Hookup to Cable Modem

I tried to hook up an old linksys BEFW11S4 router to a cable modem and had
extreme difficulty. I ended up getting the wired network to work by hooking
the modem to the LAN instead of the internet port. However, it would not
connect the wireless to the internet. That same router worked flawlessly on
another system for both wired and wireless connections by hooking up to the
internet port. I thought of getting a router/modem combo, but the phone
system runs through the modem also. My next plan is to try a Linksys
WRT54X2. There are many more settings on this router. Any ideas on how to
get both wired and wireless connections working on a cable modem?

 

Like what, specifically?

All you accomplished was to completely bypass the router, essentially
turning it into a switch.

Can wireless systems connect to the router and communicate with wired
systems connected to that same router? In other words, check the local
networking first, before thinking about Internet access. You may have
to temporarily disable wireless security to verify full wireless
functionality, but I wouldn't run without better-than-WEP (and
preferably WPA2 AES) for very long.

Do a full factory reset on the router. It sounds like someone screwed
up the settings, err, I mean, customized the settings beyond
functional limits. The default settings should work in most cases.

As stated above, verify local networking first, then log into the
router and make sure it has acquired an IP address and related config
info from the ISP.

 

I could not communicate past the router until I moved the router to modem
cable from the Internet port to the LAN port. This got the wired connection
working, but not the wireless. The wireless could see the local network
except for the modem (it could see the router and the wired connection to
the desktop.

The WEB router only has WEP.

I started there and could not get past the router to the modem no matter
what I did.

That is what I did with the local network. I could not get past the router
to the cable modem and the internet until I moved the router to modem line
from the Internet port to the LAN port. Wired connection went past the
router to the modem and internet, but wireless would not, no security on
the wireless.

 

Yes, but connecting both the computer and the modem to a couple of the
router's LAN ports was effectively the same as connecting the computer
directly to the modem, so I wouldn't say that got it working.

Did you remember to reboot the modem after making the initial cabling
change? Usually, the modem's config only allows it to talk to the
first device it sees after a reboot/power-up, so if that was your
wired PC it won't talk to your router until you reboot the modem with
the router correctly connected, which is to say that the router's WAN
port needs to be connected to the modem.

During the time that you had the modem connected to a LAN port on the
router, it makes sense that the wireless computer couldn't see the
Internet. As stated above, since your modem can only talk to a single
device and you let that device be your wired PC, the wireless computer
had nowhere to go.

Bummer. If you live near other people, be prepared to share your
bandwidth and any open file shares. WEP security can be bypassed in
under a minute now.

I'm guessing you forgot to reboot the modem. Correct the cabling, then
reboot the modem, the router, and possibly the PC's, in that order. As
the modem restarts, it will find the router. In turn, the router will
request an IP address from your ISP. You can log into the router to
see if that is successful. Lastly, your wired and wireless PC's will
request an IP address from your router if you're using DHCP, and away
you go.

 

Yes, I rebooted.

Already changed that one out for a different application

That is what I did. Hopefully the other router will behave properly. Will
get access to it again Monday morning.

 

Monday was a messed up day and ended up going there Thursday. I started
with a factory reset on the router and restart on the modem (Arris TM502G
cable modem). I could not pass through the router to the modem. I copied
the computer settings (pre-router install) to the internet setting on the
Linksys WRT54GX2 router for a manual setup and still not communicating. I
tried all kinds of settings, but nothing would work. I experimented with
NAT, DNS, DHCP, etc., on the router and the computer, but could not get it
to pass through to the modem or internet. That same router works great in 2
other applications not involving a cable modem, but rather DSL. I am
totally unable to access any functions on the modem. There do not seem to
be any settings on it.

 

When I see things like "tried all kinds of settings" and "experimented
with", the first thing I think of is that it's time for another
factory reset. Be sure you aren't doing a simple device reset. Pushing
the reset button for up to about 10 seconds simply reboots the router
and doesn't reset the settings. With the router turned on, you should
press and hold the reset button for a full 30 seconds. You'll know it
did a full reset when you notice that the default user/pass is now
required to login, rather than the user/pass that you had set before.

Here's how I would proceed, if it were me:
1. Full 30-second factory reset of the modem.
2. Connect an Ethernet cable from the modem to the router's WAN port.
3. Reboot the modem so it learns the MAC address of the router.
4. Connect a computer (via Ethernet) to one of the router's LAN ports.
5. Log into the router and check the Status pages. Verify that the
router has requested and received a routable IP address from your ISP,
as well as one or more valid DNS addresses. Go to the router's Admin
page and use Ping or Traceroute to check connectivity FROM THE ROUTER
to an Internet IP address. (4.2.2.4 and 8.8.8.8 are two addresses that
are easy to remember.) If the router can reach those addresses, then
the path from the router to the Internet is good. At that point, if
you still can't pass traffic from your PC to the Internet, it's the
router itself that's blocking the traffic. Since you would have done a
full 30-second factory reset prior to this, things like access filters
will be disabled, so I would suspect a bad router.

Be ready to try a second Ethernet cable for any segment of the network
path that isn't working. Cables can and do go bad from flexing and
other handling.

Like virtually all cable modems, its configuration duties belong to
the ISP, so all you can do as a customer is view a few things like
signal levels, log files, MAC addresses, etc. It looks like the
modem's IP address is http://192.168.100.1.

 

I did SEVERAL of these full resets. Each time the settings went back to
factory.

Nope, no access through ping or trace. Tried that. Both routers are working
in other environments with no adjustments from factory other than custom
names and password protection on the wireless.

Same cable as used successfully in other environments.

Yes, correct.

 

What about the most important part of those steps, verifying that the
router successfully acquired a routable IP from your ISP?

By the way, does your ISP require you to register your computer's MAC
address with them? If so, you'll need to clone that MAC in the router
or you won't get Internet access.

And? Were you able to access the status pages in the modem? If so,
you're getting through the router.

 

No, it is not. That is the problem!

That is one setting I did not try.

No, I could not access the modem through the router.

 

I agree, that is the problem. Up to this point, I have assumed that
your ISP uses DHCP to assign you a routable IP address, but it's
possible that they use something else, such as PPPOE. Find out, either
by searching their web site or by calling them, whatever, because
until you can get them to assign you a routable IP, you're not going
anywhere.