Re: Cannot Ping Beyond Default Gateway & DHCP Server
- From: dbir <dbir@xxxxxxxxxxxxxxxxxxxxxxxxx>
- Date: Wed, 26 Aug 2009 19:59:01 -0700
Thanks for your input.
Yes, I knew about MAC. Buy a new computer? Gotta tell TW. Buy a router?
Gotta clone the computer NIC's MAC into it.
Lets just say I found a way to temporarily alter the MAC for testing
purposes. For either computer at the other's house, with MAC unaltered, we'd
get absolutely nothing -- no IP address nor anything. Dumb as a brick. Just
as it should be.
Disguising a computer (by duplicating the authorized computer's MAC) was
enough to produce valid test results:
My computer or his disguised computer, on my line work perfectly. Both
computers access the world.
My disguised computer or his computer, on his line: (1) receives an IP
address, (2) can ping default gateway and DHCP server, (3) cannot ping DNS
servers (we get 2), nor any other IP address (i.e. google's). Of course,
that results in no access to any internet sites at all. Identical symptoms
on both machines.
(I get those server addresses from network adapter's Status>Support>Details.)
Also, when we swapped cable modems at TW yesterday, they scaned bar-codes,
so by the time we got it home & hooked up, TW servers already knew the new
modem's MAC. Access problem/symptoms did not change. Other than the swap,
we have not moved modems around.
Thanks for the MAC clue. It could have been an impediment.
"GbH" wrote:
.
"Lem" <lemp40@unknownhost> wrote in message
news:eCoehGoJKHA.6016@xxxxxxxxxxxxxxxxxxxxxxx
dbir wrote:
In case anyone is following this, here are today's developments:I don't know if it's the cause of your problems, but it appears as if
Took my neighbor's problem computer to my house and connected it
directly to my Roadrunner modem. His computer accessed the internet
OK without problems.
Took my healthy computer to my neighbor's house and connected it
directly to his Roadrunner modem. Got the same problem symptoms (can
connect, receive IP address from DHCP, and receive addresses of DNS
servers, but cannot ping nor access the DNSs nor anything beyond the
Default Gateway).
Spent a few hours on phone with Time Warner (Roadrunner) level 1, 2,
and 3 support trying lots of things, even swapping out the (new)
cable modem (desperate). Nothing worked.
We are about to give up, with my neighbor resigned to spending the
rest of his life on dial-up.
Any ideas?
Don
"dbir" wrote:
My neighbor finally took the plunge to upgrade from dial-up to
cable, but cannot access the internet through it. He's using XP
Home, directly connected to cable modem - service by Time Warner,
which works fine for me next door. His dial-up continues to work
fine, but access through his Ethernet local area connection does
not. TW confirmed (with their own laptop) that the connection &
modem are good, so problem must be in his computer.
Network Diagnostics shows pings to his IP, Default Gateway, and DHCP
Server work, but pings to DNS servers fail. Verified manually
(pings to those DNS from my computer work, so it's not the DNS
themselves). Pings to other IPs (e.g., Google's) also fail.
Connection's Status shows lots of packets sent, but almost none
received. Uninstalled Norton 360 with no effect. No other security
software present, Windows Firewall turned off. TCP/IP properties
and IP addresses received (DNS, DHCP) look fine (same external IP
addresses my computer gets).
Other things checked:
Boot in Safe Mode yields same results. Device Manger shows no
problems with Network Adapter or (hidden) TCP/IP drivers. Packet
Filtering is off. All Windows components (needed or not) are
installed, all services (needed or not) are started or on auto.
Windows SFC ran OK.
From all the sage advice I found on this board, here's what I've
tried (without success):
reset TCP/IP (netsh int ip reset)
turned off ipsec service (temp)
ipconfig /flushdns
ipconfig /registerdns
So: dial-up works fine, and Ethernet HW/SW gets as far as gateway &
DHCP, but can't get to DNS nor anything else.
I'm a bit over my head, and sure need some advice. Thanks.
your friend's computer has extraneous networking components installed.
The ipconfig results that you posted look like ipv6 is installed. It
shouldn't be for XP Home.
Unless TW requires these added features for some reason, if you go to
the properties of the network adapter, you should only see the
following 4 items (see
http://screenshots.leeindy.com/lac_general.shtml):
- Client for Microsoft Networks
- QoS Packet Scheduler [this is optional]
- File and Printer Sharing [this also is optional, and in the case of
a computer connected directly to the Internet probably should not be
installed without first installing a firewall]
- Internet Protocol (TCP/IP)
If uninstalling ipv6 from your friend's computer doesn't resolve
things, it might be instructive to post ipconfig /all results from
your computer when connected in your house.
Aside from the ipv6 issue, it really sounds as if there is a
misconfiguration at the TW end of your friend's connection.
To summarize for his next call to TW:
1. His computer doesn't connect in his house.
2. His computer does connect in your house.
3. Your computer does connect in your house.
4. Your computer doesn't connect in his house.
The above facts strongly suggest a defective or misconfigured cable
modem in your friend's house. However, if you have in fact tried a
second modem in your friend's house with the same results, the next
logical conclusion is a problem at the head end, but that doesn't
explain "TW confirmed (with their own laptop) that the connection &
modem are good."
--
Lem -- MS-MVP
Apollo 11 - 40 years ago:
http://www.nasa.gov/mission_pages/apollo/40th/index.html
Lot of ISPs use MAC addressing to limit hardware access to specific
(usually their own) units, sounds like it could be corrupt for the modem
at your friends house.
It will require a house call to set it right, or a new/replacement
preconfigured unit.
--
Wisdom and experience come with age, they say, but I wish I could
remember the darn question
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