Computer gets IP address from Router but cant ping router

Help Please, I have a D-Link DI-624 wireless Router with one Ethernet connected computer and a few wireless. I just set up a new computer in my workroom and connected to the wireless network/internet via a D-Link Ethernet bridge. I have. When I put the new computer in the family room and connected the router directly via Ethernet, I could not access or ping the router but when I do an IPconfig, I have an IP address and the correct gateway. I have done a /release & /renew which works but I still cannot connect when directly connected to the router. I can unplug the cable to the router, re hookup the Ethernet bridge and then have internet access. What gives here?

Merle-

Reply to
MC
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It's not clear if the DI-624 works with any of the other computers directly connected or via wireless.

I'll make a wild guess that you have two routes to the router from the new computah. One is direct with the LAN cable. The other is via wireless. These should show as two different IP addresses when you run IPCONFIG. However, the default route may not switch correctly between the two paths to the router. DHCP uses broadcasts, so it will work without a default route, but ping requires a route. Run: ROUTE PRINT to see the routeing table.

I've seen general weirdness with creative wiring problems caused by "split pairs" in the CAT5 cable. The usual result is that all the ethernet lights are correct, but data is erratic. I suggest you move the computah near the DI-624, and use a known good CAT5 cable to test the configuration. If that works, look for wiring screwups, staples in the cable, or mashed connectors.

There's also a very remote possibility that the address resolution table is screwed up when switching hardware devices. Run: ARP -A and make sure that the MAC address shown for the router's IP address belongs to the router and not the ethernet bridge or something else.

Also, dead DI-624 routers seem to appear in this newsgroups ocassionally. For example: |

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hope it's not a trend.

Reply to
Jeff Liebermann

Jeff, I have only one Ethernet port on the Computer in question and no wireless adapter. When I installed the OS (XP Pro) and did all the updates in an upstairs room, I used my D-Link Travel Router in "Client" mode so that I wouldn't have to install an actual wireless adapter in order to connect to the internet. When I moved it downstairs to the room with the wireless router, this computer was then "hard" wired to the router using the same Ethernet port as I had the "bridge" attached to. I powered everything off and restarted. I get the correct ip addresses but cannot ping or be pinged any other computer on my home network. I can still unplug the cable to the router, then plug the bridge back into the computer and bingo, all is well again. I will try some of the ideas that you suggested. Merle-

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I hope it's not a trend.

Reply to
MC

Easy. If it works with the client radio (a wireless bridge), and the computer has a clean install, and it doesn't work with the cable, then the only thing that's different is the CAT5 cable. I would check the cables, wiring, connectors, switch port[1], etc.

Incidentally, I keep a spare 300ft chunk of known good CAT5 around for such occasions. When I suspect that there's a cable problem, I replace it with my cable, and try again. If that works, I know for sure it's the cable or connectors. I've been fooled by my cheapo cable continuity tester more than once, and can't justify a proper but overpriced cable certifier.

[1] I have a 24 port managed ethernet switch at a customers with 4 blown ports. I've placed tape over the blown ports, warning labels, and told everyone not to use those ports. About once a year, I get a call with a connectivity problem when someone peeled off the tape, removed the warnings, ignored my admonitions, and plugged something into one of the blown ports. Sigh.
Reply to
Jeff Liebermann

Nope, not the cable. The cable was working and unplugged from the old computer and then plugged into the new one. I also tried a known good cable. I'm not a complete networking idiot that's why this is so strange.

Reply to
MC

Assumption, the mother of all screwups.

Well, if you juggling the connection between the working wireless client and the direct CAT5 connection, then it's possible that the router has the MAC address of the wrong interface for your setup. It will assign 192.168.1.xxx to the wireless connection. The ARP table in the router will show the MAC address of the wireless client. When you switch to the CAT5 cable, the router doesn't automagically clear the table. It still thinks it's talking to the wireless client. Eventually, it will time out and flush the ARP table, but it may be expedient to power cycle the router (and ethernet switch) after you juggle connections. Also, it won't hurt to flush the computer's ARP table with: arp -d 192.168.1.1 (the router's IP).

Try looking in the DI-624 log file to see if there are any useful error messages. The new computer might be sending garbage.

