Valhalla Legends Forums Archive | General Discussion | Network Problems

AuthorMessageTime
iago
I suspect this is a case of hardware failure, but I'd like to make sure.

I plugged my laptop into my hub at work that I always use, and I can do the dhcp just fine (I get my good ol' ip address), but after that, I can't connect to any other computer (on or outside the network) on any port (ping to or from, http, etc). Any idea what this can be? I just find it weird that dhcpcd would work, but nothing else will.

Thanks!
April 8, 2004, 2:00 PM
Adron
Can you ping the dhcp server? Might you be firewalled? Some local firewall that drops all packets?

I don't see why dhcp would work and not other packets. A dhcp request should be similar to a ping - short packet and short reply. Do you have access to packet capturing on both sides of the hub? Do you see activity on the lights?

Some time I've had a cable with a bad connection where it could transmit so-so, single-duplex. That could cause problems a bit like what you're describing, a packet would get through now and then, but when there was a lot of traffic it would just break down.
April 8, 2004, 2:11 PM
iago
I can't ping 192.168.1.1, and I *think* that's the dhcp server, but I'm not entirly sure.

When I ping, the light on my hub DOES blink, butr I still get "Destination Host Unreachable" for everything. The odd thing is, my hub is sitting *right here*. I can 3 plugs in it, one goes to my desktop (*waves*), one goes to my laptop, and one goes to the wall. My desktop is fine, but can't ping my laptop, my laptop can't ping anything.
April 8, 2004, 2:18 PM
Adron
Run ethereal in promiscous mode on your desktop and see if you see the pings from your laptop. Run ethereal on your laptop in promiscous mode on your laptop and see if you get the pings from your desktop. It is a hub, right, not a switch?

Look at the link lights for your connection on *both* the hub and the laptop. If only one is on, you have a cable that is broken one way. Look for any unusual blinking too. Verify that your laptop isn't configured for full duplex if the hub doesn't support that, or reverse.

Running a full duplex connection to a hub will cause instant collisions 99% of the time, and crap network performance.

April 8, 2004, 2:21 PM
iago
Bah, I have to stop the radio to check lights :P

The laptop was working before, so I'm reasonably sure the configuration is correct.

I can't do ethereal on my desktop (I'm not an admin, it's a work computer) but I can try on my desktop.

When I ping my desktop with my laptop, the desktop/network lights blink, but the desktop light doesn't.

When I ping my laptop with my desktop, the desktop/network lights blink.

When I ping out from my laptop with ethereal going, only ARP goes out, "Who has 192...[desktop]? Tell 192..[me]" and nothing comes back.

My laptop with Ehtereal running doesn't see any network traffic to/from my desktop.

I tried changing the port on the hub that the laptop's plugged into with no avail.
April 8, 2004, 2:29 PM
iago
Also, when I'm not doing anything with my laptop, there is no constant light, but when I try to do something I get a blinking light. The other two connections have blinking lights.

I also tried unplugging the hub.
April 8, 2004, 2:35 PM
Adron
[quote author=iago link=board=2;threadid=6206;start=0#msg54008 date=1081434593]
Bah, I have to stop the radio to check lights :P
[/quote]

Have to stop the radio? You can't see the lights without moving things away?


[quote author=iago link=board=2;threadid=6206;start=0#msg54008 date=1081434593]
The laptop was working before, so I'm reasonably sure the configuration is correct.
[/quote]

I'm not convinced that you're actually getting an ip from the dhcp server. Perhaps you're just keeping your old one (from a long lease), or perhaps you're getting one from microsoft's range.

Can you ethereal while doing ipconfig /renew and see that you're actually getting traffic from the dhcp server?

[quote author=iago link=board=2;threadid=6206;start=0#msg54008 date=1081434593]
I can't do ethereal on my desktop (I'm not an admin, it's a work computer) but I can try on my desktop.

When I ping my desktop with my laptop, the desktop/network lights blink, but the desktop light doesn't.

When I ping my laptop with my desktop, the desktop/network lights blink.
[/quote]

I'm confused about your use of the word "desktop" here. Do you have a rx and a tx light on your desktop's network card? If so, can you see the rx light blink on your desktop when you ping from your laptop?

Can you see any hub lights blink when you ping from the laptop?

[quote author=iago link=board=2;threadid=6206;start=0#msg54008 date=1081434593]
When I ping out from my laptop with ethereal going, only ARP goes out, "Who has 192...[desktop]? Tell 192..[me]" and nothing comes back.

