What IP for network printer ?

[Don Phillipson]

Anomalies persist in a new Brother DFC 540CN
printer attached as a network device to upstairs
PC (itself networked by wireless to downstairs PC
which provides both with (wireless) WWW access.)

A. Users of this NG told me I needed a cross-
over Ethernet cable (not straight through as
in Brother documentation.) This worked OK
for test print (text).
B1. Brother BRAdmin diagnostics now report
print function OK but scanner function unready.
B2. I can print text (OK) from Wordpad but not
colour graphics (from Photoshop.) Unexpectedly,
when graphic printing failed there was no report of
this failure, i.e. no / Printer / Properties buffer
reported printing error (and no buffer was saved for
future printing, as happened earlier when text test
print failed.)

IP addresses for all these devices might be set
wrong. I set two of these manually (months ago):

#1 Downstairs PC (with router, hub of the home
network) was set manually at IP = 192.168.1.101

#2 Upstairs Belkin Wireless G card was set manually
at IP = 192.168.1.102
These IPs seem to work OK i.e. successfully connect
upstairs and downstairs PC in my home network.

#3 is the upstairs Ethernet card, into which the
Brother printer is connected. This generated
APIPA = 169.254.136.169

#4 is the printer, which reports
APIPA = 169.254.11.192

MAIN QUESTION: should I manually reassign all these IPs
into the same family, the same as my home network,
and would this solve problems B and C above?
I thought of making them simply
#3 (upstairs LAN card) = 192.168.1.103
#4 (printer on LAN card) = 192.168.1.104
This notionally puts all four devices into a single network.
But do I need two networks (one linking the two home
PCs, the other linking printer to upstairs PC) ?

(Supplementary Q: I do not see why APIPA for the
two upstairs devices were in different "families" i.e.
APIPA = 169.254.136.169
and
APIPA = 169.254.11.192
Should they not be both the same?
Will it disable either to reset them into home
network IPs of family 192.168.1.xxx ? )

(Supplementary Q2: Belarc software reports IPs like
Auto IP Address: 192.168.1.102 / 24
What does the / 24 mean at the end of the line? Does
it mean there is logical room for 24 more devices
in IP family 192.168.1.xxx ? )

 

[Warren Block]

Anomalies persist in a new Brother DFC 540CN
printer attached as a network device to upstairs
PC (itself networked by wireless to downstairs PC
which provides both with (wireless) WWW access.)

A. Users of this NG told me I needed a cross-
over Ethernet cable (not straight through as
in Brother documentation.) This worked OK
for test print (text).

Now you can know the rest: crossovers are rarely useful, because they
limit a network to two devices.

B1. Brother BRAdmin diagnostics now report
print function OK but scanner function unready.

Cheap AIO + network scanning = good luck. Maybe it'll work, but don't
count on it.

B2. I can print text (OK) from Wordpad but not
colour graphics (from Photoshop.) Unexpectedly,
when graphic printing failed there was no report of
this failure, i.e. no / Printer / Properties buffer
reported printing error (and no buffer was saved for
future printing, as happened earlier when text test
print failed.)

Likely a software problem. If you can print text, it's not the network.

IP addresses for all these devices might be set
wrong.

I had a lot of text in response to what followed, but got so confused
that I deleted it all. It sounds like you are trying to combine
multiple networks in various complex ways, but it's hard to tell.

So I'm going to make a recommendation and then respond to one or two
other things directly.

Get a router with a DHCP server, or enable the one that's in yours
already, or maybe just start using it.

A network computer needs more than an IP address, it needs a netmask, a
gateway, and DNS servers. Without those, you'll have limited--possibly
zero--network functionality.

When you turn on a client computer (or network printer), it requests all
that information from the local DHCP server. So a one-time setup on the
DHCP server covers your whole network--you don't have to do a thing.

Except for network printers. DHCP addresses can move, and you want the
printer to always have the same address, so the computers always know
where it is. So you can manually assign an address to it, or you can
tell the DHCP server "always give the printer's MAC address this IP
address".

Go and look up the admin web page for your router. Check it for DHCP.

