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lardboy
30-07-2006, 10:23
My subnet mask is normally 255.255.255.0 and on every network I have used this has been the case.

However for some reason my subnet mask on my current connection to ntl is 255.255.252.0

Is this a problem? :( :dunce:
Matthew
30-07-2006, 10:37
I noticed this on my Gran's connection and is has not caused her any problems.
Toto
30-07-2006, 11:27
My subnet mask is normally 255.255.255.0 and on every network I have used this has been the case.

However for some reason my subnet mask on my current connection to ntl is 255.255.252.0

Is this a problem? :( :dunce:

As long as your surfing ok, you should be fine :)
Paul
30-07-2006, 11:49
My subnet mask is normally 255.255.255.0 and on every network I have used this has been the case.

However for some reason my subnet mask on my current connection to ntl is 255.255.252.0

Is this a problem? :( :dunce:Nope - it's fine, just a change in the way ntl are allocating ip blocks on the ubr's.
Enuff
30-07-2006, 12:20
Don't you just love the subject of subnet masking :confused:
SnoopZ
30-07-2006, 12:32
Mines still 255.255.255.0.
Enuff
30-07-2006, 12:51
Mines still 255.255.255.0.Same here.
lardboy
30-07-2006, 13:21
Thanks for the reply I never could get my head around subnets I always just use 255.255.255.0 :confused:
Graham M
30-07-2006, 13:23
255.255.255.0 is for class C (Private Networks) Generally for a home network with Private IP addressing
Paul
30-07-2006, 13:46
Mines still 255.255.255.0.Not every area has changed.
greencreeper
30-07-2006, 18:05
Don't you just love the subject of subnet masking :confused:
Perhaps Paul could explain it all to us :D
SimpleSimon
30-07-2006, 22:13
Oh the joys of CIDR.

And mine is 255.255.252.0
darkone338
30-07-2006, 23:36
255.255.255.0 is for class C (Private Networks) Generally for a home network with Private IP addressing

thats wrong on so many levels.

Class C (which does not refer to private networks) are in no way just confined to a home network with private ip addresses.
kronas
31-07-2006, 00:13
yep, mines changed too..

255.255.252.0

yes we need an explaination on what this means....

To increase the number of IP's on the subnet, change the subnet mask on *all* hosts to 255.255.252.0, while still using the same IP addresses. Make sure every single host gets changed, or you will have communication issues. With a 255.255.252.0 mask, your network will now range from 192.168.0.0 through 192.168.3.254.

http://www.askdavetaylor.com/how_does_a_subnet_work.html
TheNorm
31-07-2006, 08:45
255.255.252.0 in Cambridge.

When will we start using IPv6?

INTERNET
Cable/DSL : CONNECTED
WAN IP: 81.98.xxx.xxx
Subnet Mask: 255.255.252.0
Gateway IP: 81.98.xxx.xxx
DNS: 194.168.xxx.xxx
Secondary DNS: 194.168.xxx.xxx
Graham M
31-07-2006, 09:06
When will we start using IPv6?

Dont expect to see it for a good few years yet
tweetiepooh
31-07-2006, 17:36
The subnet mask just defines where the break between the network and host part of the address is.

Take a typical home router. (LAN side)
LAN IP = 192.168.1.1
Mask = 255.255.255.0

This means the network part is
192.168.1 and the host is .1

Now 192.168.1.0 is the network address and 192.168.1.255 is the broadcast address so you can have 254 hosts 1-254.

Now lets say the you have some 300 hosts on you lan that you need as a single network, what you can do is borrow bits from the next left octet to use as host addresses, we only need 1 bit.

Now netmast is 255.255.253.0

Network address is now 192.168.0.0 and the broadcast is still 192.168.1.255. Hosts now range from 192.168.0.1 to 192.168.1.254 giving 511 hosts. The router can still remain at 192.168.1.1. (Note that in this case 192.168.0.255 and 192.168.1.0 are now valid host addresses but I guess that best practice would not use them if possible.).

As an aside you can write addresses as 192.168.1.1/23 to indicate where the network/host break is.

Also the netmask will affect other networks in the range so you get the next block as 192.168.2.0-192.168.3.255; 192.168.4.0-192.168.5.255 upto 192.168.254.0-192.168.255.255.
JohnHorb
31-07-2006, 18:23
The subnet mask just defines where the break between the network and host part of the address is.

Take a typical home router. (LAN side)
LAN IP = 192.168.1.1
Mask = 255.255.255.0

This means the network part is
192.168.1 and the host is .1

Now 192.168.1.0 is the network address and 192.168.1.255 is the broadcast address so you can have 254 hosts 1-254.

Now lets say the you have some 300 hosts on you lan that you need as a single network, what you can do is borrow bits from the next left octet to use as host addresses, we only need 1 bit.

Now netmast is 255.255.253.0

Network address is now 192.168.0.0 and the broadcast is still 192.168.1.255. Hosts now range from 192.168.0.1 to 192.168.1.254 giving 511 hosts. The router can still remain at 192.168.1.1. (Note that in this case 192.168.0.255 and 192.168.1.0 are now valid host addresses but I guess that best practice would not use them if possible.).

As an aside you can write addresses as 192.168.1.1/23 to indicate where the network/host break is.

Also the netmask will affect other networks in the range so you get the next block as 192.168.2.0-192.168.3.255; 192.168.4.0-192.168.5.255 upto 192.168.254.0-192.168.255.255.

255-1 bit = 254, i.e.
255.255.254.0