 -s 192.168.0.0/16 -j MARK --set-mark 4
    iptables -t mangle -A PREROUTING -p tcp --dport 80 -s 192.168.0.0/16 -j MARK --set-mark 4
    iptables -t mangle -A PREROUTING -p tcp --dport 8080 -s 192.168.0.0/16 -j MARK --set-mark 4
    iptables -t mangle -A PREROUTING -p tcp --dport 110 -s 192.168.0.0/16 -j MARK --set-mark 4
    iptables -t mangle -A PREROUTING -p tcp --dport 443 -s 192.168.0.0/16 -j MARK --set-mark 4
    iptables -t mangle -A PREROUTING -p tcp --dport 587 -s 192.168.0.0/16 -j MARK --set-mark 4
    iptables -t nat -A PREROUTING -p tcp -d aaa.aaa.aaa.90 --dport 80 -j DNAT --to-destination 192.168.1.252:80

    iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to-source aaa.aaa.aaa.90
    iptables -t nat -A POSTROUTING -o eth2 -j SNAT --to-source bbb.bbb.bbb.137

    iptables -t nat -A POSTROUTING -s 192.168.1.0/16 -j MASQUERADE

I cannot access eth2 bbb.bbb.bbb.137:22 from outside even when I listen to all interfaces:

tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN     3111/sshd

Does anyone issued any instability in performance using fwmark iproute2? eth2 provider is much faster then eth0 but using eth2 I experienced some stalls - like there were some ISP problems but there is no problem with internet service provider - checked with second router at the same time? Could some one please point me in right direction. THX

  • I've once tried to get routing to work with fwmarks but failed, I didn't spend too much time on it though – wurtel Jun 26 '15 at 7:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.