Panel Server IP address limitations?

sesa125184_brid · ‎2024-03-15

A customer has provided an address of 105.193.211.255 to assign as the IP of a PAS. I am aware that in some instances this is not possible, as x.x.x.255 can be reserved as a broadcast address.

For example, 105.193.211.0/255.255.255.0

The network identifier would be 105.193.211.0
The broadcast address would be 105.193.211.255
Valid (or usable) ip addresses would be 105.193.211.1 to 105.193.211.254

However in an expanded network (Class A/B), I was under the assumption that this should be possible.
For example, 105.193.211.0/255.255.0.0

The network identifier would be 105.193.0.0
The broadcast address would be 105.193.255.255
Valid (or usable) ip addresses would be 105.193.0.1 to 105.193.255.254

When I am testing this on a PAS, it fails to save an IPV4 address ending in .255 regardless of the subnet. Am I missing something obvious? Or misunderstanding the capabilities here? Thanks.

Thierry_Baudard · ‎2024-03-20

Hello,

As you mentioned, an all IPV4@ ended terminated by 255- in a /16 or larger subnet should not be prohibited .
But today the control of the value entered is simplified and all IP@ ending in 255 are prohibited regardless of the value of the mask.
The workaround today is to set another IP@ not terminated with 255. This should be possible due to the larger number of IP@s available in a class A/B subnet.

Thierry BAUDARD
EccoStruxure Customer support

See Answer In Context

Vivian_Wang · ‎2024-03-19

I am no PAS expert, but I suspect 255 is reserved for historical reason https://www.se.com/us/en/faqs/FA222364/

wasabi · ‎2024-03-19

IP Address: 105.193.0.0/16
Network Address: 105.193.0.0
Usable Host IP Range: 105.193.0.1 - 105.193.255.254
Broadcast Address: 105.193.255.255
Total Number of Hosts: 65,536
Number of Usable Hosts: 65,534
Subnet Mask: 255.255.0.0

In theory, the PAS should be able to recognise /16 and allow IP assignment within any of the Usable Host IP range as above.. however seem like any IP ending with .255 is given this error.

Guillaume_Evrard · ‎2024-03-19

hello,

This is what I remember 0 is the network address and 255 is the brodcast address if you have /24 subnet.

Thierry_Baudard · ‎2024-03-20

Hello,

As you mentioned, an all IPV4@ ended terminated by 255- in a /16 or larger subnet should not be prohibited .
But today the control of the value entered is simplified and all IP@ ending in 255 are prohibited regardless of the value of the mask.
The workaround today is to set another IP@ not terminated with 255. This should be possible due to the larger number of IP@s available in a class A/B subnet.

Thierry BAUDARD
EccoStruxure Customer support

sesa125184_brid · ‎2024-03-20

Thanks for the response. This is what I was expecting.