Travel Technology - The "Random Printer IP" thread - my Linksys WAG54G and HP2840

Good morning experts,

I use a Linksys WAG54G ADSL2 + 4 Port switch + WAP as a small network hub. There are 2 computers connected (C1 and C2) - C2 via blue cable to the dock (its wireless doesn't support WPA) and C1 wirelessly. The HP LJ2840 (P1) is connected via blue cable and a JetDirect adapter, and is always on - so my hope was that it would have a (relatively) stable IP...but!

The Linksys assigns IP addresses with a starting IP of 192.168.1.54. The problem is that there doesn't seem to be a workaround to it changing P1's IP address dependent on the number of Cs connected, such that P1 is always the last IP address assigned. So if 1 computer is turned on, C1 is assigned 192.168.1.54, P1 becomes 192.168.1.56 +2 (always +2 for some reason!). If 2 computers are connected, C1 is 192.168.1.54, C2 is 192.168.1.55, and P1 is 192.168.1.57 (ie +2 over the last IP assigned to a notebook).

The printer configuration needs has 3 printer ports, ranging from 192.168.1.56 up to 192.168.1.58. You have to manually configure every 2 or 3 days by pinging to find which IP P1 has been assigned.

I tried setting up the printer with a fixed IP of 192.168.1.60, but the Linksys won't recognise it.

If the above description is clear as mud, please let me know. But if you have some thoughts or advice, that would be greatly appreciated! I haven't tried changing "Client Lease time" on the Linksys BTW...

I tried setting up the printer with a fixed IP of 192.168.1.60, but the Linksys won't recognize it.

If the above description is clear as mud, please let me know. But if you have some thoughts or advice, that would be greatly appreciated! I haven't tried changing "Client Lease time" on the Linksys BTW...
I think it was pretty clear except for the underlined section above.

If you use a manually assigned IP address, then the Linksys doesnt really care about the device anymore. Its either there or its not and unless the linksys needs to send NATed traffic (that is, traffic from the Internet to the printer) then it doesnt need to know about the device.

You could change the lease time to like 10 days or something. That would probably do it...but thats a clunky fix.

I'd strongly suggest a static IP. From what I recall those linksys routers don't support DHCP reservations... or any real extension of DHCP.

Of course, my REAL advice is to (by way of shamless plug :D ) read the blog in my sig and install IPcop which does have a real DHCP server...which would allow you to set the printer to DHCP/auto but make sure it gets the same IP every time by having a reservation in the system.

I tried setting up the printer with a fixed IP of 192.168.1.60, but the Linksys won't recognise it.


If you use a manually assigned IP address, then the Linksys doesnt really care about the device anymore. Its either there or its not and unless the linksys needs to send NATed traffic (that is, traffic from the Internet to the printer) then it doesnt need to know about the device.
What I meant is that if I manually assign P1 as 192.168.1.60, I can't ping P1 so therefore can't print.
You could change the lease time to like 10 days or something. That would probably do it...but thats a clunky fix.
Good suggestion - will go to maximum lease time. (Agreed with your sentiments)
Of course, my REAL advice is to (by way of shamless plug ) read the blog in my sig and install IPcop which does have a real DHCP server...which would allow you to set the printer to DHCP/auto but make sure it gets the same IP every time by having a reservation in the system.
Someday, someday (as the song goes) - but good to know.

Much appreciated!

What I meant is that if I manually assign P1 as 192.168.1.60, I can't ping P1 so therefore can't print.

Good suggestion - will go to maximum lease time. (Agreed with your sentiments)


Much appreciated!

Thats really odd, as long as the IP you give the printer is on the same subnet (192.168.1.x) as the rest of the computers then it should work.
Can you set the gateway (192.168.1.1) and the mask (255.255.255.0) on the printer?

Are you trying to ping the printer by name and its failing or does it fail to ping the IP too?

Thats really odd, as long as the IP you give the printer is on the same subnet (192.168.1.x) as the rest of the computers then it should work.
Can you set the gateway (192.168.1.1) and the mask (255.255.255.0) on the printer?

Are you trying to ping the printer by name and its failing or does it fail to ping the IP too?
I set P1 192.168.1.60 (manual IP), 192.168.1.1 (gateway) and 255.255.255.0 as subnet. Ping to 192.168.1.60 timed out.

