How to make two subnets visible to each other on zyxel usg60?

Question

Computer networks

There was a problem with each subnet seeing each other, despite the fact that they are all physically connected through the same switch.

I’ll explain the whole point in more detail: there is a main zyxel usg60 router with IP 192.168.0.2 from it a cable goes to a gigabit switch (all ports of the switch are gigabit Tp-link Tl-sg 1008 mp ) from this switch to HP 1910-48 switches (they, like me they explained, they initially set it up and didn’t set it up in any way, if I understand correctly, they simply work like an unmanaged switch) all computers and routers are already connected to them.

Since there were not enough IP addresses at one time, we decided that just one of the routers connected to the switch set up another subnet 192.168.15.1 (the router was connected via WAN) and everyone who connects to it via WIFI receives an IP from the 15th subnet themselves they see the null subnet but anyone on the 192.168.0.(network) subnet does not see them.

The essence of the problem is to make it so that everyone who is in subnet 0 and subnet 15 can see each other

Answer 1

For starters, stop calling a switch (aka switch) a hub .
Why is there a TL-SG1008MP in this chain? It looks like it can and should be removed.
Now there are two ways:

1. We completely save the current addressing:
   
   • On the USG60, we create a VLAN with an interface type of "internal" and a VLAN ID of our choice (for example, 15). The zone and the base interface are set according to the settings of the currently active port. Most likely it will be LAN1 and lan1, respectively. In the future, if there is a need or desire to more flexibly configure routing and security policies, then all this can be easily changed.
     On the newly created interface, we prescribe an IP address from the 192.168.15.0/24 subnet (any unoccupied one) and configure the DHCP server. But in order for everything to go completely unnoticed by users, it is better to register 192.168.15.1.
     
   • We go to the HP switch through which the unnamed Wi-Fi router is connected, and first we determine the port numbers to which the USG60 (GW1 port) and Wi-Fi (GW2 port) are connected.
     As soon as we receive this information, we go into the switch settings and create a VLAN with the same ID that was registered on the USG60. Most likely this is done through VLANS → VLAN Membership → Add VLAN → (enter VLAN ID) → Add. From the previous step, we make ports GW1 and GW2 members of this VLAN and apply the settings.
     Since our Wi-Fi most likely does not know how to VLAN, in the switch settings we find VLAN Port Config and for the GW2 port we prescribe the PVID of our new VLAN.
     
   • Turn off DHCP on Wi-Fi. If IP 192.168.15.1 was registered on USG60, then here we change it to any other free one. And only after that we plug the cable from the WAN to the LAN port - our router becomes just an access point, and USG60 is responsible for issuing addresses and routing between subnets .
     
   • If there are devices with static IP addresses on the 192.168.15.0/24 subnet and you did not assign USG60 the address 192.168.15.1, then on these devices you will need to manually change the default gateway and possibly DNS to the address that was chosen for USG60.
     
   
   
2. If you do not have devices with static IP addresses or there are not many of them, you can make it easier and combine everything into one subnet (although the recommendations are just the opposite, but we will leave them out of the brackets).
   We combine all devices into one subnet:
   
   • On the USG60, go to the interface settings (most likely it will be the lan1 interface) and change the subnet mask. The current mask 255.255.255.0 or /24 gives us 254 addresses. The mask 255.255.254.0 or /23 will already give 510, the mask 255.255.252.0 go /22 - 1022 and so on in powers of two (−2 addresses). In the same place, in the DHCP parameters, we change the range of IP addresses available to clients.
     Open the IP address calculator and calculate for yourself which one suits you best. I don’t recommend setting 255.255.0.0 right away, as advised in the next answer, because if you need to split the network (for example, allocate a DMZ), then it will not be so convenient.
     
   • On Wi-Fi, turn off DHCP and change the IP address to any free one in the new range, taking into account the new mask. We poke the cable from the WAN to the LAN port - our router becomes just an access point, and the USG60 is responsible for issuing addresses.
     
   • If there are devices with static IP addresses on the network, then on these devices you will need to manually change the subnet mask , and for devices with addresses from 192.168.15.0/24, completely register the new settings. However, if you have chosen a mask of /20 or less, then only change the subnet mask.
     
   
   

Answer 2

You can change the mask on Zyxel to 255.255.0.0 - it should be enough.
And use the WiFi router as a switch (i.e. do not use the WAN port and disable DHCP). Then all WiFi clients will receive the ip address that DHCP gives out on Zyxel.