If it doesn't have DHCP, see this post for a very nice replacement for
free:

http://groups.google.com/group/comp.unix.bsd.freebsd.misc/msg/6ba51671906578ca?dmode=source

I set two of these manually (months ago):

#1 Downstairs PC (with router, hub of the home
network) was set manually at IP = 192.168.1.101

#2 Upstairs Belkin Wireless G card was set manually
at IP = 192.168.1.102
These IPs seem to work OK i.e. successfully connect
upstairs and downstairs PC in my home network.

Can't tell what you mean by "successfully connect", but okay.

#3 is the upstairs Ethernet card, into which the
Brother printer is connected.

Sounds like you used that crossover to create a little network of the
printer and the computer. Don't do that, you'll have to bridge the
two networks, and on Windows that could require hippos or ninjas or
hipponinjas.

Connect the printer to your real network at the router, at least for
testing.

This generated
APIPA = 169.254.136.169

#4 is the printer, which reports
APIPA = 169.254.11.192

That's network language for "Daddy, why won't the man give us a DHCP
server so we can have our own addresses? We asked for a real address,
and nobody gave us one, so we just picked randomly."

MAIN QUESTION: should I manually reassign all these IPs
into the same family, the same as my home network,

Yes, preferably via DHCP.

and would this solve problems B and C above?

B1, probably not but maybe. B2, well, the same. What's C?

(Supplementary Q2: Belarc software reports IPs like
Auto IP Address: 192.168.1.102 / 24
What does the / 24 mean at the end of the line? Does
it mean there is logical room for 24 more devices
in IP family 192.168.1.xxx ? )

It's CIDR notation. It means you have 256 addresses minus two reserved
and four used, giving up to 250 more devices.

 

[Don Phillipson]

Get a router with a DHCP server, or enable the one that's in yours
already, or maybe just start using it.

I am genuinely grateful for this analysis. I have always worked on
PCs (24 years now) on a strictly functional basis, i.e. try to learn
new info (e.g. DHCP processes) only when I know I need to -- as
now: e.g. installed Oct. 2006 a Trendnet 432BRP (wireless) router (with
DHCP) simply as a hardware firewall when I connected with wireless
broadband Internet. (No broadband cable serves my address, so high
speed Internet is available only wirelessly: and when we added a 2nd PC
upstairs in Nov. 2007 I added a wireless card to enable broadband
Internet through the router.)

Existing network is thus:

Upstairs PC with LAN cable to upstairs printer
Upstairs PC has wireless card
i.e. connects with
Downstairs Trendnet wireless router which connects
between the ISP's wireless modem (and out to the WWW)
to the Downstairs PC
with Marvell Gigabit LAN card

None of these components can be easily relocated. The
wireless modem does not work upstairs (perhaps because
of interference from a TV antenna tower) and the new printer
must remain upstairs for its user's convenience, i.e. may not be
cabled to the router downstairs. The plan therefore is:

1. Renumber all these devices (wired and wireless)
as xxx.100, xxx.102, xxx.104 and so on, all in the same network.
2. After rebooting, try for upstairs printer both LAN cables (straight
through and crossover) expecting them to behave differently.
3. Read Trendnet documentation for DHCP (avoided up to now
on functional lines. I did not know what DHCP stands for.)

Does the sequence (order) of IP numbering matter? I could
easily renumber xxx.100, xxx.110, xxx.120, leaving unused
space to renumber devices later, if they worked better in
a particular sequence. Or should numbering be consecutive,
with no unused spaces?

When you turn on a client computer (or network printer), it requests all
that information from the local DHCP server. So a one-time setup on the
DHCP server covers your whole network--you don't have to do a thing.

Except for network printers. DHCP addresses can move, and you want the
printer to always have the same address, so the computers always know
where it is. So you can manually assign an address to it, or you can
tell the DHCP server "always give the printer's MAC address this IP
address".

Sounds like you used that crossover to create a little network of the
printer and the computer. Don't do that, you'll have to bridge the
two networks, and on Windows that could require hippos or ninjas or
hipponinjas.

OK: it sounds as if manual renumbering (and the correct cable) will solve
this.

Connect the printer to your real network at the router, at least for
testing.

Possible for testing, but not daily use -- so I shall try at first
manual reassignment of IP addresses, then review via DHCP menus.

