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jimkyle
Btrieve Guy
Premium Member
join:2002-10-20
Oklahoma City, OK

jimkyle

Premium Member

[Wired] DHCP to WinXP Pro system

I'm attempting to bring my systems back up after my ISP changed my account from true static IPs to PPPoE sticky "static" addresses. After two hours on the phone with Tier 2 tech support I finally got one box back on line, but am completely unable to get a second one going. Both were working perfectly before the changeover.

The hardware is a SpeedStream 4100B modem (in bridged mode) and a WRT54G router, set up for PPPoE. It's wired to a box running Xubuntu 10.04 LTS, and to another running WinXP Pro SP3. Both boxes are up to date as of a week ago. There's also a wireless connection to an HP laptop, which is seldom powered up. The router is configured to be a DHCP server handing out addresses in the range 192.168.1.100 to 192.168.1.149.

The Linux box is working perfectly; it's pulling an address of 192.168.1.101 (the "100" IP was assigned to the laptop, which I used for initial configuration of the router) and I'm using it to post this problem.

However the WinXP box is unable to get any IP at all; it reports that it is unable to connect to the 192.168.1.1 router address that I've configured as its gateway. Specifically it says it's on a different subnet.

The router's front-panel lights indicate that it is seeing the WinXP system's attempt to connect, but I find nothing in the status report. I've configured the XP's Windows Firewall to allow DHCP traffic on port 67, both TCP and UDP.

What else should I do to attempt to pin down the problem and regain connectivity for the XP system?

wayjac
MVM
join:2001-12-22
Indy

wayjac

MVM

If you manually assigned a gateway ip the computer is not a dhcp client
I would have a close look at the tcp/ip info of the linux box that should provide a answer

jimkyle
Btrieve Guy
Premium Member
join:2002-10-20
Oklahoma City, OK

jimkyle

Premium Member

Actually the PPPoE authentication configured the router, and the DHCP client on the Linux box set the gateway to 192.168.1.1. Here's the /etc/interfaces file on the Linux box, with the old static info commented out:

iface eth1 inet dhcp
# iface eth1 inet static
# # pre-up /usr/sbin/ethtool -s eth1 autoneg off
# address 66.143.22.33
# netmask 255.255.255.248
# gateway 66.143.22.38
# metric 10

auto eth1

On the WinXP box, doing "ipconfig /renew" simply times out, saying that the server could not be reached. The Windows Network Diagnostics tool says that the DHCP attempt failed due to wrong subnet.

I'm fairly sure it's something in the configuration of the XP box, since I could never get it to communicate with my LAN before this problem hit. To get it on the Internet, I had to assign it one of the five true static IPs I had available. So far I have not been able to make any of the new sticky IPs work -- only the one given me by Tier 2 as the gateway seems to be usable! I don't think my WRT54G with its stock firmware can handle the situation properly, but I should be able to live with a single dynamic IP if I can ever get all the machines working...

Ken1943
join:2001-12-30
Brighton, CO

Ken1943 to jimkyle

Member

to jimkyle
One thing I would try, is to repair the 'stack' on the xp machine, a somewhat common problem. Google 'repair xp stack' which should get you some auto repair programs. I have done it a few times.

wayjac
MVM
join:2001-12-22
Indy

wayjac to jimkyle

MVM

to jimkyle
You should be able to use all machines with the gateway ip
Are the 5 usable and the gateway in the same subnet

When the user id is @static.sbcglobal.net the public ip will always stay the same
When the user id is @sbcglobal.net the public ip will be dynamic

NetFixer
From My Cold Dead Hands
Premium Member
join:2004-06-24
The Boro
Netgear CM500
Pace 5268AC
TRENDnet TEW-829DRU

1 edit

NetFixer to jimkyle

Premium Member

to jimkyle
If you have an IP address configured as the gateway for your WinXP box, that box is not using DHCP, and that is why the "ipconfig /renew" is not working.

Setup your WinXP PC's TCPIP properties to look like the image below, and it might have a chance of working.