My laptop with Ehtereal running doesn't see any network traffic to/from my desktop.

I tried changing the port on the hub that the laptop's plugged into with no avail.
[/quote]

Try reversing the cable between hub and laptop. If that doesn't allow you to receive (ethereal) data from the network on your laptop, it would seem like your network card in your laptop is broken. At least the receive line and possibly the transmit too.

Perhaps some connector isn't ok? I've had 3com pcmcia cards where the small cable from pcmcia connector to rj45 slot broke. They were pretty fragile.
April 8, 2004, 2:39 PM
Adron
[quote author=iago link=board=2;threadid=6206;start=0#msg54009 date=1081434916]
Also, when I'm not doing anything with my laptop, there is no constant light, but when I try to do something I get a blinking light. The other two connections have blinking lights.

I also tried unplugging the hub.
[/quote]

Is there no constant light on the other connections either?

There's typically a constant link light that goes on when the hub establishes a connection with the laptop. There are "link packets" being transmitted all the time just to keep the connection going, and when those are being received ok, the link lights go on at each end.
April 8, 2004, 2:42 PM
iago
Well with vL radio going, the light constantly blinks.

I should have mentioned I'm on linux, and "dhcpcd -d eth0" definately retries getting my ip.

When I say blinking lights, I always mean on the hub.

I get the exact same error after reversing the cable. Sounds like the NIC? It's given me problems before but it's always worked at.. work. I have a usb one, but it's at home. I don't like the idea of going the full day with no network from laptop, but I guess I'll survive :)
April 8, 2004, 2:57 PM
iago
[quote author=Adron link=board=2;threadid=6206;start=0#msg54011 date=1081435328]
[quote author=iago link=board=2;threadid=6206;start=0#msg54009 date=1081434916]
Also, when I'm not doing anything with my laptop, there is no constant light, but when I try to do something I get a blinking light. The other two connections have blinking lights.

I also tried unplugging the hub.
[/quote]

Is there no constant light on the other connections either?

There's typically a constant link light that goes on when the hub establishes a connection with the laptop. There are "link packets" being transmitted all the time just to keep the connection going, and when those are being received ok, the link lights go on at each end.
[/quote]

Sorry, I meant that the 2 connectors have constant "Link" lights, but the laptop's one doesn't. It just has the flickering Rx light when it tries to do stuff.
April 8, 2004, 2:58 PM
Adron
[quote author=iago link=board=2;threadid=6206;start=0#msg54015 date=1081436310]
Sorry, I meant that the 2 connectors have constant "Link" lights, but the laptop's one doesn't. It just has the flickering Rx light when it tries to do stuff.
[/quote]

If you don't get a Link light, that's a strong indication of a problem. The link light should go on as soon as the card is activated, whether it has an IP or not. Since you've changed the cable and the hub with no effect, it's now time to change your laptop ;)

Have you ever had random problems before? It could be just a bent pin in the slot... But then, that would be likely to work a bit sometimes. Maybe you'll have to get a new nic for your laptop.
April 8, 2004, 3:12 PM
iago
Well, I know there's a screwed up pin. You might remember I posted awhile ago about it. But so far at work it has *never* given me a problem, I suspect it's because I'm using a straight cable instead of crossover. I do have a USB one which I use at home, but I stopped bringing it when I realized it worked 100% here. Well, till today :)

I guess is one of those, "You'll get over it" situations :)
April 8, 2004, 3:48 PM
Adron
Straight cable or crossover cable makes no difference. Which pin was it again?

edit: I vaguely recall you not wanting to open it up and resolder the pin... Maybe it's time to do that now ;)
April 8, 2004, 3:50 PM
iago
[quote author=Adron link=board=2;threadid=6206;start=0#msg54031 date=1081439440]
Straight cable or crossover cable makes no difference. Which pin was it again?

edit: I vaguely recall you not wanting to open it up and resolder the pin... Maybe it's time to do that now ;)
[/quote]

Or maybe it's time to start bringing my usb NIC with me :P

It's the first pin on the right:

[code]|||||||\[/code]
April 8, 2004, 4:27 PM
Adron
[quote author=iago link=board=2;threadid=6206;start=0#msg54037 date=1081441621]
Or maybe it's time to start bringing my usb NIC with me :P

It's the first pin on the right:

[code]|||||||\[/code]
[/quote]