Tried to set P1 192.168.1.70, and limit the range of the Linksys to 192.168.1.54 - 192.168.1.63 (10 addresses), but that failed as well. Rationale - put the printer outside the range assigned by the Linksys.

Ah well...

Also checked "Printer Pooling" in "Printers" for each of the 4 IP ports for P1 which should make life simpler...

Did you reboot the switch/hub the HP JetDirect is plugged into? Seems like I have had this problem before, not with the same devices mentioned but I think after I rebooted all the devices involved I was able to ping and connect to the newly changed devices.


I set P1 192.168.1.60 (manual IP), 192.168.1.1 (gateway) and 255.255.255.0 as subnet. Ping to 192.168.1.60 timed out.

Tried to set P1 192.168.1.70, and limit the range of the Linksys to 192.168.1.54 - 192.168.1.63 (10 addresses), but that failed as well. Rationale - put the printer outside the range assigned by the Linksys.

Ah well...

Some random things you could try...

Add the printers IP to the DMZ on the router. Change the to one in the .100-.150 range.

If you use a static IP then you'll want to make sure you assign an IP value outside of the pool the Linksys box is using for DHCP. Since your subnet mask seems to be set properly, I suspect that you're not setting the IP properly on the printer when you set it statically and that's the main reason you can't ping the printer when trying the static IP. Also, rebooting wireless network equipment by power cycling it cures 90% of the problems you'll encounter.

Thanks all - I think the problem is the printer. I've created the DMZ 192.168.1.110, the range of IPs from 192.168.1.54 - 192.168.1.90, set P1 as 192.168.1.110/255.255.255.0/192.168.1.1 (gateway), and still I can't ping P1 directly from the Linksys. Plugged P1 directly into C1 and no response to pings.

Now to call HP to find out why...

Thanks all - I think the problem is the printer. I've created the DMZ 192.168.1.110, the range of IPs from 192.168.1.54 - 192.168.1.90, set P1 as 192.168.1.110/255.255.255.0/192.168.1.1 (gateway), and still I can't ping P1 directly from the Linksys. Plugged P1 directly into C1 and no response to pings.

Now to call HP to find out why...

2 ideas
1) Try taking a computer that is on the same network, disable DHCP on the computer, and set the IP for the one you tried for the printer. if you get internet, then the problem is the printer.

2) I'm thinking xyzzy might be on to something. Open up the access page for the router and see what the DHCP starting address is. When I was setting up by NAS I had to increase it to provide an IP that was not managed through DHCP

As long as nothing else on the network has the same address at the same second, then being inside the DHCP pool would not prevent you from pinging the IP.
When you ping by IP the router is not in the loop at all. You are throwing out bits to the entire subnet and saying "hey if you are you there then answer me!". Likewise all putting it in the DMZ does is mean that some kid on the same cable modem circuit can print to your pinter from outside your building...

If you've assigned the static (granted, outside the DHCP pool is better for testing) and the proper subnet mask and still cannot ping the device, something is wrong either on your computer or the printer....software or hardware.

Along the same lines, there is no need to ping the printer from the linksys, unless you need people from the outside world to be able to print. But that should be as valid of a test as pinging from a computer...one thing to check, the subnet mask on the linksys itself in the LAN setting. IF that is masked to something smaller than /24 (255.255.255.0) then that could keep you from pinging from the linksys to the printer).

It should have nothing to do with the DMZ. The starting dhcp address you mentioned is not the standard one for your router, as defined in the user guide for that product, so unless you have set up this stuff yourself to non-default values for other reasons, you might want to start all over with a hard reset of the routers configuration. The default dhcp configuration according to the manual should be 50 IP addresses starting at 192.168.1.100

I note that there are 2 linksys routers with the same model number. v1 has a manual, v2 doesn't. So, I'm basing this on the v1 manual. Is yours v1 or v2?

Just set up the printer with static IP addresses outside the range of any dhcp-managed IP addresses on your subnet, but with the same netmask within the same subnet. Then reset all routers and bridges on your network, but even that shouldn't be necessary, but you can try it.

You said something about the printer using three IP addresses? Does it have three network ports? How does that work? I suppose you could have 3 IP addresses on the same network port, but that seems unusual to me.

