• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 646
  • Last Modified:

Bizzare hub problem!

Hi all,

I have an ethernet LAN at home with my computer acting as server and 3 others connecting to my computer for internet. Recently, I purchased a new laptop and added it to the network.

The internet worked perfectly but then I noticed that the internet connection on one computer was disconnected and on another computer it worked sporadically, i.e. connection to a website was established 2-3 mins later.

There was a correlation between the sporadic computer and the new computer. If the new computer was idle, I could access the internet perfectly on the sporadic comp but then the internet connection on the new comp became sporadic and vice-versa.

I connected all the computers using a Linksys Ethernet hub which has 6 ports. One port is for uplink-which my computer uses as it is the server. Out of the remaining 5 'client' ports, 4 are now used. If I disconnect the new comp from the hub and the network, the internet on rest of the computers works perfectly.

I get a 1.1 Mbps broadband connection from my ISP and connect using a USB modem without any inbuilt router. I have also set the netword card speed to 100 mbps full duplex on each computer.

Each computer has the same DNS and is given an IP for the network using DHCP.How should I overcome the problem so that the internet connection is not compromised on any computer? Is it because I have used 4 out of the 5 available ports or it is something else? Do I need to buy a hub with 8-9 ports? Please advise. Thanks.
0
MastaBlasta
Asked:
MastaBlasta
  • 6
  • 3
  • 3
  • +7
1 Solution
 
ScotladCommented:
What kind of Linksys Router do you have ?  I had a similar issue with mine which is a BEFSR41.  I ended up going out an buying a new 8 port switch and it all works perfectly now.  I found I lost 2 of the ports though, but with switches being so cheap these days better just to get a new switch.

Hope this helps.
0
 
caball88Commented:
some hubs share the last 2 ports for uplink. if you select to use the uplink port, the adjacent port is no longer usable. so if you have 5 devices i would recommend getting a bigger siwtch. don't get another hub as they are in-efficient.
0
 
rshooper76Commented:
Are you having an IP conflict?  Make sure that all you devices have different IP addresses.  If this is not th case I woudl recommeng getting a new switch like caball88 suggested.
0
Concerto Cloud for Software Providers & ISVs

Can Concerto Cloud Services help you focus on evolving your application offerings, while delivering the best cloud experience to your customers? From DevOps to revenue models and customer support, the answer is yes!

Learn how Concerto can help you.

 
gjohnson99Commented:
How are you conect to the internet ? Hub/switch conected the internet connection the to your PCs?
0
 
moorhouselondonCommented:
I think that you would be best to shell out on a Broadband Router, rather than using a USB Modem.  Presumably you are using Internet Sharing software which isn't as good as presenting all pc's directly to the Internet, which is what you would do if you had a Router.
0
 
wyliecoyoteukCommented:
As caball88 says, some hubs share 2 ports, 1 is an uplink port for connecting to another hub or switch, and the other is a standard port. They are actually 2 connections to the same port , just wired differently.
This would mean you can only use 5 ports out of 6.
Alternatively, the end port may be autosensing uplink (not common on hubs), or have a switch to enable/disable uplink.

However, it is more likely to be a windows XP issue.
What version of windows are the existing PCs running?

Turning off QOS in windowsxp network settings may help




0
 
benstoreyCommented:
If anything, i would say your best bet to do anything would be to just buy a 6-8 port switch, which is still very cheap, but will solve many of your problems, including things being slow...

getting a router instead of a modem would also greatly increase your speed..  especially since up to 5 computers are using it..
But of course, cost all comes into this, even tho these days you can get a decent router/switch all in one (4 port switch most common but can get 6 or 8 port easily).
0
 
MastaBlastaAuthor Commented:
Thanks for the responses guys. Some of you have said that some hubs actually have 2 ports for uplink. Thats fine but like I said I have a 5-port hub, plus one for uplink. So even if the 5th port adjacent to the uplink port is in reality an uplink port, I should still be able to connect the remaining 4 computers in theory, shouldnt I? Another point to note is that at the front of my hub, there are 5 lights. 1 for the uplink port and 4 for the other 4 ports. Did they forget to put in a light for the 5th port?


All 4 computers run Windows XP. Some have SP2 some dont.I am not using ICS. I am using the Sygate Network Manager. Basically, my computer is connected to the USB modem(which is connected to the phone line through microfilters to filter out the ADSL and the actual phone line). There is a cat 5 cable going from my computer into the uplink port of the hub and then there are 3 simultaneous CAT 5 cables going to the other computers(there are 4 now, 4th being the troublesome one..never had any problems earlier with 3 computers). I dial the internet connection and it gets distributed to all the other computers.

Some of you have mentioned routers. I dont think that will be feasible because AFAIK its impossible to connect a router to a USB modem. I could buy the all in one modem/router but I am not keen on that at the moment.

I hope this clears some of the questions you guys had about my network. So what would you guys advise me to do now? Here is the port numbering on the back of my hub:-

1  2  3  4  5      6
                     Uplink

So basically, 6 for uplink(5 as well as most of you have said uplink uses the adjacent port too). So technically I can still successfully connect 4 computers cant I? Whats wrong with the 4th port?