The pins in use are 1, 2, 3 and 6 if i remember correctly. It seems that you've managed to bend pin 1. Hmm. I don't remember now, how badly bent was it? Might it have been making contact before and not now?
April 8, 2004, 5:45 PM
iago
[quote author=Adron link=board=2;threadid=6206;start=0#msg54054 date=1081446359]
[quote author=iago link=board=2;threadid=6206;start=0#msg54037 date=1081441621]
Or maybe it's time to start bringing my usb NIC with me :P

It's the first pin on the right:

[code]|||||||\[/code]
[/quote]

The pins in use are 1, 2, 3 and 6 if i remember correctly. It seems that you've managed to bend pin 1. Hmm. I don't remember now, how badly bent was it? Might it have been making contact before and not now?
[/quote]

It's not really bent so much as it's loose. I can move it about 2mm in either direction.

It's been working with a straight cable but not with crossover for some time, so I just assumed that pin 1 (I assume you count from the right?) was only used by crossovers.
April 8, 2004, 5:54 PM
Adron
[quote author=iago link=board=2;threadid=6206;start=15#msg54059 date=1081446898]
It's not really bent so much as it's loose. I can move it about 2mm in either direction.

It's been working with a straight cable but not with crossover for some time, so I just assumed that pin 1 (I assume you count from the right?) was only used by crossovers.
[/quote]

The same pins are used by both straight and crossover cables.

Straight : 1 - 1, 2 - 2, 3 - 3, 6 - 6
Cross-over : 1 - 3, 2 - 6, 3 - 1, 6 - 2

Whether you count from the right or from the left depends on how you hold the plug.... :P

Google points to some illustrative images, such as this one.
April 8, 2004, 6:01 PM
iago
hmm, it's odd that it worked fine with straight and not with crossover, then. Perhaps there's some property (how #1 is used?) that is breaking it..
April 8, 2004, 6:42 PM
Adron
[quote author=iago link=board=2;threadid=6206;start=15#msg54074 date=1081449729]
hmm, it's odd that it worked fine with straight and not with crossover, then. Perhaps there's some property (how #1 is used?) that is breaking it..
[/quote]

No, they're used the same way. It's more likely that one of your cables has a slightly different connector, perhaps it's 0.5 mm longer or something like that.
April 8, 2004, 6:50 PM
iago
[quote author=Adron link=board=2;threadid=6206;start=15#msg54075 date=1081450231]
[quote author=iago link=board=2;threadid=6206;start=15#msg54074 date=1081449729]
hmm, it's odd that it worked fine with straight and not with crossover, then. Perhaps there's some property (how #1 is used?) that is breaking it..
[/quote]

No, they're used the same way. It's more likely that one of your cables has a slightly different connector, perhaps it's 0.5 mm longer or something like that.
[/quote]

hmm, I've tried with 2 different straight (which work) and 2 different cross (which don't work). Weird coincidence?
April 8, 2004, 7:54 PM
Adron
[quote author=iago link=board=2;threadid=6206;start=15#msg54086 date=1081454045]
hmm, I've tried with 2 different straight (which work) and 2 different cross (which don't work). Weird coincidence?
[/quote]

Hmm, sounds like it... What about trying a cross-over cable to the hub's uplink port?
April 8, 2004, 7:58 PM
mynameistmp
Have you tried using the laptop at home ?
April 11, 2004, 7:36 AM
iago
[quote author=mynameistmp link=board=2;threadid=6206;start=15#msg54524 date=1081668982]
Have you tried using the laptop at home ?
[/quote]

aah, THAT'S what you were talking about on irc. Sorry, i was in a game, didn't get your messages till you were offline.

Anyway, the NIC has never worked at home (well, not in a long time, since the pin got broken), but has always worked at work. I've always assumed it was because of the difference in cables. At home I use a USB NIC (Xar says it sucks, but whatever).
April 11, 2004, 8:59 AM
MrRaza
Use a cable tester.
April 13, 2004, 7:55 AM
iago
[quote author=MrRaza link=board=2;threadid=6206;start=15#msg54913 date=1081842951]
Use a cable tester.
[/quote]
I doubt it's a problem with the cable.


Anyway, I came to work today and plugged it in to test, and now it works. The link light is on and I can dhcp/ping/whatever in or out of the network. So I don't know what happened on Friday, but I'm going to to not to jinx it :)
April 13, 2004, 1:06 PM

Search