Setting up a LAN subnet involves configuring network settings for connected devices.
Setting up a LAN subnet involves configuring network settings for connected devices.
I'm trying to form four smaller networks from my local area network, but I encountered a problem I'm struggling to understand. Internet Service Provider: Century Link Modem: Zyxel C3000Z Router's Gateway IP address: 192.168.0.1 LAN Subnet Mask: /24 (255.255.255.0) My goal was to split my LAN into four equal-sized networks. This is the first time I've attempted this, yet I'm confident the calculations are correct. The expected new subnet would be /26 (255.255.255.192). With a block size of 64, the plan is:
- First subnet: 192.168.0.0/26
- Second subnet: 192.168.0.64/26
- Third subnet: 192.168.0.128/26
- Fourth subnet: 192.168.0.192/26
I adjusted my router settings to apply the second subnet exactly as shown above, avoiding changes for all at once. I connected my device to the correct IP for that subnet and managed to access the router. From there, I could log in and make adjustments. However, I couldn't reach any other devices on the network—seemingly because I was the only one on that subnet. Accessing the WAN was completely blocked. Only my router at 192.168.0.1 was reachable.
It appears my subnet is able to communicate with the router's gateway (192.168.0.1), but it doesn't seem to know how to use the router to connect to the wider network. This seems like a tricky issue, possibly due to complex routing rules. I've tried everything possible in the last few hours without success.
Someone might have insight into this subnet math—since by default the router's gateway is 192.168.0.1, and my first subnet calculation included that address, it feels contradictory that the router should be outside its own subnet. Also, when I tried to create the first subnet with /26, the router reported a conflict error because an address like that was already in use. So I couldn't build that first network.
Despite this, the overall plan is clear: divide the main network into four equal parts. I'm unsure if my approach aligns perfectly, but I'm hoping someone can clarify what's going wrong.
I'm organizing your network by separating devices into different subnets. The primary computers and laptops are on the first subnet, while IoT devices go on the second. The final two will be added later. You're wondering if each new subnet needs its own route to connect externally—yes, that should be configured in your router, even if it doesn't appear to do so automatically.
Thanks for using the online calculator—it's a really useful tool!
Are your routers and firewalls capable of handling VLANs? Do they offer a way to restrict traffic between different subnets? Additionally, your switches and Wi-Fi access points must support VLAN awareness for this setup to function properly (unless all connected devices are on one subnet, which would eliminate the need for VLAN-aware switches but still require VLAN-capable Wi-Fi APs). Essentially, if you can't enforce firewall rules between subnets or connect devices across them without a dedicated VLAN hardware solution, this approach won't deliver real security. Subnets can communicate unless a firewall blocks their traffic.