Yes, preferably via DHCP.

To Be Arranged, when I get into the DHCP menu. It sounds
as if (after reassigning IPs) DHCP ought to see all the devices
and perhaps control them. I can imagine how thiis requires
a standard LAN cable to the printer rather than a crossover.

Supplementaries:
1. I am uncertain how reliably the DHCP menu will see
the upstairs devices, because the in-house (wireless)
network has worked only 80 pct. of the time. But perhaps
improved configuration will make this more reliable.
2. The Trendnet manual tells me this router has
TCP/IP, NAT, PPPoE/PPTP, HTTP, DHCP Server/Client.
I know Windows required me to add a TCP/IP device in
the first place, but not for PPP. So I hope Windows
requires me to add nothing for full DHCP functionality.
3. If this Windows network is successfully configured,
I imagine it will behave just the same in Linux (Xandros
= Debian.)
4. Was NG comp.periphs.printers the right place to
ask these questions or should I have asked in a
Windows networking NG in the first place?
5. Happy New Year to you, and thank you again.
Strict functionalism means I never know what I need to
learn until a problem halts me: and you have pointed
me in the right direction, towards DHCP, whatever
those initials stand for . . .

 

[Warren Block]

Upstairs PC with LAN cable to upstairs printer
Upstairs PC has wireless card
i.e. connects with
Downstairs Trendnet wireless router which connects
between the ISP's wireless modem (and out to the WWW)
to the Downstairs PC
with Marvell Gigabit LAN card

None of these components can be easily relocated. The
wireless modem does not work upstairs (perhaps because
of interference from a TV antenna tower) and the new printer
must remain upstairs for its user's convenience, i.e. may not be
cabled to the router downstairs. The plan therefore is:

1. Renumber all these devices (wired and wireless)
as xxx.100, xxx.102, xxx.104 and so on, all in the same network.
2. After rebooting, try for upstairs printer both LAN cables (straight
through and crossover) expecting them to behave differently.

Crossover will allow the printer to speak to the computer, straight will
not do anything. Neither will be very useful for what you're trying to
do.

If the upstairs PC is the one that uses the printer, attach via USB and
you'll (probably) have full functionality on that PC. Only that
computer will be able to use the printer, of course. You can probably
share the printer via Windows, but that computer will have to be on for
the other computers to use the printer.

3. Read Trendnet documentation for DHCP (avoided up to now
on functional lines. I did not know what DHCP stands for.)

Plug it into the search engine of your choice, or use Wikipedia.

Does the sequence (order) of IP numbering matter? I could
easily renumber xxx.100, xxx.110, xxx.120, leaving unused
space to renumber devices later, if they worked better in
a particular sequence. Or should numbering be consecutive,
with no unused spaces?

As long as you don't use reserved addresses and don't use any address
more than once, no. DHCP will do that for you automatically.

OK: it sounds as if manual renumbering (and the correct cable) will solve
this.

No. You have two networks and need one.

To Be Arranged, when I get into the DHCP menu. It sounds
as if (after reassigning IPs) DHCP ought to see all the devices
and perhaps control them. I can imagine how thiis requires
a standard LAN cable to the printer rather than a crossover.
No.

1. I am uncertain how reliably the DHCP menu will see
the upstairs devices, because the in-house (wireless)
network has worked only 80 pct. of the time. But perhaps
improved configuration will make this more reliable.

Read up on DHCP. The clients ask it for information.

2. The Trendnet manual tells me this router has
TCP/IP, NAT, PPPoE/PPTP, HTTP, DHCP Server/Client.
I know Windows required me to add a TCP/IP device in
the first place, but not for PPP. So I hope Windows
requires me to add nothing for full DHCP functionality.

No, even Windows does DHCP. All you have to do is tell it "configure
automatically".

3. If this Windows network is successfully configured,
I imagine it will behave just the same in Linux (Xandros
= Debian.)
Yes.

4. Was NG comp.periphs.printers the right place to
ask these questions or should I have asked in a
Windows networking NG in the first place?

This is not Windows networking, it's TCP/IP networking. There are
probably other newsgroups which would be more appropriate.