As for using the static IP addresses, those will need to be manually setup in whatever boxes you want to use the static IP addresses, and you will need to use the gateway IP address that your ISP provided for that IP address block (if your WRT54G router supports being able to use non NAT public IP addresses from its LAN along with using private IP addresses on its LAN...not all residential/SOHO routers can do that). Alternatively if your WRT54G router supports it, you may be able to use 1-1 NAT to expose specific private LAN IP addresses to specific public IP addresses in your static IP block. You may need to get a new SOHO/business class router (or possibly use non-stock firmware for your WRT54G) to be able to use both private and public IP addresses on your LAN.

jimkyle
Btrieve Guy
Premium Member
join:2002-10-20
Oklahoma City, OK

jimkyle

Premium Member

said by NetFixer:

If you have an IP address configured as the gateway for your WinXP box, that box is not using DHCP, and that is why the "ipconfig /renew" is not working.

Nope, I didn't manually configure any gateway address when attempting to get an IP automatically. I did, later, try configuring the XP box manually to use 192.168.1.2 with gateway of 192.168.1.1, and did get it to connect -- but the router refused to respond at all. Additionally, the XP box then apparently did a DoS on the router! I had to pull its cable from the router in order for the Linux box to respond, and restore the router's configuration from an earlier backup to regain internet connectivity at all.

I'll search for "repair xp stack" on Google and see if anything there helps. If that fails I'll call out a pro network tech tomorrow to see if he can solve the problem.
said by NetFixer:

Setup your WinXP PC's TCPIP properties to look like the image below, and it might have a chance of working.

That's exactly the way it was set up when the Network Diagnostic Tool launched by "netsh diag gui" told me the connection failed because of an incorrect subnet. The tool also told me that "255.255.255.255" which was automatically used to search for DHCP servers was an invalid IP address...

The Tier 2 techs told me that my registration, with a "@sbcglobal.net" address, did not change -- which might be why I'm not seeing any signs of the five "usable" pseudo-static IPs. And although I've configured my dns2go account to use the new IP reported by my router, and am able to ping that domain successfully with almost no latency, it doesn't get any access to my private ftp server -- which was the whole reason for getting statics in the first place. I suspect that I'll switch to a single dynamic plan and get four times the speed for just over half the price!

I do appreciate the hints I've gotten so far. Hopefully I'll get that machine back on line soon so my wife has access to her email and tennis scores!

wayjac
MVM
join:2001-12-22
Indy

wayjac

MVM

said by jimkyle:

The Tier 2 techs told me that my registration, with a "@sbcglobal.net" address, did not change -- which might be why I'm not seeing any signs of the five "usable" pseudo-static IPs

Using the "@sbcglobal.net" address will result in a dynamic public ip address
Since you have a -S package you must change the address to "@static.sbcglobal.net" to use the static public ip block
It won't take 5 minutes to check this out

If you don't have a router that supports the static public ip block you'll only be able to use 1 public ip address

jimkyle
Btrieve Guy
Premium Member
join:2002-10-20
Oklahoma City, OK

jimkyle

Premium Member

So where should I make this change? I can change it in the router setup easily enough, but does it also need changing at the AT&T registration page?

I'm okay with the idea of using only one public IP; that was all I needed in the first place but a block of five was the smallest I could get (and I understand the reason for that). Two of my previous five were never used.

Looks as if I need to get much more familiar with the WRT54G and the alternate firmware packages for it, or perhaps replace it with a more capable unit. Up until now it simply served as the wifi access point for my laptop and any machines brought in by friends and relatives. It still has its original firmware, which may be part of the problems I'm experiencing (in addition to the XP inability to connect, I don't seem to be able to get incoming connections to my private FTP server).

wayjac
MVM
join:2001-12-22
Indy

wayjac

MVM

said by jimkyle:

So where should I make this change? I can change it in the router setup easily enough

You just change the pppoe login from
@sbcglobal.net to @static.sbcglobal.net both are valid and you can switch them at your will

You do not need to go to the att registration page
said by jimkyle:

I'm okay with the idea of using only one public IP

The static login will get 1 ip from your block

said by jimkyle:

Looks as if I need to get much more familiar with the WRT54G and the alternate firmware packages for it, or perhaps replace it with a more capable unit

Do you have any other adsl routers

jimkyle
Btrieve Guy
Premium Member
join:2002-10-20
Oklahoma City, OK

jimkyle

Premium Member

Nope, this is the only one I have. It looks as if I may need the 3347 in order to take full advantage of the five statics. However I'll change the login and see whether I can get along with just one before ordering another router; if I can, then double the speed for half the price looks like a no-brainer and I'll change my plan accordingly!

