Absolutely right, thank you for the clarification.
It's bad enough to be confused about TCP/IP without introducing even more issues.
>>> John Clogg <[log in to unmask]> 03/28 11:31 AM >>>
Close, but not quite right. 255.255.255.0 is a class C mask; 255.255.0.0 is
class B. The mask you mentioned (255.255.255.240) represents a subset of a
class C subnet.
-----Original Message-----
From: Doug Becker [mailto:[log in to unmask]]
Sent: Wednesday, March 28, 2001 10:26 AM
To: [log in to unmask]
Subject: Re: Networked Printers and New Sub Masks
TCP Primer:
TCP/IP specifies an address of ttt.xxx.yyy.zzz such as 192.168.0.1.
This is the address which can be used to find a device on the network.
Each portion of the address represents one byte: the 192 would be
represented as X'C0', the 168 as X'A8', the 0 as X'00', and the 1 as X'01'.
The entire packet of 192.168.0.1 would be represented as X'C0A80001'.
Ususally, this is a unique address and organizations register the over all
address.
This introduces the concept of the "over all" address [not a technical term]
using what is known as a subnet mask.
The subnet mask is a series of bits which identify an over all address by
which bits are turned on.
Suppose we have what is known as a "Class B" address.
The subnet mask for this would allow for 255 devices on the same "subnet"
and would be in the form of 255.255.255.0.
The hexadecimal equivalent of this is X'FFFFFF00'.
What happens is that the subnet mask is "ANDed" against the TCP/IP address;
in this case the X'FFFFFF00' is "ANDed" against X'C0A80001', leaving the
result X'C0A80000'.
This allows you to have 255 devices starting with 192.168.0.1, 192.168.0.2,
192.168.0.3... up to 192.168.0.255.
So your computer might be on 192.168.0.3, your first printer might be
192.168.0.12, your second printer might be 192.168.0.14, and so forth, up to
the maximum devices you can have on that subnet.
I should point out that 192.168.0.xxx is a reserved subnet which is to be
used internally on a local network or Intranet, and is ignored for purposes
of the Internet; it is for your internal use; so, trust me, there are a lot
of devices with this subnet in private homes and businesses.
There is another class, "Class C" where only 15 devices are able to be used,
and that is represented by 255.255.255.240 or X'FFFFFFF0'.
You might be on a "Class C" subnet.
"Class A" subnets are pretty much wide open and specific for use within an
organization (not in any way allowed public access outside of its domain).
Now, network printer addresses are configured within NPCONFIG.PUB.SYS with
the ldev (network_address = tt.xxx.yyy.zzz), where the ldev must be
configured in sysgen in the io section as:
:SYSGEN
sysgen> io
io> adev ldev=??? id=hptcpjd path=none class=(lp,class1,class2)
io> hold
io> exit
sysgen> keep
sysgen> exit
.
.
.
In NMMGR, if your printers are not on the same subnet, you must go into
NETXPORT.NI.LAN.INTERNET
This is an ugly navigation task which goes like this in NMMGR:
F1 - Open Config
F2 - NS
F2 - Unguided Config
F1 - Go to Netxport
F3 - Go to NI
From there, you have to either F6 - Modify a Network Interface Name or F5 -
Add.
On the next screen, pick F3 - Go to INTERNET.
Now you are at configured gateways.
Either F5 - Add a new gateway name or F6 - Modify.
The name doesn't matter so much, but try to make it meaningful.
Here you are at the Configured Reachable Networks [I told you navigation was
ugly].
At the top you must provide your "Neighbor Gateway IP Address".
This is the address of the router on your local subnet where you connect to
all those other routers on everybody else's subnet.
You have groups of three fields under this:
IP Network Address IP Mask (Optional) Hops
And each row is where you fill in the address of the Routers you want to get
to, for example:
192.168.3.51 255.255.255.0 3
Now the Hops is interesting.... This is how many bridges and routers you
expect to cross to get where you are going.
A small number of hops can be indicated for things on your Intranet
(assuming you have several subnets).
A much larger number of hops is indicated for things "out there" beyond your
firewall.
If you aren't sure, you can always do a TRACERT and reduce the number for
efficiency sake to establish a baseline.
I can guarantee you that if you do not identify the TCP/IP address, the HP
e3000 won't know how to get where it's supposed to go.
Be sure to to a save and VALIDATE before you leave NMMGR [ugly things
happen, otherwise].
When you move the printers around, and they come off your subnet, you will
have to go through this interesting exercise.
More than likely, you will have to change the addresses in the
NPCONFIG.PUB.SYS file as well.
The printers can be under any mask, on any subnet in the world, as long as
you specify the way to get there from the HP e3000.
[We do this over the Internet to a City nearby.]
Isn't that wonderful?
----------------------------------------------------------------------------
----------------------------------------------------------------------------
---------------------------------
>>> Joseph Rosenblatt <[log in to unmask]> 03/28 9:29 AM >>>
We have about fifteen printers configured to run on the network. We are
running out of IP addresses so the proposal has been made to add new
sub-masks. The printers would be put on there own sub-mask. They currently
reside on the only (help me here, gateway?, mask?, path?) along with the
CPU. If we move the printers to a new sub-mask what do I need to do? Do I
have to configure the sub-mask in NMMGR? Is it as simple as just changing
the addresses in NPCONFIG? Can the printers be on a different mask than the
CPU? Can the CPU be on a sub-mask?
As you can tell I don't have a great grip on the network side of things. Any
information, war stories or any other help would be appreciated.
Thanks,
Joseph
|
