Solved a network problem "a" and caused "b"?

[Bigglez]

My delight over fixing last week's DSL modem delay
problem noted in this thread was not to last. I now
have a new problem.

Although the new router/firewall allows WAN (internet)
traffic to each of the PCs on the wired and wireless
parts of the network, it is no longer possible to send
files from one PC to another using Windows Explorer.

After an hour of tech support from Linksys who suggested
removing the firewalls, and a few other changes that I don't
understand at all, we got limited connectivity from some PCs
to others. I had to remove and replace the network config
on each PC, by running the wizard several times on each.

Then I started to think that perhaps the workgroup
switch (in our home, on a 100ft tenbaseT cable from the
lab, where the router and DSL modem live), was bad.
This is the second one in five years. Perhaps the exposed
and long cable is at fault somehow? First the home-end
switch, then the lab-end router, now a second switch
failure?

To test my theory I reset the old DSL router to a
different IP address (192.168.1.2) and swapped
out the existing workgroup switch. This 'lifeboat'
allows the old router to act as a limited four port
switch, as I don't have access another that I could
borrow for testing.

Bingo! That did it. I now have full access to all
PC nodes, and very fast ping response and tracert times.

I'm looking to buy a new combo router with wireless
access point, to replace the new workgroup switch.
This will free up the existing wireless access point
in the home, so it can be deployed in the lab to
expand our existing wireless coverage.

The last piece of the puzzle (I hope) is that I can no
longer talk to the NAS after replacing the dead switch.
I can 'see' its IP address., so I think it has an IP address
mismatch or conflict. Hopefully that's all.

I'm spending hours at a crack on network issues
over the last few days. I don't understand most of
this stuff, and I haven't found many people that do.
Hopefully my planed changes will work.

A network that is neither seen nor heard is a good one
in my book.

List of equipment in the network:
Pool house (lab):
Dedicated CO line with filters
VisionNet E200ER ADSL Modem (2005?)
Linksys BEFSX41 Broadband Firewall Router (new)

Main house (closet):
Linksys EZXS88W 8 Port Workgroup switch (new yesterday)
Linksys WAP54G V.2 Wireless G Access Point (2007?)
Netgear ReadyNAS Duo (2008)

Junk Pile:
Linksys EZXS88W 8 Port Workgroup switch (2008)
Linksys BEFSR41 V.2 EtherFast DSL Router (2001?)

[kheston]

Couple things off the cuff:

1) if all of your PCs can see the Internet but not each other, it is likely that your 10/100 switch is not having a problem (this assumes the computers were hooked to the switch and the switch was hooked to the new router)

2) if the new network included an address range change (eg 192.168.0.0/255.255.255.0 to 192.168.1.0/255.255.255.0), all of your PCs set up for DHCP could do with a reboot. Also, any static IP address settings should reflect the change

Try accessing shares between computers with UNC paths that use host names then try with IP addresses (\\myhomepc1\sharename then \\192.168.1.5\sharename) and see whether one works better than the other. Your computers are talking to one another (transferring files, etc.) via a windows technology called Netbios. I find Windows XP to be quite a bit more finicky about file/printer sharing than W2K or Win98 ever were. Googling on the subject may offer some insight.

hth

[Bigglez]

I may have an hour to work on this today. Thanks for the suggestions,
I have already done some limited testing based on your hints.

1) if all of your PCs can see the Internet but not each other, it is likely that your 10/100 switch is not having a problem (this assumes the computers were hooked to the switch and the switch was hooked to the new router)

That would be great! However, in testing with the new switch and
the old one (both of the same model), the old one causes the
timeouts when pinging by either DCHP assigned DNS or Share names.
I'll revisit this when I have the NAS problem solved.

2) if the new network included an address range change (eg 192.168.0.0/255.255.255.0 to 192.168.1.0/255.255.255.0), all of your PCs set up for DHCP could do with a reboot. Also, any static IP address settings should reflect the change.

Yes, I realized that too late, and ran the XP OS wizard to
set up a new network. Probably wasted time and may have
invited new problems as well.

Try accessing shares between computers with UNC paths that use host names then try with IP addresses (\\myhomepc1\sharename then \\192.168.1.5\sharename) and see whether one works better than the other. Your computers are talking to one another (transferring files, etc.) via a windows technology called Netbios.

Okay, that testing is complete and I do indeed have peer to
peer file swapping on any member of the group (except my
wife's NB is with her and not here to try for a few days).

I tried it both ways (share names and DNS address) and both
have lightning fast response times.

The next task is to recover the Netgear NAS, which appears
to be on line (pings okay) but can't be accessed or discovered
by the Net Gear Raidar utility. Next up is to take it off the
LAN and try to get access from a dedicated PC.

Also, the new router can only be accessed or configured
from the direct connected PC, and not any other PCs (on
the other side of the new workgroup switch).

I assume that a workgroup switch is a device that relays
traffic both ways? Basically a device to multiply branches
of the network and serve more client hardware?

A Router, OTOH, acts based on the content of the
traffic messages, right?

[kheston]

Biggelz,

You are essentially correct in how you're differentiating routers from switches. As technology advances, the lines become more and more blurry (eg. a layer-3 switch is capable of performing some packet routing that only routers used to do), but you've got the gist of it.

The simplest difference between routers and switches is this: switches hook computers together and routers hook networks together. With just a switch, your home PCs can only see each other (those on their own network). A router is required to see computers outside of your network. It's the router that says, "the address you're looking for isn't on the network I manage" and forwards it to another router (via a gateway). If that router doesn't manage the address you're looking for, it forwards the request to yet another router and so on.

Routers often come with "filters" that deal with packets based on their content. Routing alone deals with getting packets to their intended destination (address). Filtering is a slower process that looks at a packet's content to decide what to do with it next. Your DSL router is actually a router/filter and does both (certain filters are set up by default).

hth

[Bigglez]

You are essentially correct in how you're differentiating routers from switches.
...
Routers often come with "filters" that deal with packets based on their content.

So called 'firewall'. right?

My motivation to change the old router to a router/firewall was to
off-load the protection to the router, and speed up the PCs
(each of which was doing virus scanning on internet traffic).

As of today I've recovered the NAS (Hurray!), by re-flashing the
BIOS. The data is okay, but there was that moment of "oh, sh*t"
when I couldn't get it to talk to me over the network. I suspect the
NAS was damaged by the other network problems, quite possibly
of my own doing while trying to recover from the router failure.

As one door closes it seems another opens, and now I've diverted
to fixing the PC that I was using for network debugging. It is very
sick, and probably another result of me removing its firewall while
doing other experiments.

The OS (Win XP pro) is deadly slow, and in an effort to fix it
I have probably made it much worse. Currently it won't boot past
the Windows welcome screen. The 'start' button bar (explorer)
is there, but none of the desk top icons. Somehow 50% of the
CPU is being used by some process I haven't identified.

The restore function is diabled and so I can't 'step back' a week
and work from that point. The software used to inspect the
registry found over 300 'errors', and when cleaned to zero another
crop appeared.

In other news I got the factory correct Garmin USB cable, and
solved that problem (can now talk to the GPS without messages
that the external power has been lost and reboots every 30
seconds). Time permitting I'd like to do some poking
around on the three variations of mini-USB cables and try to find why
they are not as they appear. (My suspicion is that the fifth pin is
used as a code of some sort - possibly just a resistor embedded
in the various plug mouldings).

Thanks again for everyone's help!