My firewall, an iptables Linux box only has one Ethernet port.
My network topology is pretty simple and looks something like this:
ISP (Port Gi 1/1) -> Switch <-Firewall on Port Gi 1/2
^
|
Other devices Gi 1/3 - Gi 1/48
On my firewall the eth0 interface can have both a DHCP address (from ISP) and a private 192.168.x.x address on the same eth0 interface (as a gateway/dhcp server).
The NATing from my private network to my ISP works and all connected devices can access the internet. However, I'd like to separate the two networks because right now nothing is stopping my other devices from trying to request an IP from my ISP which they shouldn't be able to do.
How could I separate and have my firewall NAT between the two networks with my Dell 3048-ON switch?
P.S. I know it may be more simple to buy an extra network card for my firewall but I rather not have to. Thanks in advance for help on this
My switch has a basic configuration but here it is anyway:
Current Configuration ...
! Version 9.13(0.0)
! Last configuration change at Tue Jan 16 03:00:13 2018 by default
!
boot system stack-unit 1 default system: A:
!
hostname DellEMC
!
protocol lldp
!
redundancy auto-synchronize full
!
stack-unit 1 provision S3048-ON
!
interface GigabitEthernet 1/1
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/2
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/3
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/4
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/5
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/6
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/7
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/8
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/9
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/10
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/11
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/12
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/13
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/14
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/15
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/16
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/17
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/18
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/19
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/20
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/21
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/22
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/23
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/24
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/25
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/26
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/27
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/28
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/29
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/30
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/31
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/32
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/33
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/34
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/35
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/36
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/37
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/38
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/39
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/40
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/41
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/42
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/43
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/44
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/45
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/46
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/47
no ip address
switchport
no shutdown
!
interface GigabitEthernet 1/48
no ip address
switchport
no shutdown
!
interface TenGigabitEthernet 1/49
no ip address
shutdown
!
interface TenGigabitEthernet 1/50
no ip address
shutdown
!
interface TenGigabitEthernet 1/51
no ip address
shutdown
!
interface TenGigabitEthernet 1/52
no ip address
shutdown
!
interface ManagementEthernet 1/1
no ip address
no shutdown
!
interface ManagementEthernet 2/1
no shutdown
!
interface ManagementEthernet 3/1
no shutdown
!
interface ManagementEthernet 4/1
no shutdown
!
interface ManagementEthernet 5/1
no shutdown
!
interface ManagementEthernet 6/1
no shutdown
!
interface Vlan 1
!untagged GigabitEthernet 1/1-1/48
!
line console 0
line vty 0
line vty 1
line vty 2
line vty 3
line vty 4
line vty 5
line vty 6
line vty 7
line vty 8
line vty 9
!
reload-type
boot-type normal-reload
config-scr-download enable
!
end
