bcc: Kevin Cullimore)
Subject: Re: Mask in L3 Packet [7:29182]
If you think about this logically, every IP address in your networkor
the Internet is unique, regardless of mask, so why send the mask? The
mask only becomes relevant locally.
Symon
---
> In the local configuration of ever
12/20/01, steve skinner wrote:
> >go on then pris..
> >
> >you have wetted my appetite where is the the subnet mask kept
if it isnt
> >in the ip packet ?
> >
> >
> > >From: "Priscilla Oppenheimer"
> > >Reply-To: "Pris
imer"
> >Reply-To: "Priscilla Oppenheimer"
> >To: [EMAIL PROTECTED]
> >Subject: Re: Mask in L3 Packet [7:29182]
> >Date: Fri, 14 Dec 2001 13:42:36 -0500
> >
> >From its own local config. The mask isn't in the IP packet, which does
> >
>Steve,
>
>According to RFC-791 (ftp://ftp.isi.edu/in-notes/rfc791.txt), all that is
>contained in the IP header with respect to addresses is the source address
>and the destination address, both 32 bit fields. The routers have the task
>of figuring out where to send things based on the routing t
where is the the subnet mask kept if it isnt
in the ip packet ?
>From: "Priscilla Oppenheimer"
>Reply-To: "Priscilla Oppenheimer"
>To: [EMAIL PROTECTED]
>Subject: Re: Mask in L3 Packet [7:29182]
>Date: Fri, 14 Dec 2001 13:42:36 -0500
>
>From its
go on then pris..
you have wetted my appetite where is the the subnet mask kept if it isnt
in the ip packet ?
>From: "Priscilla Oppenheimer"
>Reply-To: "Priscilla Oppenheimer"
>To: [EMAIL PROTECTED]
>Subject: Re: Mask in L3 Packet [7:29182]
>Da
If the sending host strips the netmask how does the gateway know which route
to use.
- Original Message -
From: "Tangled Up in Blue"
To:
Sent: Friday, December 14, 2001 5:49 AM
Subject: RE: Mask in L3 Packet [7:29182]
> sorry for the double post, and i meant to say that
Yes, the major network prefix includes all of its subnets. But once
you've subnetted a prefix, you can't assign that prefix to an interface
because you'll end up with overlapping network addresses.
For example, let's say you have the address 172.16.1.0/24 and want to
split it into two subnets.
er.
Subnet masks are a Local thing.
I hope this helps...
Alan~
- Original Message -
From: "Steven A. Ridder"
To:
Sent: Friday, December 14, 2001 2:07 PM
Subject: Re: Mask in L3 Packet [7:29182]
> Say I have 2 networks:
>
> Network 1. 172.16.x.x/16
> and
>
PROTECTED]
Subject: Re: Mask in L3 Packet [7:29182]
Say I have 2 networks:
Network 1. 172.16.x.x/16
and
Network 2. 172.16.2.x/24
We all agree that they are two different networks, right?
Now if Host A on
Network 1 is 172.16.2.1/16
and
Host B is on Network 2 is 172.16.2.1/24,
How does the host
IL PROTECTED]]
> Sent: Friday, December 14, 2001 2:07 PM
> To: [EMAIL PROTECTED]
> Subject: Re: Mask in L3 Packet [7:29182]
>
>
> Say I have 2 networks:
>
> Network 1. 172.16.x.x/16
> and
> Network 2. 172.16.2.x/24
>
> We all agree that they are two different netwo
You can't do that, it's a no no, network 1 thinks he's connected to
172.16.0.1 - 172.16.255.254 which obviouly OVERLAPS network 2, see:
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/ip.htm
Dave
"Steven A. Ridder" wrote:
>
> Say I have 2 networks:
>
> Network 1. 172.16.x.x/16
/16, it would work.
ejh
-Original Message-
From: Steven A. Ridder [mailto:[EMAIL PROTECTED]]
Sent: Friday, December 14, 2001 2:07 PM
To: [EMAIL PROTECTED]
Subject: Re: Mask in L3 Packet [7:29182]
Say I have 2 networks:
Network 1. 172.16.x.x/16
and
Network 2. 172.16.2.x/24
We all
Because the major network was subnetted, it includes all networks under it.
Therefore it's the same network, just subnetted. Do I have it right?
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=29232&t=29182
--
FAQ, list archives
** PRIVATE **
The problem here is that your premise is incorrect. 172.16.0.0/16
*includes* 172.16.2.0/24 so they are *not* different networks. If you
configure your VLSM correctly you will not have this problem.
Let's say you had a router with two ethernet interfaces. You would not
want to co
Say I have 2 networks:
Network 1. 172.16.x.x/16
and
Network 2. 172.16.2.x/24
We all agree that they are two different networks, right?
Now if Host A on
Network 1 is 172.16.2.1/16
and
Host B is on Network 2 is 172.16.2.1/24,
How does the host know that the second host is on a different netw
>From its own local config. The mask isn't in the IP packet, which does
come as a surpise to some people! If this isn't what you're getting at,
just let us know...
Priscilla
At 08:20 AM 12/14/01, you wrote:
>This may sound like a dumb quesion, but if I send a packet to a different
>host, w
sorry for the double post, and i meant to say that
"If it sees by the subnet mask that this address is not local, it strips the
MAC info and the netmask and forwards the packet to the default gateway."
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=29186&t=29182
---
The sending host uses its own address and mask to decide whether the
destination host is on the local subnet or not. If not then the packet is
forwarded to the default gateway (unless the host is running dynamic
routing). When the packet reaches the router, the router checks the
destination IP ag
good question. if i understand you, you are wondering how the remote device
knows your subnet mask? the answer is it does not and it doesn't care either.
when you send a packet from your PC to another host in the same network for
instance you are saying, "according to my network, defined by my ne
good question. if i understand you, you are wondering how the remote device
knows your subnet mask? the answer is it does not and it doesn't care either.
when you send a packet from your PC to another host in the same network for
instance you are saying, "according to my network, defined by my ne
21 matches
Mail list logo
