TP Link Archer C7 Class B Subnet

[AudioEngineer654]

Hey everyone, 

 

So I'm trying to configure my network and wanted to change to a Class B Subnet (255.255.0.0). I've changed my subnet in the LAN section of my router but when I go into DHCP to change the start and end IP addresses from 192.168.0.1 to 192.168.255.255, it tells me that they are out of range. Correct me if I'm wrong, but aren't those IP's the range of a Class B subnet? My default gateway is 192.168.1.1 if that matters. 

 

Thanks for the help!

[Oshino Shinobu]

Class B addresses range from 128.0.x.x to 191.255.x.x. So 192.x.x.x is not a class B address, it is class C.

 

EDIT: Also, is there any particular reason you want to setup a Subnet?

[AudioEngineer654]

Class B addresses range from 128.0.x.x to 191.255.x.x. So 192.x.x.x is not a class B address, it is class C.

Well then. I guess I need to study more. Either way, is that IP range within a Class C subnet? I believe it's a /16 subnet but I had the classes confused. EDIT: Yes. I've got a home lab setup for Cisco cert training and wanted to reserve some IP addresses for the new gear (2x 1841's, 3550, 3560) I.E. 192.168.2.1-2 -> 1841's 192.168.3.1-2 -> 3550 & 3560. etc. 

[Oshino Shinobu]

Well then. I guess I need to study more. Either way, is that IP range within a Class C subnet? I believe it's a /16 subnet but I had the classes confused. 

Class C ranges from 192.0.0.0 to 223.255.255.0. The majority of home networks will just be the default Class C address ranges of 192.168.x.x. The 254 hosts of class C is normally enough for home use. Do you need the increased host count for the network?

 

Everything up to 239.255.255.255 is Class D for multicasting, and anything past that is Class E and reserved for experimental uses. Neither Class D or E have Subnet Masks. 

[Wombo]

Hey everyone, 

 

So I'm trying to configure my network and wanted to change to a Class B Subnet (255.255.0.0). I've changed my subnet in the LAN section of my router but when I go into DHCP to change the start and end IP addresses from 192.168.0.1 to 192.168.255.255, it tells me that they are out of range. Correct me if I'm wrong, but aren't those IP's the range of a Class B subnet? My default gateway is 192.168.1.1 if that matters. 

 

Thanks for the help!

You don't really need to worry about classes of address anymore, they are strictly legacy. They are really only used for educational purposes and legacy support at this point.

 

It does depend on your firmware and the device you are using, however I see a few possible issues/solutions here.

 

First try changing the range to 192.168.0.1 through 192.168.255.254 as 192.168.255.255 would be a broadcast address and may be considered "out of range", depending on firmware.

 

If that doesn't work try changing it to 192.168.0.0 through 192.168.255.255

 

For either of these options ensure the subnet mask is set to either /16 or 255.255.0.0

 

Another possible solution is to use a different subnet such as a part of the RFC 1918 address space of Class B's, ex. 172.16.0.0 through 172.16.255.255 (172.16.0.1 through 172.16.255.254 usable), again with a /16 or 255.255.0.0 subnet mask

 

Some firmware's on devices do NOT like breaking any class boundaries, no matter how legacy the idea may be. However any RFC 1918 address space should work, regardless of subnet, so long as the ranges are configured correctly. Your Cisco devices certainly wouldn't have any issue in doing this, I cannot speak for the TP-Link device tho.