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Contributor
galfam
Posts: 9
Registered: ‎10-08-2011

Can't connect to modem

I cannot connect to the Comcast modem on one of my computers. I own three computers for my family, a MacBook, a Dell running Windows 7, and a HP running Vista. The Mac and Dell both connect seamlessly, no problems. However, the HP cannot connect. The HP can connect to any other networks, at other locations such as my relatives, but it just cannot connect to my Comcast router/modem. I need help--It clearly isn't the computer, but I think it has something to do with Vista since the Windows 7 computer works fine. I really want to figure out what the problem is.

 

Thanks.

Silver Problem Solver
reasd
Posts: 6,127
Registered: ‎02-22-2007

Re: Can't connect to modem


galfam wrote:

I cannot connect to the Comcast modem on one of my computers. I own three computers for my family, a MacBook, a Dell running Windows 7, and a HP running Vista. The Mac and Dell both connect seamlessly, no problems. However, the HP cannot connect. The HP can connect to any other networks, at other locations such as my relatives, but it just cannot connect to my Comcast router/modem. I need help--It clearly isn't the computer, but I think it has something to do with Vista since the Windows 7 computer works fine. I really want to figure out what the problem is.

 

Thanks.

 

Hello,

You might have to call comcast 1-800 comcast and provide them with the mac address and or serial number of the modem?


 

Contributor
galfam
Posts: 9
Registered: ‎10-08-2011

Re: Can't connect to modem

I would just like to add:

I've followed the directions to connect to the modem on Vista, however I just get a local only connection. If I connect an ethernet cable to the modem, it works, but I cannot connect wirelessly.

Connection Expert
EG
Posts: 42,184
Registered: ‎12-24-2003

Re: Can't connect to modem

[ Edited ]

Are you entering the wireless security password of the gateway device in to the HP's config ?

Connection Expert
JamesR
Posts: 6,423
Registered: ‎09-29-2007

Re: Can't connect to modem


galfam wrote:

I would just like to add:

I've followed the directions to connect to the modem on Vista, however I just get a local only connection. If I connect an ethernet cable to the modem, it works, but I cannot connect wirelessly.


"Local Only" sounds like you are not pulling an IP address from the DHCP server.

1.Click on Start > Run amd type "cmd" in the Run box.
2.At the Blinking Cursor, type "ipconfig /all" and hit enter.
3.Use your mouse and Highlight the information from step 2 and hit enter (This will copy the info to your clipboard)
4.Open up a new post here in your thread and use ctrl v or right click and paste the information into the post
This will give some information so we can see whats up

Connection Expert
JamesR
Posts: 6,423
Registered: ‎09-29-2007

Re: Can't connect to modem

If you do the Ipconfig /alll as above and get an IP address starting with 169.254.x.y then there is either a bad connection, bad drivers or a bad IP stack

 

You could do this series of commands at the Dos Prompt
netsh int ip reset log.txt
ipconfig /flushdns
ipconfig /registerdns
netsh winsock reset
shutdown /r

The above sequence will restack ip, Flush and reregister the dns cache, do the winsock fix and restart your PC.

Contributor
galfam
Posts: 9
Registered: ‎10-08-2011

Re: Can't connect to modem

[ Edited ]

Double post...

Contributor
galfam
Posts: 9
Registered: ‎10-08-2011

Re: Can't connect to modem

Here it is.

 

Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Users\Jack>ipconfig/all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : Jack-PC
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Mixed
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No

Wireless LAN adapter Wireless Network Connection:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Atheros AR5007 802.11b/g WiFi Adapter
   Physical Address. . . . . . . . . : 00-24-2B-56-F1-2C
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::cc72:31fb:bcce:d903%11(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.1.39(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Saturday, October 08, 2011 6:56:11 PM
   Lease Expires . . . . . . . . . . : Sunday, October 09, 2011 6:56:11 PM
   Default Gateway . . . . . . . . . : 192.168.1.1
   DHCP Server . . . . . . . . . . . : 192.168.1.1
   DNS Servers . . . . . . . . . . . : 192.168.1.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Local Area Connection:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Realtek RTL8102E Family PCI-E Fast Ethern
et NIC (NDIS 6.0)
   Physical Address. . . . . . . . . : 00-1F-16-61-62-7C
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 6:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 7:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 11:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 02-00-54-55-4E-01
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:34af:1b0b:3f57:fdfb(Pref
erred)
   Link-local IPv6 Address . . . . . : fe80::34af:1b0b:3f57:fdfb%12(Preferred)
   Default Gateway . . . . . . . . . : ::
   NetBIOS over Tcpip. . . . . . . . : Disabled

C:\Users\Jack>

Connection Expert
JamesR
Posts: 6,423
Registered: ‎09-29-2007

Re: Can't connect to modem

OK the 192.168.1.34 address says you have a good connection to the router If you ping the moem from the Command prompt ping 152.168.100.1 that would say you can get through the Router. If then you do a tracert yahoo.com again at the command prompt and paste it back here we could see whether you can reach out into the internet.
Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: Can't connect to modem

It appears to be talking to the router just fine.  It has pulled what looks like a valid IP address, it's DHCP server, default gateay, and DNS servers all appear to be normal and just as you would expect from a typical router wireless connection.

