Hello, guys! How are you?
I'd like to ask for help with servers and networking.
In my network, I have 2 blocks: 192.168.1.0/24 and 192.168.2.0/24.
The 1st network is OK: it's connected to the Internet and the servers/clients have access to "anything" in the web. But, I'm facing problems with my 2nd network.
I have 2 servers (master/slave) that connect the 1st network with the 2nd one, but I can't get a default route/gateway from 192.168.1.0/24 to 192.168.2.0/24.
For both servers, here is my network interface's setting:
Code:
auto lo
iface lo inet loopback
# First Network
auto enp0s3
iface enp0s3 inet static
network 192.168.1.0
gateway 192.168.1.1
broadcast 192.168.1.255
netmask 255.255.255.0
address 192.168.1.181 # Secondary server's address is 192.168.1.182
# Second network
auto enp0s8
iface enp0s8 inet static
network 192.168.2.0
#gateway 192.168.2.1
broadcast 192.168.2.255
netmask 255.255.255.0
address 192.168.2.1 # Secondary server's address is 192.168.2.2
Here is my Primary DHCP server's config (the Secondary DHCP server is basicly the same thing):
Code:
authoritative;
ddns-update-style interim;
option domain-name "mynetwork.local";
option domain-name-servers ns1.mynetwork.local, ns2.mynetwork.local, 192.168.2.1, 192.168.2.2;
default-lease-time 600;
max-lease-time 7200;
log-facility local7;
failover peer "DHCP-FAILOVER" {
primary;
address 192.168.2.1;
port 647;
peer address 192.168.2.2;
peer port 647;
max-response-delay 30;
max-unacked-updates 10;
load balance max seconds 3;
mclt 1800;
split 128;
}
subnet 192.168.2.0 netmask 255.255.255.0 {
option routers 192.168.2.1, 192.168.2.2;
option subnet-mask 255.255.255.0;
option domain-name "mynetwork.local";
option domain-name-servers 192.168.2.1, 192.168.2.2;
option netbios-dd-server 192.168.2.1, 192.168.2.2;
option netbios-name-servers 192.168.2.1, 192.168.2.2;
option netbios-node-type 8;
option nis-domain "mynetwork.local";
option nis-servers 192.168.2.1, 192.168.2.2;
option nisplus-domain "mynetwork.local";
option nisplus-servers 192.168.2.1, 192.168.2.2;
option ntp-servers 192.168.2.1, 192.168.2.2;
option time-offset -18000;
pool {
failover peer "DHCP-FAILOVER";
range 192.168.2.3 192.168.2.254;
}
}
And I have this firewall script:
Code:
#!/bin/bash
modprobe iptable_nat
modprobe iptable_filter
modprobe iptable_mangle
modprobe ipt_MASQUERADE
modprobe ip_tables
modprobe nf_conntrack
modprobe nf_conntrack_ipv4
modprobe nf_nat
modprobe nf_tables
modprobe nf_tables_ipv4
modprobe nft_masq
modprobe nft_masq_ipv4
modprobe nft_nat
modprobe nft_redir
modprobe nft_redir_ipv4
iptables -t filter -F
iptables -t mangle -F
iptables -t nat -F
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT
EXTERNAL_NETWORK=192.168.1.0 # My 1st network
EXTERNAL_INTERFACE=enp0s3 # Interface connected to 192.168.1.0/24
INTERNAL_NETWORK=192.168.2.0 # My 2nd network
INTERNAL_INTERFACE=enp0s8 # Interface connected to 192.168.2.0/24
# Getting hostname to set the variable "SRV_IP_ADDR"
[[ $(hostname) = master ]] && SRV_IP_ADDR=192.168.2.1 || SRV_IP_ADDR=192.168.2.2
echo 1 > /proc/sys/net/ipv4/ip_forward
iptables -t nat -A POSTROUTING -o $EXTERNAL_INTERFACE -j MASQUERADE
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -i $EXTERNAL_INTERFACE -j ACCEPT # Interface enp0s3
iptables -A OUTPUT -o $EXTERNAL_INTERFACE -j ACCEPT
iptables -A FORWARD -i $EXTERNAL_INTERFACE -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
# Accepting SSH connections
iptables -A INPUT -i $EXTERNAL_INTERFACE -p tcp --dport 1024 -j ACCEPT
iptables -A INPUT -s $EXTERNAL_NETWORK/24 -p tcp --dport 1024 -j ACCEPT
# If a package goes to the internet (external network), it must return to the internal network
iptables -A FORWARD -d $INTERNAL_NETWORK/24 -p tcp -j ACCEPT
iptables -A FORWARD -s $INTERNAL_NETWORK/24 -p tcp -j ACCEPT
# Accepting WWW, WWWS, DHCP and DNS connections/queries
iptables -A FORWARD -s $SRV_IP_ADDR -m multiport -p tcp --dport 80,443 -j ACCEPT
iptables -A FORWARD -d $SRV_IP_ADDR -m multiport -p tcp --sport 80,443 -j ACCEPT
# These 2 lines bellow are for TCP
iptables -A FORWARD -s $INTERNAL_NETWORK/24 -m multiport -p tcp --dport 53,67 -j ACCEPT
iptables -A FORWARD -d $INTERNAL_NETWORK/24 -m multiport -p tcp --sport 53,67 -j ACCEPT
# These 2 lines bellow are for UDP
iptables -A FORWARD -s $INTERNAL_NETWORK/24 -m multiport -p udp --dport 53,67 -j ACCEPT
iptables -A FORWARD -d $INTERNAL_NETWORK/24 -m multiport -p udp --sport 53,67 -j ACCEPT
What can I do to add a default route to my 2nd network?
I am asking about default route, because I can't install Debian Linux into clients located on 192.168.2.0/24 (It says that are no default route and it fails to set a mirror, because it seems to be a unreachable network). Or in the Windows clients, I need to set the 1st network DNS/gateway (192.168.1.1) to have access to internet.
What can I do?
Thank you for your attention.