vlan

[BevDeLo04397]

I am very nice to network design so please bare with me. I have an Network IP address of 128.112.48.0/22 because my network need to hold 1000+ devices. What would the vlan 10, vlan 20 and vlan 30 but for that. I know 192.168.10.0= vlan 10 and 192.168.20.0 = vlan 20. I have that from examples I've been looking at but I don't know how they get that.

Thanks for the help

[Joseph W. Doherty]

There is no "built-in" relationship between a network prefix and a VLAN.

For example, one could assign 192.168.10.0/20 to vlan 10 and 192.168.20.0/24 to vlan 20 but you could also assign 192.168.10.0/20 to vlan 20 and 192.168.20.0/24 to vlan 10 or assign 192.168.10.0/20 to vlan 123 and 192.168.20.0/24 to vlan 321, etc.

[Jaderson Pessoa]

Hello,

vlan id is used to identify a network in your environment, but the id is not related with network prefix, you can use any prefix between 1 - 4096 in your network if your device support it. But is recommend that each vlan id has your own network prefix.

:)

[luis_cordova]

Hi @BevDeLo04397 

In occasions, a certain internal order is occupied for the assignment of networks or vlan tag.
Something similar happens to the internal order of assigning the first valid ip of a network as a gateway or of occupy vlan 99 as the native vlan.

Assign to network 192.168.10.0 vlan 10 and 192.168.20.0 vlan 20 obeys more to the internal order of who assigned these parameters than to a technical parameter.

As already mentioned, it is possible to assign any vlan tag to any network.
The internal order of this assignment will depend on the network administrator.

Regards

PD: As in many cases, a custom or internal order becomes a policy over time.
Unfortunately, this practice makes it easier for hackers to attack.
Therefore, it is advisable to have your own internal order.

[Georg Pauwen]

Hello,

in order to get three Vlans out of the 128.112.48.0/22 range, you need to go to a /23 mask for one Vlan, and a /24 mask for two others: That would give you:

Vlan X

126.112.48.0/23
126.112.48.1 - 126.112.49.254

Vlan Y

126.112.50.0/24
126.112.50.1 - 126.112.50.254

Vlan Z

126.112.51.0/24
126.112.51.1 - 126.112.51.254