 

What exactly doesn't work?  Be very specific and include complete error messages.

 

Does your router have MAC filtering enabled?  If so, be sure to add the wireless MAC address (ie. 00-24-2B-56-F1-2C) to the list on the router.

Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: Can't connect to modem


JamesR wrote:
OK the 192.168.1.34 address says you have a good connection to the router If you ping the moem from the Command prompt ping 152.168.100.1 that would say you can get through the Router. If then you do a tracert yahoo.com again at the command prompt and paste it back here we could see whether you can reach out into the internet.


That should be 192.168.100.1. ;-)

 

Contributor
galfam
Posts: 9
Registered: ‎10-08-2011

Re: Can't connect to modem

Okay, I'm going to try this again. I'm going to paste in the ipconfig again because I'm wondering if I was somehow accidently connected to another modem in the area.

 

Ipconfig:

Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Users\Jack>ipconfig/all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : Jack-PC
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Mixed
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No

Wireless LAN adapter Wireless Network Connection:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Atheros AR5007 802.11b/g WiFi Adapter
   Physical Address. . . . . . . . . : 00-24-2B-56-F1-2C
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::cc72:31fb:bcce:d903%11(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.1.39(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Saturday, October 08, 2011 6:56:11 PM
   Lease Expires . . . . . . . . . . : Sunday, October 09, 2011 8:49:11 PM
   Default Gateway . . . . . . . . . : 192.168.1.1
   DHCP Server . . . . . . . . . . . : 192.168.1.1
   DNS Servers . . . . . . . . . . . : 192.168.1.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Local Area Connection:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Realtek RTL8102E Family PCI-E Fast Ethern
et NIC (NDIS 6.0)
   Physical Address. . . . . . . . . : 00-1F-16-61-62-7C
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 6:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 7:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 11:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 02-00-54-55-4E-01
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

C:\Users\Jack>

 

And, here is the tracert of yahoo.com:

Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Users\Jack>tracert yahoo.com
Unable to resolve target system name yahoo.com.

C:\Users\Jack>

 

I don't know if anything changed, I think I was in fact connected to some other modem somehow...

 

Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: Can't connect to modem

[ Edited ]

Try tracert to the actual IP address, like:

 

   tracert 98.137.149.56

 

If that works, your issue is a DNS problem.  Try running

 

   ipconfig /flushdns 

 

If that doesn't work, you can try rebooting your router.  If still not go, go into your computer's TCP/IP properties and override the DNS setting from automatic to 75.75.75.75 and 75.75.76.76.  Those are the Comcast anycast DNS servers.  Any better?  If so, then there is likely some problem with the dns proxy running on the router, check the actual DNS servers configured on the router's WAN interface, what are they?

Contributor
galfam
Posts: 9
Registered: ‎10-08-2011

Re: Can't connect to modem

The tracert of the IP never went through, it just said it couldn't connect.

Gold Problem Solver
BruceW
Posts: 6,948
Registered: ‎12-03-2007

Re: Can't connect to modem

[ Edited ]

galfam wrote: The tracert of the IP never went through, it just said it couldn't connect.

Details are important. Please post the text of the error message. Also note that the command Baric posted had a stray character that would likely cause an error (the Forum editor throws these in now and then). Please try these commands and post the results:

 

    tracert 98.137.149.56

 

    tracert www.yahoo.com

Contributor
galfam
Posts: 9
Registered: ‎10-08-2011

Re: Can't connect to modem

Here are the results:

 

Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Users\Jack>tracert 98.137.149.56

Tracing route to 98.137.149.56 over a maximum of 30 hops

  1     *        *     Jack-PC [192.168.1.39]  reports: Destination host unreach
able.

Trace complete.

C:\Users\Jack>tracert www.yahoo.com
Unable to resolve target system name www.yahoo.com.

C:\Users\Jack>

Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: Can't connect to modem

Odd.  So what we have here is a Vista SP1 system that can get a wireless IP address (so it's obviously talking to the router), but then other connections fail to use that interface or the router fails to respond.  Not DNS issue, but a more basic IP routing issue.  What does route print say?  If you direct connect the Vista system to the router using an ethernet cable, does it work now?  If so, what is the tracert to google.com say?  What about route print again?

 

What exact wireless router are you using?  Is it using MAC filtering or are access control rules in effect?  What does the list of wireless clients say?  What about DHCP clients?

 

Your OS is downlevel on maintenance, I would recommend you install Vista Service Pack 2.  Just run Windows Update, it should find it for you.

Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: Can't connect to modem


BruceW wrote:

Details are important. Please post the text of the error message. Also note that the command Baric posted had a stray character that would likely cause an error (the Forum editor throws these in now and then). Please try these commands and post the results:

 

    tracert 98.137.149.56

 

    tracert www.yahoo.com



Stray character?  Be glad to go and fix it, but I don't see it and copy/paste directly into a Command Prompt seems to work fine here...