Even if you accidentally use an IP address in the dhcp-managed range, as long as that address isn't already in use by another device, it should still work, although that's not something you want to do under normal circumstances because it could cause problems later if/when you add more things to your network.

I agree with Spacebass, but the router also has a built-in switch, and switches have their own routing tables constructed on the fly. You shouldn't have to do a reset when you modify the IP address of something connected to the switch (or remove something, or add or swap something), but it might take a minute for the switch to recognize the change.

The other thing to do is to check for a firmware upgrade for your router. Have you done that? Never mind. I don't see any for either v1 or v2 on the linksys web site.

-David

Thanks guys - it's a v2, and no docs in the box apart from a fold out "how to configure" which is of no use. A bit busy at the moment, so will try all the suggestions and report back.

With the "printers", I've simply added additional ports (3 so far) when the Linksys assigns the equivalent IP.

If you use a static IP then you'll want to make sure you assign an IP value outside of the pool the Linksys box is using for DHCP....

This is exactly the way that I set up network printers and I never have had a problem with them.

I've never had a printer that needed an IP but what you are doing sounds right although it would be safer to move the printer's IP outside the DHCP zone.

If you use DHCP you should *EXPECT* variable IP's. If a variable IP isn't acceptable (and it apparently isn't in your case) then you can't use DHCP to assign the device's IP.

While I don't have exactly your hardware I do have a mix of DHCP and static IP's here and a far bigger group at the office that is also a mix of DHCP and static. The only time I had any headaches is when someone turned on DHCP on a server and we got strange behavior from having two DHCP servers on the net. Even then static IP's worked fine.

The default dhcp configuration according to the manual should be 50 IP addresses starting at 192.168.1.100
Just did a hard reset, and the starting IP was 192.168.1.64 with 191 IPs to assign...my reference to 54 earlier was a deliberate typo. Worried about those black helicopters... :)

I'm yet to get to the printer again.

The manual should be on the CD. Do you have the CD that came with it? There's no online manual for the v2 on the linksys site, under support/downloads.

I have no idea why you can't see it. Time to call linksys for support.

-David

I have no idea why you can't see it. Time to call linksys for support.

-David
Yes
:)

I don't know who was the first to mention it on this topic about WAG not having DHCP reserved addresses, but that was wrong.

just go to this "undocumented" page and you can enable it:
http://192.168.1.1/dhcp_reserved.asp

You can easily manage reserved DHCP addresses and assign them either by MAC or by hostname.

Just tried this (thank you for the tip BTW!).

Couldn't enter the IP 192.168.1.70 - had to add the Mac address as well. Did that, accepted (Settings saved).

Tried to ping 192.168.1.70, with no result...

Woohoo!

1. Set the printer (192.168.1.100) outside the range assigned by DHCP (192.168.1.64 - 192.168.1.80)
2. Set the DMZ zone as 192.168.1.100

Can now print to 192.168.1.100.

FT TT - the only place to be. Thanks all for your suggestions, especially Expat81. Welcome to FT, too!

It didn't work without setting the DMZ zone to the printers IP address? Very odd. The DMZ is supposed to be set (if you want it) to direct outside traffic to one computer. It makes that one computer (in your case, the printer) accessible from the WAN side .. in other words, the internet. You would normally use something like that to set up a web server on one of your computers.

Anyway, didn't we already suggest setting the printers IP address outside the range managed by the dhcp server?

Did you ever call linksys?

-David

It didn't work without setting the DMZ zone to the printers IP address? Very odd. The DMZ is supposed to be set (if you want it) to direct outside traffic to one computer. It makes that one computer (in your case, the printer) accessible from the WAN side .. in other words, the internet. You would normally use something like that to set up a web server on one of your computers.

Anyway, didn't we already suggest setting the printers IP address outside the range managed by the dhcp server?

Did you ever call linksys?

-David
1. It didn't work first time - so did the DMZ thing and turned the WAG54G off/on. I agree with you, the DMZ is almost certainly not needed, I was merely reporting what I did. :)
2. Already tried having the printer outside the DHCP range http://www.flyertalk.com/forum/showpost.php?p=6121010&postcount=10
3. Called linksys (1800) and it was engaged for 2 days - good service here in Oz eh?

Thanks again