Welcome to Omgili,
Omgili ( Oh My God I Love It ;) is a search engine for discussions. With Omgili you can find answers and solutions, debates, discussions, personal experiences, opinions and more... To learn more about Omgili click here.
This is a complete preview of the discussion as it was indexed by Omgili crawlers. Use this preview if the original discussion is unavailable.
Click here to view the original discussion.
[http://forums.dpreview.com/forums/readflat.asp?message=29061963&changemo...]
Click here to search for discussions with Omgili discussions search engine.
 |
Printers, IP addresses, and DHCP: PC Talk Forum: Digital Photography Review
I'm pulling out what little hair I have left.
My several Ethernet-connected printers are continually having their IP addresses changed.
Obviously DHCP is assigning new addresses.
I understand that.
What I don't understand is what triggers DHCP to do that.
This messes me up, because I'll set a browser shortcut to the IP address of the printer, mainly so I can view its internal Web server and view statistics, such as paper usage and ink levels.
Of course, every time the IP address changes, the browser shortcut is no longer any good.
And some software that I use is having trouble finding the printers when their IP addresses change.
Yes, I can assign a fixed IP address to each printer that's outside the range of addresses controlled by DHCP.
That probably makes the most sense, but I'm concerned that someone else coming into my home (like my not-so-techie son) might not understand how I have things configured (this is the "will they know what to do if I get hit by a truck [lorry]" rule).
There also are other devices connected to the switch, including a RAID array, two wireles access points, and some other goodies.
I don't know if the router supports MAC/IP address binding, but that would seem to be getting too complex for a small home network of about 15 nodes.
There is no server on the network.
The setup: Three XP PCs, two color laser printers, and my wonderful HP Z3100 printer all plugged into a 24-port switch which is connected to port #8 (the uplink port) of a Linksys BEFSR81 8-port wired router.
The switch and router are plugged into a UPS, so power is never lost unless I choose to power down.
Thanks for your input.
|
|
DotCom Quote: :
>
I'm pulling out what little hair I have left.
>
>
My several Ethernet-connected printers are continually having their
>
IP addresses changed.
Obviously DHCP is assigning new addresses.
I
> understand that.
What I don't understand is what triggers DHCP to do
>
That.
Lease duration is by default not infinite in the configuration of most DHCP servers.
Hence, when the clients reach a predetermined point in their total lease duration (50%), they contact the DHCP server again (an operation known as a DHCPREQUEST) and ask something to the effect of "hey, is it OK for me to continue to use this IP?" Depending on its situation, the server may NACK that request which causes a different IP to be allocated.
Obviously, extending the lease duration to a very long interval is one workaround, but there are probably better fixes for your problem...
>
This messes me up, because I'll set a browser shortcut to the IP
>
Address of the printer, mainly so I can view its internal Web server
>
And view statistics, such as paper usage and ink levels.
Of course,
> every time the IP address changes, the browser shortcut is no longer
>
Any good. And some software that I use is having trouble finding the
>
Printers when their IP addresses change.
>
>
Yes, I can assign a fixed IP address to each printer that's outside
>
The range of addresses controlled by DHCP.
That probably makes the
>
Most sense, but I'm concerned that someone else coming into my home
>
(like my not-so-techie son) might not understand how I have things
>
Configured (this is the "will they know what to do if I get hit by a
>
Truck [lorry]" rule).
There also are other devices connected to the
>
Switch, including a RAID array, two wireles access points, and some
>
Other goodies. I don't know if the router supports MAC/IP address
>
Binding, but that would seem to be getting too complex for a small
>
Home network of about 15 nodes.
There is no server on the network.
15 nodes is a considerable "home" network :)
>
The setup: Three XP PCs, two color laser printers, and my wonderful
>
HP Z3100 printer all plugged into a 24-port switch which is connected
>
To port #8 (the uplink port) of a Linksys BEFSR81 8-port wired
>
Router. The switch and router are plugged into a UPS, so power is
>
Never lost unless I choose to power down.
>
>
Thanks for your input.
I would suggest checking whether your DHCP server is capable of "reservations".
Most are. In a nutshell, the DHCP server is configured to recognise a specific device by its MAC (physical) address, and to always hand out the same "reserved" IP to that device.
For convenience, reservations can fall into the same IP scope used by the rest of the network so that no futher configuration is needed either on the devices (printers) or any clients used to access them.
All it takes is a one-off administrative configuration change to the DHCP server to add the reservations.
|
|
|
The most likly cause of the IP being change is the device going to sleep and not renewing the lease before it expires.
