Available range in pfsense not right

sd_read

Please see attached screenshot.

Specifically:

Available range 192.168.3.1 - 192.168.2.255

Why is the end point of the available range a smaller IP address than the start?

pfsense.png_thumb

KOM

You're using an incorrect subnet mask. Assuming you want 192.168.3.1 - 192.168.3.254, you would use a mask of 255.255.255.0 also know as a /24.

Derelict

Correct that in the interface configuration.

NogBadTheBad

Just tried it with an unused interface the calculated values seem wrong with a subnet mask of /31 or /32.

172.16.99.1/32 on OPT4 :-

Subnet 172.16.99.1
Subnet mask 255.255.255.255
Available range 172.16.99.2 - 172.16.99.0

172.16.99.1/31 on OPT4 :-

Subnet 172.16.99.0
Subnet mask 255.255.255.254
Available range 172.16.99.1 - 172.16.99.0

172.16.99.1/30 on OPT4 :-

Subnet 172.16.99.0
Subnet mask 255.255.255.252
Available range 172.16.99.1 - 172.16.99.2

doktornotor

Ugh. /31 or /32 is NOT usable for DHCP. PEBKAC.

NogBadTheBad

@doktornotor:

Ugh. /31 or /32 is NOT usable for DHCP. PEBKAC.

I know it's not usable ;D

johnpoz

Welcome back dok! That is the wit I am talking about ;)

KOM

Ugh. /31 or /32 is NOT usable for DHCP. PEBKAC.

JHC I think I've seen a ghost :o

doktornotor

@NogBadTheBad:

@doktornotor:

Ugh. /31 or /32 is NOT usable for DHCP. PEBKAC.

I know it's not usable ;D

Doc, it hurts when I do this… So don't do that. ;D

Eh, I mean, by all means submit a pull request to fix this cosmetic issue with "miscalculation" (not that I could imagine how'd you fix it beyond completely disabling the enable DHCP server checkbox until people fix their subnet, which in turn would only produce another batch of posts about "cannot enable DHCP server no matter what… t3h bug!!!" But why'd anyone knowingly set up a point-to-point subnet (let alone a single host) and try to run DHCP on it? ???

Now, will someone fix my DHCP relay? :'(

JKnott

Ugh. /31 or /32 is NOT usable for DHCP. PEBKAC.

DHCP requires use of the broadcast address,which means the smallest usable subnet is a /30, which provides network address, broadcast address and 2 host addresses. One of those 2 has to be for the server or agent. A /31 provides only 2 host addresses and is used for point to point links. A /32 means only the interface and nothing beyond it.

NogBadTheBad

LOL I was just pointing out the calculation was wrong, I wasn't even the OP.

All my subnets are /24 or /64 :)

doktornotor

Yeah, it's wrong because it makes no sense. See https://redmine.pfsense.org/issues/6930

sd_read

Thank you for your help.

That fixed my problem.