I'm completely new to networking, so can anyone help me understand why the below can actually work?

Originally,
inet 10.33.18.6 netmask ff000000 broadcast 10.0.0.0

After doing ifconfig netmask 255.255.248.0,
inet 10.33.18.6 netmask fffff800 broadcast 10.33.16.0

What it's supposed to have,
inet 10.33.18.6 netmask fffff800 broadcast 10.33.23.255

The broadcast IP didn't changed to 10.33.23.255 as calculated but it still works normally even though the broadcast IP is 10.33.16.0.

Tried a subnet calculator & it seems that I should get 10.33.23.255 as broadcasting IP while 10.33.16.0 is the subnet ID.

I don't know where to start.
May depend on the version of solaris.
Start with man ipconfig and sun site for docs.

Might try this as example.

ifconfig hme0:1 10.192.2.70 netmask + broadcast + up

use your nic and ip in place.

I read it wrong and answer it wrong too. So get off my case you peanut.

"Originally,
inet 10.33.18.6 netmask ff000000 broadcast 10.0.0.0

That is not correct. Broadcast is 10.255.255.255 not 10.0.0.0 which is the subnet id.

"inet 10.33.18.6 netmask fffff800 broadcast 10.33.16.0"

How can x.x.18.x have a different subnet for broadcast x.x.16.x?

Given 10.33.18.6 with mask 255.255.248.0 you get broadcast of 10.33.18.7 not 10.33.16.0 according to an online subnet calculator.

You continue to mix subnets x.x.y.x with x.x.z.x

All of your numbers are wacky. Appears you are mixing subnetting with supernetting while forgetting the basic rule of you lose top and bottom of a subnet [host and broadcast] any time you subnet.

Imagine the power if you knew how to internet search

Thanks to jefro & wanderer for replying.

Will read up some docs as recommended.

Wanderer,
I too am puzzled by why it's broadcasting to the subnet ID instead of the intended IP. Is there any reason why it ends up with subnet ID instead of IP?

Did checked with online subnet calculators & it all yields 10.33.23.255 for broadcasting IP & 10.33.16.0 as subnet ID.

IIRC, as long as you've 255 with your net mask, it'll yield the same number for the broadcast IP - eg,
10.33.16.5 netmask 255.255.255.0 = 10.33.16.X
10.33.16.5 netmask 255.255.0.0 = 10.33.X.X
10.33.16.5 netmask 255.0.0.0 = 10.X.X.X
Please correct me if I'm wrong.

Why do you think 10.33.16.255, 10.33.255.255 etc are the same broadcast id? They aren't. Is 10.33.16.0 and 10.33.0.0 the same? of course not. so why 10.33.16.255, 10.33.255.255 the same?

Sorry I have no idea what you are talking about concerning your question.

Imagine the power if you knew how to internet search

Hi Wanderer,
Thanks for the response. Found out the problem with my networking. OS defaults. SunOS 4.1.4 defaults broadcasting IP to 0 instead of 255,
broadcasting IP = 10.33.16.0
network ID = 10.33.16.255

In this case, it's a mix of supernetting & subnetting, thus it gives 10.33.16.0 as the broadcasting IP & 10.33.23.255 as network ID, a reverse of current online netmasking calculators.

I'm puzzled by why it works when it's broadcasting to the network ID instead of broadcasting IP. Why did 10.33.16.0 works in this case when it should be 10.33.23.255?

Our current setup,
Netmasking 10.33.18.X with 255.255.248.0 to yield hosts from 10.33.16.0 to 10.33.23.255.