Does pfsense support /31 bit mask?

[coxhaus]

This is more of a curiosity.  I have pfsense connected to my Cisco layer 3 switch using a /30 bit mask.  I wonder if I can use a /31 bit mask?

[bingo600]

@coxhaus:

This is more of a curiosity.  I have pfsense connected to my Cisco layer 3 switch using a /30 bit mask.  I wonder if I can use a /31 bit mask?

An /30 IP network (takes up 4 addresses) consists of :

0: Net address (the lowest)  - MUST HAVE
1: device1  (one end of the ip link)
2: device2  (other end of the ip link)
3: Broadcast adress (the highest) - MUST HAVE

A /31 IP network (takes up 2 addresses)  consists of :

0: Net address (the lowest)  - MUST HAVE
2: Broadcast adress (the highest) - MUST HAVE

Technically it should be "legal" , but how many devices can you connect within that IP Network

/Bingo

[coxhaus]

In a point to point network you don't need a broadcast IP.  I was thinking of trying it if pfsense supported it.  I am changing out my layer 3 switch for another model.

[jimp]

Yes, and it has for a long time:

https://redmine.pfsense.org/issues/4190

[bingo600]

@coxhaus:

In a point to point network you don't need a broadcast IP.  I was thinking of trying it if pfsense supported it.  I am changing out my layer 3 switch for another model.

Whoopzz  :-[  - Did not know RFC 3021

Thanx for making me learn something new today  ;)

/Bingo

[Harvy66]

@bingo600:

@coxhaus:

In a point to point network you don't need a broadcast IP.  I was thinking of trying it if pfsense supported it.  I am changing out my layer 3 switch for another model.

Whoopzz  :-[  - Did not know RFC 3021

Thanx for making me learn something new today  ;)

/Bingo
[/quote]

Been there, done that. I love learning.

[coxhaus]

Me too.  I just learned about it recently.  I thought I might try it.