Gold Problem Solver
BruceW
Posts: 6,948
Registered: ‎12-03-2007

Re: Can't connect to modem


Baric wrote: Stray character?  Be glad to go and fix it, but I don't see it and copy/paste directly into a Command Prompt seems to work fine here...

On my WinXP system the tracert command in message 13 looks like this in IE and Firefox:

Tracert1.png

And if I copy the whole line including that little dingus after the 6 into a CMD window, I get this:

 

    C>tracert 98.137.149.56?
    Unable to resolve target system name 98.137.149.56?.

 

I figured the OPs problem was weird enough without additional weirdness from the Forum editor.

Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: Can't connect to modem

[ Edited ]

Weird, I don't see that here on Win7 with Firefox 7.0.1, pastes into the prompt without issues.  Well, if you get something like that, just delete the last stray character, it clearly doesn't belong.

 

EDIT: After trying various ways of selecting the text, I was able to reproduce this when pasting into the Command Prompt, but I had to swipe select the text way out past the end of the line.  It appears that the generated HTML for the page has some kind of whitespace after the end of the IP address but before the ending strong and font tags.  The post editor doesn't see it, paste into notepad doesn't see it, the displayed page doesn't show it, but something is there.  It shows up in the Win7 Command Prompt an empty rectangle, which is just the standard glyph for something undisplayable.  A similar substitution happens in Codewright.  So I went and recreated that line in the post and it seems to be gone now.  No clue how it happened, but since it appears to be gone now, I guess I won't worry about it... too much.

Contributor
galfam
Posts: 9
Registered: ‎10-08-2011

Re: Can't connect to modem

[ Edited ]

Here is the route print:

Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Users\Jack>route print
===========================================================================
Interface List
 11 ...00 24 2b 56 f1 2c ...... Atheros AR5007 802.11b/g WiFi Adapter
 10 ...00 1f 16 61 62 7c ...... Realtek RTL8102E/8103E Family PCI-E FE NIC
  1 ........................... Software Loopback Interface 1
 13 ...00 00 00 00 00 00 00 e0  Microsoft ISATAP Adapter
 14 ...00 00 00 00 00 00 00 e0  Microsoft ISATAP Adapter #2
 12 ...02 00 54 55 4e 01 ...... Teredo Tunneling Pseudo-Interface
===========================================================================

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1     192.168.1.39     25
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306
      192.168.1.0    255.255.255.0         On-link      192.168.1.39    281
     192.168.1.39  255.255.255.255         On-link      192.168.1.39    281
    192.168.1.255  255.255.255.255         On-link      192.168.1.39    281
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306
        224.0.0.0        240.0.0.0         On-link      192.168.1.39    281
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306
  255.255.255.255  255.255.255.255         On-link      192.168.1.39    281
===========================================================================
Persistent Routes:
  None

IPv6 Route Table
===========================================================================
Active Routes:
 If Metric Network Destination      Gateway
 12     18 ::/0                     On-link
  1    306 ::1/128                  On-link
 12     18 2001::/32                On-link
 12    266 2001:0:4137:9e76:408:2308:3f57:fdfb/128
                                    On-link
 11    281 fe80::/64                On-link
 12    266 fe80::/64                On-link
 12    266 fe80::408:2308:3f57:fdfb/128
                                    On-link
 11    281 fe80::cc72:31fb:bcce:d903/128
                                    On-link
  1    306 ff00::/8                 On-link
 12    266 ff00::/8                 On-link
 11    281 ff00::/8                 On-link
===========================================================================
Persistent Routes:
  None

C:\Users\Jack>

 

Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: Can't connect to modem

Those routes look perfectly normal.  What about the other questions?

Contributor
galfam
Posts: 9
Registered: ‎10-08-2011

Re: Can't connect to modem

I'm pretty good at the rest of computers, but I don't know anything about networking. I don't know how to get the rest of the info he was asking...

Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: Can't connect to modem


galfam wrote:

I'm pretty good at the rest of computers, but I don't know anything about networking. I don't know how to get the rest of the info he was asking...


Did you direct your computer to the router with an ethernet cable and try again?  Same commands.  This will tell us if this is a wireless only problem.

 

What router are you using?  We need the exact model number to give specific instructions.  If you login into your router at http://192.168.1.1 , somewhere in that interface is a setting for MAC filtering or access restrictions.  If this is turned on and your computer's wireless MAC address (ie the line called Physical Address in the ipconfig output) is NOT listed, the router will not talk to your computer.

 

What does the list of wireless clients say?  Again, somewhere on that interface is a way to get the list of connected wireless systems, and likely DHCP clients as well.  Go in there and poke around, find out where stuff is and post back.

 

As I said before, have you updated your operating system?  You are using SP1, but the SP2 is the latest, I would recommend you install Vista Service Pack 2.  Just run Control Panel -> Windows Update, it should find it for you.  If it doesn't just follow the link I provided for a way to download it explicitly.