I'm running Ubuntu server v22.04 with 2 NICs - one facing the ISP and one facing the local LAN and is intended to be a media server for the local LAN and the interface between the LAN and WAN.

The NICs:

1. enp0s31f6 - DHCP-ing from ISP equipment with 192.168.1.65 and then out to WAN


2. enp3s0 - static IP 192.168.126.10 and DHCP server for the rest of the LAN network on the 192.168.126.x network.

Goal would be that all devices get a 192.168.126.x address and then have traffic flow to the server 192.168.126.10/192.168.1.65 and then out to the internet.

The server CAN talk to the internet at large and can ping the static LAN IP 192.168.126.10 (itself), but cannot ping workstations on the 192.168.126.x network

Workstations that have pulled a DHCP'ed 192.168.126.x address CAN ping the local network server address 192.168.126.10, but not ISP address 192.168.1.65. These workstations cannot access the internet.

Netplan config:

network:

  version: 2

  ethernets:

    enp0s31f6:

      dhcp4: true

      nameservers:

        addresses: [4.2.2.1,8.8.4.4]

      routes:

        - to: 192.168.1.0/24

          via: 192.168.1.1

      routing-policy:

        - from: 192.168.1.0/24

    enps0:

      addresses: [192.168.126.10/32]

      dhcp4: no

      nameservers:

        addresses: [4.2.2.1,8.8.4.4]

      routes:

        - to: 192.168.126.0/24

          via: 192.168.126.10

        - to: 192.168.1.0/24

          via: 192.168.126.10

      routing-policy:

        - from: 192.168.126.0/24

dhcpd.conf

authoritative;



server-identifier 192.168.126.10;

option domain-name "whatever.local";



shared-network dhcp-server

{

  subnet 192.168.126.0 netmask 255.255.255.0

  {

     option domain-name-servers 1.1.1.1, 8.8.4.4;

     option subnet-mask 255.255.255.0;

     option broadcast-address 192.16.126.255;

     option routers 192.168.126.10;

     option domain-name "whatever.local";

     default-lease-time 14400;

     max-lease-time 20000;

     range 192.168.216.100 192.168.126.250;

  }

}

The DHCP config was copied from an older CentOS box that had been working.

Workstation ipconfig /all results

Connection specific DNS suffix : whatever.local

DHCP Enabled ................. : Yes

Autoconfiguration Enabled .... : Yes

IPv4 Address ................. : 192.168.126.127(Preferred)

Subnet Mask .................. : 255.255.255.0

Default Gateway .............. : 192.168.126.10

DHCP Server .................. : 192.168.126.10

DNS Server ................... : 1.1.1.1

                                 8.8.4.4

DHCP seems to be working, but I just can't seem to get workstation traffic to hit the WAN addresses. Workstations cannot ping Google.com but can access any 192.168.126.10 services (ssh, httpd, etc)

Netplan is completely new to me and I am not a networking guru, nor am I convinced that this is the best setup. But I've been trying to mimic what had previously been working in CentOS.

ufw is disabled (for now)

/proc/sys/et/ipv4/ip_forward is 1

sysctl.conf has net.ipv4.ip_forward=1

I do not have any iptables rules.

Can anyone help me get traffic flowing between these two NICs or set me in a different direction to solve the local LAN to server to WAN issues I'm having?

Thanks in advance!