network computers won't share files or printer anymore

[meksikatsi]

Hello all,

Network setup:

1 commercial rr connection on a home network - I'm experimenting.

This network was up and running for over 1 year - all computers had full communication with each other.

I changed out two computers for new dual core Intel machines with HPs XP media center edition, which my research indicates is XP Pro.

That's when computers started to be not available. I've seen others with this same complaint, so I want to start a thread which can explore why this is happening and how we can fix the issue - the whole permissions topic is very difficult to track down.

I've got a BEFSR81 Linksys router connected to the cable router (not a cable modem - static IP) and 7 computers and 6 cameras connected to a Linksys WRT54G with a workgroup switch hanging off it. The wireless router is connected to the wired router and I have only my work computer (which runs a VPN) hooked to that. All wired and wireless computers and cameras are connected to the 54G or the workgroup switch.

It WAS working very well. All equipment can still access the internet. The main issue is the shared printer which nobody can use but the computer it's directly connected to. I've gotten over the shared files thing by just using email to send files machine to machine - stupid but effective. @#$%^&

I've gone through everything many times - my opinion is that a security program changed something but I can't fathom why it would do it to every machine on the net - the cameras were not affected but they aren't on the dhcp server. But I cannot find what has changed - everything appears correct.

I started taking the net apart but haven't had a lot of time to work with it since there are so many components to check out. The one thing that worked was when I took sharing, etc. off of every computer and then started it up again.

Now, I can actually print from ONE of the machines to the printer on the printer computer. But still, no other computer can do this. There's some strange stuff going on. Why this one machine can connect is a mystery - all I did was turn sharing off and then on. btw, the computer I'm on is one of the new HPs and the one with the printer is a 2Kpro job.

For example, I just pinged these two machines from the other one and both are conversant. The printer machine is 192.168.1.100. It can ping 192.168.1.101 not a problem and can see it's files. 101 can ping 100 with no problem but when I try to run 192.168.1.100 I get that nasty message:

\\192.168.1.100 is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access. Access is denied.

Unfortunately, I'm the administrator. Why it runs one way and not the other has to be part of the mystery.

As I said, a lot of people are having this problem and I agree it's probably a security issue - but I've tried to turn any firewalls off. There might be some residual software still running but I've turned it off.

I'll take any and all suggestions, guys!!

And I believe it's something very simple. But I cannot find it.

Thanks to all,
Meksikatsi

[Kashif]

New install computers does have some security firewalls other then windows own? 2nd if not then did u checked windows firewall , for just check turn it off and try if it works then change the firewall settings.

3rd: Mac security is enabled and u entered mac addresses when u first start the whole network then enter the new mac addresses and apply.

[Fest3er]

...
I'll take any and all suggestions, guys!!

And I believe it's something very simple. But I cannot find it.

Thanks to all,
Meksikatsi

• delete McAfee and Norton from the computer, if they exist. Simply turning them off will leave the network stack screwed up; at a minimum, they must be disabled but still running. And they are so hideous, they will bring a 2GHz dual-core CPU down to 1 MHz speed. Deleting them is best.
• disable any and all other firewalls.
• triple-check file and printer sharing to be sure you have it properly enabled; there can be several places to check.
• disable UPnP on the router/gateways; you don't *really* want to allow Windows to make changes to your firewall, do you? :)
• painstakingly go through each pair of computers and verify whether or not they can talk to each other.
• ensure netmasks are correct.
• ensure you have only one DHCP server running.
• check the routing tables on each router for sanity[ensure each device on the network has a unique IP addr.

This should be a decent-enough start....

N

[meksikatsi]

Took me a while to get back on this thread - travel

Great suggestions N - I've got them all covered I believe EXCEPT the multiple dhcp servers.

The wired router is set up for dhcp and the wireless router plugged into it also set for dhcp.

I originally put the wired router in because I need to set static IP for a port to my cameras. So, I'm going to try setting static up until I get to the wireless router where dhcp will function.

One note, I did all this because it appears impossible to run static IPs and dhcp simlutaneously on the same router. I had cameras running static but it could not deal with computers while dhcp was up. I would run all static except my kids have wireless notebooks.

Anyway, thanks for the suggestions - in the wee hours of the night, I'll be grateful for having you look over my shoulder - I'll get back!

meksikatsi

[zeroth]

Don't count on being able to run simultaneous static and dhcp on any setup with a Linksys router involved.

~z

[meksikatsi]

Well, guys, I'm suitably :icon_redface:

But at least I found the problem and solved it. I did not think I had any security running on the computers - those new boxes that I added, I refused the Norton's. But when I tried everything that has been suggested, I still did not have success.

So I started over on the list. I got me a good Norton's removal tool and started surgery. Sure enough...Norton's was the culprit. It was still hiding there, pouncing and not notifying me.

Such an easy fix. Such a nightmare to find it.

Many thanks. What a relief. I knew it was something simple!
You guys are great!

meksikatsi

[Fest3er]

... One note, I did all this because it appears impossible to run static IPs and dhcp simlutaneously on the same router. I had cameras running static but it could not deal with computers while dhcp was up. I would run all static except my kids have wireless notebooks. ...

By the way, it *is* possible to run DHCP and static addressing on the same router. Technically, all addresses DHCP serves, including static addresses, must be allocated to its pool, and all other addresses assigned by other methods must come from outside the pool. In the past, some DHCP servers may have been programmed incorrectly in this respect.

To illustrate, suppose you have a Linksys router (IP 192.168.1.1, netmask 255.255.255.0) that supports static assignments, and suppose you have configured it to assign addresses in the range of .101 through .150. You can manually configure nodes with addresses in the ranges .2-.100 and .151-.254. (.0 is the network address, .1 is the router and .255 is the broadcast address.) You can tell DHCP to assign .101 to your desktop, .102 to your printer, .103 to your kid's computer, etc. This is done by 'relating' a node's MAC address to the respective IP address. Now, when DHCP gets a request, it checks the node's MAC addr; if it finds a match, it assigns the 'related' static address. If it does not find a match, it assigns a dynamic address. Regardless, all addresses it assigns must come from within its pool.

I know DHCP works this way on the Linksys WRT54GC (Linksys firmware) and on the WRT54G with DD-WRT firmware.

N

[LabASSistant]

Well, guys, I'm suitably :icon_redface:

But at least I found the problem and solved it. I did not think I had any security running on the computers - those new boxes that I added, I refused the Norton's. But when I tried everything that has been suggested, I still did not have success.

So I started over on the list. I got me a good Norton's removal tool and started surgery. Sure enough...Norton's was the culprit. It was still hiding there, pouncing and not notifying me.

Such an easy fix. Such a nightmare to find it.

Many thanks. What a relief. I knew it was something simple!
You guys are great!

meksikatsi

helped me too...

[meksikatsi]

that's great!