Many thanks for the help! It's been a crash course in not very well documented areas.

wayjac
MVM
join:2001-12-22
Indy

wayjac

MVM

Here's a couple faq links that may be of help

5 Static IP-Compatible Routers
Info on the 5 Static IP packages

jimkyle
Btrieve Guy
Premium Member
join:2002-10-20
Oklahoma City, OK

jimkyle

Premium Member

VERY helpful. Thanks again!

Called my favorite repair tech in this afternoon and we ran quite a few tests. He found a bad cable, which is almost undoubtedly the reason the XP box would not connect (although it was working just fine until the IPs changed). The bad news is that the bad part is a 75-foot run in the attic that I'm not willing to have replaced. The good news is that adding a wifi dongle ought to restore connectivity to the XP box.

The only remaining serious problem at this point is how to get port forwarding through the WRT54G to the specific Linux box that runs my FTP server. It needs to handle ports 20 and 21, plus 51200-51299 for the passive FTP connections required. With that, I should be able to get rid of the -S plan in favor of a faster dynamic one. So far I've not found a WRT54G manual or user guide on the net, and my printed copy has long since vanished.

wayjac
MVM
join:2001-12-22
Indy

wayjac

MVM

said by jimkyle:

I should be able to get rid of the -S plan in favor of a faster dynamic one

All the -S plans are $45.00 a month
said by jimkyle:

The only remaining serious problem at this point is how to get port forwarding through the WRT54G to the specific Linux box that runs my FTP server

This link may help
Setting up an FTP server behind a Linksys Router
bennor
Premium Member
join:2006-07-22
New Haven, CT

1 edit

bennor to jimkyle

Premium Member

to jimkyle
You can find the router's user guide on the Cicso support website. You will need to enter your router version then select Downloads to find the User Guide.
»homesupport.cisco.com/en ··· s/WRT54G

I tried many years ago to get the 5 static IP's with AT&T (SBC at the time) DSL to work properly with stock Linksys WRT54G firmware. Never could get it to work right.

One option is to run 3rd party firmware like DD-WRT on the WRT54G and use "IPTables" via the command line in DD-WRT to assign the static public IP's. Here is one link that details how to configure multiple static IP's with a WRT54G running DD-WRT.
»www.wrtrouters.com/guide ··· ipleips/

I no longer have the -S DSL plan but do run a WRT54G V6 with DD-WRT build 14929 (micro) since the stock Linksys firmware is so limited.

Edit to add: Another way to add iptables in DD-WRT is via the Administrator command entry field. This link explains the process.
»www.techenclave.com/topi ··· -dd-wrt/

jimkyle
Btrieve Guy
Premium Member
join:2002-10-20
Oklahoma City, OK

jimkyle to wayjac

Premium Member

to wayjac
It definitely did. My line monitoring service is now showing zero packet loss. I've not yet been able to verify that the FTP server is accessible since all of my machines are now on this side of the router; I'll arrange for a friend locally to try to get into its anonymous oublic directory as a test.

I found different pricing on the AT&T web pages. One page showed the S plans at $45/month, but the "upgrade speed of existing plans" page said $55 for the 3 Mb/s Pro plan (and did not show me the Elite S plan at all). It also looked as if there's no contract requirement for new customers, but a 12-month contract is required for getting higher speed on an existing plan! I've been off contract since 2002 and don't really want to go back onto one...

