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<> wrote in message
news:db9bcfcf-380d-4787-9a07-...
>I just received IP information for a new Internet connection and they
> did not include the Subnet Mask. How can I figure this address? The
> IP is 63.253.x.x
>
Try...
255.255.255.0

I just received IP information for a new Internet connection and they
did not include the Subnet Mask. How can I figure this address? The
IP is 63.253.x.x

Hey, thanks for the quick response!
I'm having to pre-configure a router for an office in another city.
Is there an exact equation that anyone knows of?
Honestly, I'm afraid to ask the ISP a stupid question but I might just
have to ask them why they didn't supply the Subnet Mask.

On Fri, 25 Jan 2008 10:21:13 -0800 (PST), John Doe
<> wrote:

>Hey, thanks for the quick response!
>I'm having to pre-configure a router for an office in another city.
>Is there an exact equation that anyone knows of?
>Honestly, I'm afraid to ask the ISP a stupid question but I might just
>have to ask them why they didn't supply the Subnet Mask.

Maybe it's not needed.

On Fri, 25 Jan 2008 10:04:46 -0800 (PST),
wrote:

>I just received IP information for a new Internet connection and they
>did not include the Subnet Mask. How can I figure this address? The
>IP is 63.253.x.x

255.255.0.0 covers all the addresses in the 63.253.0.0 network

gb

On Fri, 25 Jan 2008 10:04:46 -0800 (PST),
wrote:

>I just received IP information for a new Internet connection and they
>did not include the Subnet Mask. How can I figure this address? The

..x.x is fairly invalid in most systems.

>IP is 63.253.x.x

Don't ask, tell them they forgot to supply that information.

www.google.com for - subnet calculator

Depends on if you mean exactly 1 address or a small range.

At worst case 255.255.0.0 for
63.253.0.1 - 63.253.255.254
and how much of that the ISP handed out to other users.

Me

On Fri, 25 Jan 2008 10:21:13 -0800 (PST), John Doe
<> wrote:

>Hey, thanks for the quick response!
>I'm having to pre-configure a router for an office in another city.
>Is there an exact equation that anyone knows of?
>Honestly, I'm afraid to ask the ISP a stupid question but I might just
>have to ask them why they didn't supply the Subnet Mask.

The MASK determines what computers are in your "local" network.
Determining the MASK is supposed to be done according to the "class"
of network your on. Some networks allow for configurations of 256 IP
addresses, some allow for 65536, and others in between. You can
create some rather freaky combinations, as the subnet mask is actually
bit-masked in reality. Eg. suppose you specify:

255.255.255.250

Then the only computers that'd be local to yours would be those whose
IP address is the same as yours on the first 3 sections, with the 4th
section being either 0,1,4, or 5. This method would allow for in
theory 4 computers on the local network.... Thus if you did

255.255.255.0 All would be well as long as any of your ISP's has the
same numbers for the first 3 parts of the IP address.... If not, then
most ISP's use a subnet mask of 255.255.0.0 Which allows for a range
of 65536 IP addresses. Thinking about it an ISP with only 256 IP
addresses would seem rather limited, but your ISP could be a small
Dial-up with their own equipment (Extremely rare these days as most
ISP's lease their dial-up lines from other companies....)

On Sun, 27 Jan 2008 17:20:12 -0600, Phat Sam wrote:

>On Fri, 25 Jan 2008 10:21:13 -0800 (PST), John Doe
><> wrote:
>
>>Hey, thanks for the quick response!
>>I'm having to pre-configure a router for an office in another city.
>>Is there an exact equation that anyone knows of?
>>Honestly, I'm afraid to ask the ISP a stupid question but I might just
>>have to ask them why they didn't supply the Subnet Mask.
>
>The MASK determines what computers are in your "local" network.
>Determining the MASK is supposed to be done according to the "class"

Except where just about everybody uses CIDR. Haven't used "class" to
subnet anything for a long time.

<snip>

>create some rather freaky combinations, as the subnet mask is actually
>bit-masked in reality. Eg. suppose you specify:
>
>255.255.255.250

250 is freaky, sensible examples and a URL to a subnet tutorial would be
more useful, better to use .248 or .252.

250 isn't contiguous bits, 11111010 and that's mentioned in the RFC as
not illegal however real life / pratical support and the messy
addressing means it's not used in and to be avoided.

>Then the only computers that'd be local to yours would be those whose
>IP address is the same as yours on the first 3 sections, with the 4th
>section being either 0,1,4, or 5. This method would allow for in

0, 1, 4 and 5 is also odd, from your example.

If you are going to try and explain something about subnetting avoid the
freaky examples.

>theory 4 computers on the local network.... Thus if you did

Why use section in place of the common usage octet?

<snip>

Me