I guess the most feasible solution proposed so far is to buy an 8 port hub. Any more suggestions?
0
 
MastaBlastaAuthor Commented:
I forgot to reply to the "it might be an IP conflict" comment. I dont think its that because first I tried DHCP, then thought it might be an IP conflict, so I assigned each computer a different local static IP. Did not work and the same problems remained.
0
 
MastaBlastaAuthor Commented:
"Turning off QOS in windowsxp network settings may help"

How do you think it will help? BTW, I had turned off netbios and file sharing from the start.
0
 
AutoSpongeCommented:
It's possible to have bad NICs or bad ports on the hub.  If you plug everything into a different port, do you get the same results?  If so, try swapping the NIC on the PC having the problem (maybe with another PC if you don't have a spare).  If you still get the same problem, it probably isn't the hardware.

The best thing to do is download Ethereal, load it on one of your machines, and start sniffing your network.  If it's a problem with late collisions, you'll see it right away.  It may take some study to learn what a sniffer tells you, but it's stuff worth learning.
0
 
MastaBlastaAuthor Commented:
"If you plug everything into a different port, do you get the same results?"

Yes. Will try Ethereal. Thanks
0
 
stevenlewisCommented:
the sporatic conenctions and the loss of connection smacks of a broadcast storm (bad NIC) on the new machine IMHO
0
 
AutoSpongeCommented:
I agree with stevenlewis, especially if you can reseat the switch/hub cable for the PC and get it to calm down.  
0
 
moorhouselondonCommented:
In answer to your question re using a Router, you would buy an ADSL Router, plug this into the Hub/Switch, and everything would work via this.  The USB Modem would be redundant.  Most decent Routers these days have a 4-port hub/switch built in, so you would not have a problem with the number of Ethernet connections you would have.  What I would suggest is that you leave the Uplink port alone on the original hub and use connections on the Router instead.  The Routers seem to be able to distinguish between straight-through and crossover connections, so you don't need to worry crossover cables or uplink ports.  FYI this is a solution that I have put into practice many times, and it works.  The tech support at the Router companies is really, really good, if you have any kind of config issue they are good at helping (and they are Toll Free numbers too).  For brands, I myself would go with SMC Barricade or Netgear.
0
 
MastaBlastaAuthor Commented:
I will definitely look into the router option.

I made another interesting observation yesterday. I disconnected the new comp, leaving only 3 comps on the network plus mine and it worked without a hitch. Then I plugged in the new comp in place of one of the old comp, thus still having 3 comps on the network plus mine. The new comp caused the same comp to act sporadically(as I had described earlier) but the others were unaffected. Whats more, the sporadic comp disconnected from the network DNS and reconfigured to a dynamic 169.xxx.xxx.xxx internal IP instead of the assigned 192.168.xxx.xxx IP. I checked for IP clashes but there were none. What is going on? Another thing. All the other comps by default establish a 10 mpbs connection to the network. The new comp establishes a 100 mbps connection. Can this be the cause of the problem? Cant be a bad NIC cause the internet on the new comp was working perfectly and cant be damaged ports on the hub. I disabled the QoS to see if it solved anything but to no avail. Whats going on? Thanks...
0
 
stevenlewisCommented:
try a pc card NIC on the laptop, should clear it right up
0
 
caball88Commented:
what speed is the hub rated at? if it supports 100mbps then all the computers should be connected at that speed(given that they have 10/100 nics). the internal ip is a feature of the network card which and might not be the problem. also you said you turned on full duplex on. sometimes various hubs might not support this and can only support half duplex. i would leave the setting to auto-detect. this way if the nics sense that the hardware is capable it will use it. this might or might not be the reason whe communication is sporadic.
0
 
wyliecoyoteukCommented:
The speed differential is a likely cause.
You probably have autonegotiation errors.
Some hubs and NICs don`t interact properly when establishing a speed .
I would suggest locking the suspect NIC card to 10Mbps half duplex, and see if that works OK.
If it does, try 100Mbps, half duplex, and then full duplex, etc stick with the best speed that works..
QOS can cause problems with bandwidth issues, which is why I suggested disabling it.


0
 
AutoSpongeCommented:
Based on your last observations, it's as I stated earlier--you have a bad NIC and need to change it.  If it's an on-baord NIC, make sure you disable it before installing the new one in the hardware profile.
0
 
wyliecoyoteukCommented:
Actually, it is more likely to be lack of compatability between hub and NIC.
This does not mean that either are faulty, just that they don`t co-operate.
The fact that it is a hub and not a switch means it is probably an older unit, and less compatable with newer NICs.
Mixing network speeds on older hubs can cause strange results.
The other consideration is wiring.
Are these purchased cables or home-made?
If home made, and wired incorrectly, they will operate at 10M but not 100M, this is because 10M uses wires 1+2, whereas 100M uses wires 1+2, and 3+6 (which should be wired in pairs)
The most common error is to connect pairs as 1+2,3+4,5+6,7+8, whereas they should be 1+2,3+6,4+5,7+8.
Gigabit cards use all 8 wires.

Another puzzling thing is the  uplink port. This should only be used for connecting hubs together, not for a PC connection (whether it is a server or not). The uplink port is wired in reverse to the standard ports for this reason, to simulate a crossover cable.

http://www.makeitsimple.com/how-to/dyi_crossover.htm

Perhaps the new PC, as it uses all 4 wires, is causing problems because you are using an uplink port to connect to your server.



0
 
MastaBlastaAuthor Commented:
Thank you for your help guys. wyliecoyoteuk's suggestion solved the problem. Cheers.
0

Featured Post

Transaction-level recovery for Oracle database

Veeam Explore for Oracle delivers low RTOs and RPOs with agentless transaction log backup and transaction-level recovery of Oracle databases. You can restore the database to a precise point in time, even to a specific transaction.

  • 6
  • 3
  • 3
  • +7
Tackle projects and never again get stuck behind a technical roadblock.
Join Now