Your advice has been invaluable. Thanks again for walking me through this minefield!

wayjac
MVM
join:2001-12-22
Indy

wayjac

MVM

said by jimkyle:

I've not yet been able to verify that the FTP server is accessible since all of my machines are now on this side of the router; I'll arrange for a friend locally to try to get into its anonymous oublic directory as a test

If you have a dialup modem it can be used to do the ftp log in
A network tools website and your firewall log can be used to ensure the ftp server is reachable
wayjac

wayjac

MVM

You never said if you tried using the @static.sbcglobal.net
If you did were you allocated a ip from your public ip block

NetFixer
From My Cold Dead Hands
Premium Member
join:2004-06-24
The Boro
Netgear CM500
Pace 5268AC
TRENDnet TEW-829DRU

NetFixer to wayjac

Premium Member

to wayjac
said by wayjac:

said by jimkyle:

I've not yet been able to verify that the FTP server is accessible since all of my machines are now on this side of the router; I'll arrange for a friend locally to try to get into its anonymous oublic directory as a test

If you have a dialup modem it can be used to do the ftp log in...

The 21st century equivalent of that (a tethered cellphone, or a smart phone with an ftp client) works well for external testing too.

jimkyle
Btrieve Guy
Premium Member
join:2002-10-20
Oklahoma City, OK

jimkyle to wayjac

Premium Member

to wayjac
said by wayjac:

You never said if you tried using the @static.sbcglobal.net
If you did were you allocated a ip from your public ip block

Yes, I'm using the static.sbcglobal.net address on the router login, but have not power cycled the modem itself. I HAVE had the router disconnect and reconnect, but got no change to the assigned address -- it still points to the "gateway" (7th of 8) address in the block. I'll try power-cycling the modem shortly and see if that makes it change.

I've now verified that the FTP server is accessible, having a friend use it from his home, so I now know what to do if I get the IP to change -- or I can live with it as-is for the present!

wayjac
MVM
join:2001-12-22
Indy

wayjac

MVM

said by jimkyle:

Yes, I'm using the static.sbcglobal.net address on the router login, but have not power cycled the modem itself

Ok thanks for confirming that the static login works
said by jimkyle:

I HAVE had the router disconnect and reconnect, but got no change to the assigned address -- it still points to the "gateway" (7th of 8) address in the block

This is normal and expected because you have a static ip block....If you change the router login username to @sbcglobal.net the router will be allocated a dynamic public ip address

jimkyle
Btrieve Guy
Premium Member
join:2002-10-20
Oklahoma City, OK

jimkyle

Premium Member

said by wayjac:

This is normal and expected because you have a static ip block....If you change the router login username to @sbcglobal.net the router will be allocated a dynamic public ip address

Nope, it's getting exactly the same IP address with either login string, and the assigned gateway is also the same. Adding "static" makes no difference at all. Either string is accepted, but that's the extent of its working.

I've also got some packet-loss issues that I'm pursuing with David in SBC Direct; they might possibly be related...

wayjac
MVM
join:2001-12-22
Indy

wayjac

MVM

said by jimkyle:

Nope, it's getting exactly the same IP address with either login string, Adding "static" makes no difference at all. Either string is accepted

The behavior you describe is not what I would expect
The -S package you have appears to work differently than the -S packages in my area, but if the public ip the router is allocated is always the same and is within the public ip block that is ok

NetFixer
From My Cold Dead Hands
Premium Member
join:2004-06-24
The Boro
Netgear CM500
Pace 5268AC
TRENDnet TEW-829DRU

NetFixer

Premium Member

said by wayjac:

said by jimkyle:

Nope, it's getting exactly the same IP address with either login string, Adding "static" makes no difference at all. Either string is accepted

The behavior you describe is not what I would expect
The -S package you have appears to work differently than the -S packages in my area, but if the public ip the router is allocated is always the same and is within the public ip block that is ok

Once again, AT&T proves that it is not really a monolith. In this area, a static IP block account is no longer required to add "static" to the login (although it I guess it is possible that they have changed back to that old rule since my retirement). The DSL router's WAN gets a dynamic IP address from the PPP server, and the customer must configure the LAN side of the router to use the static IP block addresses (either directly, or with 1-1 NAT).