Morris
--
Image control: Zoom out | Zoom 100% | Zoom in | Expand / Contract | New window
|
|
Neither of those solutions should be onerous.
Document your network setup for your own and others' reference.
DotCom Quote: :
>
>
Yes, I can assign a fixed IP address to each printer that's outside
>
The range of addresses controlled by DHCP.
That probably makes the
>
Most sense, but I'm concerned that someone else coming into my home
>
(like my not-so-techie son) might not understand how I have things
>
Configured (this is the "will they know what to do if I get hit by a
>
Truck [lorry]" rule).
>...
>
I don't know if the router supports MAC/IP address
>
Binding, but that would seem to be getting too complex for a small
>
Home network of about 15 nodes.
There is no server on the network.
|
|
There is a solution intended just for this problem.
You need to give your printers "Static" or "Fixed" IP addresses.
Check the manual for each printer and assign them each a unique address, and they will never change.
The only caveat, you must give them addresses that the DHCP server will not attempt to assign to other devices that my join your network.
Go to your router and look for the DHCP section and create a DHCP starting point.
Typically that may be 192.168.1.100.
You'll really only want to change just the last group of digits (.100), though .100 is actually a good starting point.
Put your printers at, for example .50, .51, and .52.
It may also make sense to assign fixed IPs to any computer that never leaves your home network, i.e.
Any desktop PC that doesn't travel.
It also is good form to set up a system you can remember, Printers in one range, PCs in another range, Dynamic IP (DHCP) in a different range, networked media devices in their own range, etc.
|
|
After re-reading your original post, let me add to my comment.
Static IPs are the actual intended solution to your problem.
Based on your comments regarding the issue of others not knowing what you've done, create a text document that lays out all the assigned IP addresses of everything on your system.
Place that text file on each machine if you feel that helps.
DHCP was really only meant for those machines "visiting" your network, but winds up being used by those without the knowledge of how to set up proper networking.
|
|
Static ips are the easiest way to go for your printers.
I'm not sure why static ips would confuse anyone if you were gone for a while (if it does, they shouldn't work on your router).
As for how to keep track of them, that's what your hosts file is for (/etc/hosts), i don't remember where the hosts file is located on a windows machine, do a search for it and add the ip addresses and names there like:
192.168.1.250 printer1name
192.168.1.251 printer2name
etc.
|
|
|
Or, after setting the static IPs, put a label on each printer with its static IP.
Also assigning IPs by MAC in the router is just as acceptable of a solution (and probably easier), then you can just keep the list of IPs, MAC addresses and which printer they belong to attached to the router for everyone's reference, or just e-mail the list to everyone so they'll have it for future reference.
In your original question, you already seem to know the solutions, and they're both simple.
--
- Eric, http://www.InvisibleRobot.com/
Image control: Zoom out | Zoom 100% | Zoom in | Expand / Contract | New window
|
|
|
Some routers also allow the setting of "Static DHCP", meaning basicly that the DHCP server will give the same IP address to the same MAC-address, and no other device can get it.
Also: you might want to try using the UNC names of the printers, rather than IP addresses..
|
|
|
Quote: :
> Also: you might want to try using the UNC names of the printers, rather than IP addresses..
And what would you recommend he use as a name server to host the UNC names?
--
- Eric, http://www.InvisibleRobot.com/
Image control: Zoom out | Zoom 100% | Zoom in | Expand / Contract | New window
|
|
I'm not familiar with the Linksys BEFSR81 but if it can function as the network's DNS server it may translate names in it's DHCP client table to their associated IP addresses.
If not, you would have to edit the hosts file as you say.
Eric Quote: :
>
Quote: :
> >
Also: you might want to try using the UNC names of the printers, rather than IP addresses..
>
>
And what would you recommend he use as a name server to host the UNC
>
Names?
>
> --
>
- Eric, http://www.InvisibleRobot.com/
>
Image control: Zoom out | Zoom 100% | Zoom in | Expand / Contract | New window
|
|
Most printers do have netbios capability built in.
Works just fine in home networks.
|
|
DotCom Quote: :
>
Yes, I can assign a fixed IP address to each printer that's outside
>
The range of addresses controlled by DHCP.
That probably makes the
>
Most sense, but I'm concerned that someone else coming into my home
>
(like my not-so-techie son) might not understand how I have things
>
Configured
There isn't that much to such a setup...just write it on a small piece of paper and tape it to the machines.
I always see label-maker style labels on equipment denoting IP addresses, names, and other information.
That way a technician should be able to quickly tell whatÂ’s going on.
|
|
|
|