I still think it's the cable. I've never seen situations where a cable works with one machine and not another. However, I can see that it is possible to create a flaky cable that sorta works better with different machines by creating a split pair. These will not show up on a continuity tester, and require a CAT5/6 certifier to detect. It's often difficult to see the color stripes on the white wires, but perhaps a visual inspection will show something. Also, look for a wire that doesn't quite make it to the end of the connector. They tend to be intermittent.

What cinches it for me is that you can't see the other computers. If the DHCP deliverd IP address is valid, but the DI-624 is comatose or misconfigured, then internet access might be blocked, but you still should see the other machines. Try pinging them to be sure.

The only way to be sure is to replace the cable by dragging the computer near the router and plugging directly into the router with a known good patch cable.

Some other low probability guesswork worth checking are:

  1. Crud in the RJ45 connector on the new computer.
  2. Bent pins in the RJ45 connector on the new computer.
  3. NWAY failure caused by setting the protocol wrong on the ethernet port.
  4. Insufficient number of IP addresses in the DI-624.
  5. IP or MAC address filter set in DI-624 to block a connection.
  6. Firewall mis-configured in DI-624 to block traffic.
  7. XP Personal Firewall exceptions misconfigured. Turn it off for now.

I'm fairly sure it's not a computer config issue as the ethernet port can't tell the difference between a wireless bridged connection and a wired direct connection. If one works, so should the other.

Good luck.

Reply to
Jeff Liebermann

I did flush the ARP table, still no luck. Your other comments make sense and later today I will shut everything down for about 10 minutes then restart everything (DSL modem, Router, Then Computer) If I still have the same issue, I will try my old 802.11b router. That should eliminate any router problems.

Reply to
MC

I got the Same think the probme is the router DHCP work but the client can not use it i fixe a manual IP address and that fix the Problem

this is a bug on de di 624

Reply to
Midjet

Mac filtering is not enabled. previous post said that this problem may be a bug in the DI-624. I will try his suggestion and see what happens.

Reply to
MC

I setup my old DI524 router and everything works fine. The only difference between the older computer and the new one is the fact that the new one has a Marvel Mbit Ethernet adapter.

Reply to
MC

Do you have MAC filtering enabled? If so, make sure that the MAC address of the device in question is listed. If MAC filtering is enabled and the device is not listed then it won't be able to access your network.

Reply to
Doug Jamal

Problem Solved- The solution was to change the settings for the network adapter from "Autosense" to 100mbps full duplex. When in Autosense, it had a problem negotiating a reliable connection to my router.

Reply to
MC

Welcome to the joy of 802.3 NWAY negotiation. |

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NWAY is suppose to do is start at the highest speed ethernet protocol and work its way down to the slowest. It doesn't do much of a line test. If both ends of the link are capeable of 100baseT full duplex, then you have forced the fastest possible connection.[1] Your ethernet card and router do not have 100basetT4 capeability, so that's out. Therefore, the autosense negotiation should have stopped at

100baseTX FDX which is where you have manually set your router. In other words, if autosense was working, it would result in exactly the same setting.

If you had set your connection to 100baseTX HDX or perhaps 10baseT FDX/HDX, then there would certainly be cause for suspecting the wiring. However, with the automatic and manual setting ending up in the same place, methinks something is still fishy.

My guess(tm) is that that either NWAY negotiation on the new LAN card is broken, not on the router. Thats because the DI-624 worked just fine with the previous machine and its different LAN card. However, the new machine may not be doing a proper job of NWAY negotiation. The usual result is to end up with one end of the link in FDX while the other is in HDX modes. That will result in exactly the symptoms you're experiencing. You still have communications in both directions, but the flow control mechanism is broken.

I suggest you replace the PC's LAN card (if possible). I'm also curious as to the LAN cards make and model.

[1] The order and sequence is something like the following. I'm not 100% sure they're listed in the correct order. HDX = Half Duplex FDX = Full Duplex

(fastest) 100baseTX FDX 100baseT4 HDX 100baseTX HDX 10baseT FDX 10baseT HDX (slowest)

Reply to
Jeff Liebermann

It's always Something simple, isn't it? Glad you got it to work. Take care.

Reply to
Doug Jamal

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