- Bizarre problem - two hosts behind the same cable modem; one loses connectivity the other does not
- Posted by 2pac on July 10th, 2003
Issues:
I have got two PCs behind the same cable modem.
One of them frequently loses connectivity - the other does not. This
has continued for several months. I have taken traces - switched
cables / network cards without any result
Any help appreciated. This is the sequence of events
on network cable disconnect - PC 1loses IP address (this is expected)
on reconnecting the cable - the IP address is initially 0.0.0.0
(expected)
after some time - the PC automatically sends a DHCP broadcast
reqquesting for IP address
However, the DHCP server does not respond.
If these steps are repeated with the PC 2 - it always consistently
receives a DHCP response.
PC 1 however does receive a DHCP response if the cable modem is
rebooted and
ipconfig /renew is done
In addition, PC 1 sometime fails to connect to the DNS server even
when it has a valid IP address
Both the PCs run Win2k (same version) and are connected to a cable
modem via a hub. The hub ports work ok. I have switched ports without
any change in result
Also, if I statically configure the IP address and the DNS server in
PC 2, it does not help.Am wondering why.
Thanks for any responses
- Posted by $Bill on July 10th, 2003
2pac wrote:
I would replace the hub with a cheap router (< $50 these days for a Netgear
or Linksys) and have the router be your DHCP server - that should solve
your problem and give you better security in the process.
- Posted by Boyd Williston on July 10th, 2003
cal_2pac@yahoo.com (2pac) wrote in
news:d04df644.0307091922.25928ffe@posting.google.c om:
Nothing bizarre at all. Your two computers are fighting for the same IP
address from the ISP. One will always loose, and the fix is very simple:
don't use a hub, use a router.
- Posted by James Knott on July 10th, 2003
2pac wrote:
Are you paying for 2 IPs?
Do not set up a static address on a dhcp only system.
--
Fundamentalism is fundamentally wrong.
To reply to this message, replace everything to the left of "@" with
james.knott.
- Posted by 2pac on July 10th, 2003
Hi
Thanks for the responses. I am not sure if this will solve the
problem.
a) I pay for 3 internet DHCP IP addresses(this is comcast)
b) How does the hub interefere? From what I understand, it will be
faithfully forwarding the DHCP request from PC 1 and PC 2 as is
without any alterations (with the ethernet address of whichever PC
sent the request)
c) If (b) is correct - then how will a router resolve this problem.
d) I also face this problem even when one PC is turned off. The other
PC (which does not work) is still not able to get the DHCP response
Thanks again for your the suggestions
"$Bill" <news@SPAMOLAtodbe.com> wrote in message news:<3F0CDFEB.40903@SPAMOLAtodbe.com>...
- Posted by Scott Johnson on July 10th, 2003
"2pac" <__cal_2pac@yahoo.com> wrote...
You are flushing money down the toilet. This is essentially pure profit for
Comcast. I'll second (or third, or fourth) the suggestion that you get a
cheap router and then pay for only one IP address. The router will protect
you from most attacks, especially as you are running Windows. A router is
its own DHCP server for your PCs, and needs only a single IP address from
Comcast's network. Behind a router, it's none of Comcast's business how
many actual computers you have hooked up or how they are configured.
-slj-
- Posted by GlowingBlueMist on July 11th, 2003
I don't see the brand of cable modem you are using but if it is a Motorola
product you should be able to go to the "Address page" and look for
something with a header like "Known CPE MAC Address (Max ?)". I think CPE
stands for Customer Provided Equipment (read as computers usually).
The above question mark will be replaced by the total number of IP values
your ISP has the modem programmed to give you. At my place it used to be
set at 1 but lately it was bumped up to 7, not that I asked it to be raised.
Many people pay for multiple IP values and have ISP's that forget to raise
the CPE to that value causing exactly the kind of problems you are seeing.
"2pac" <cal_2pac@yahoo.com> wrote in message
news:d04df644.0307100938.40770a13@posting.google.c om...
- Posted by Me on December 24th, 2003
On 9 Jul 2003 20:22:39 -0700, cal_2pac@yahoo.com (2pac) wrote:
As has been stated, lose the hub, Bub. I work as a service tech for
the cable company and I see this ALL the time when people try to buy
extra IP's instead of using a router. As someone else has stated,
getting this problem fixed can be a nightmare. They'll send a tech to
your house that will contact a dispatcher. The dispatcher will say
"Yep! He's got X number of IP's." You'll go look to see how many
computers are getting IP's and it will say 1 on the diagnostic screen.
The dispatcher will claim it's your end. The tech will claim it's on
their end. Just spend the $30 on a router and be done with it.
