LinuxQuestions.org
Review your favorite Linux distribution.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking
User Name
Password
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

Notices


Reply
  Search this Thread
Old 07-16-2004, 07:23 AM   #1
calluminsky
Member
 
Registered: Jul 2004
Location: Milton Keynes, UK
Distribution: Red Hat Fedora
Posts: 35

Rep: Reputation: 15
Unhappy Cannot connect to network via hub


Hi Everyone

I'm having strange problems with my Red Hat Fedora 1 machine. I've got a small network at home which has a Solaris machine, an AIX machine, and the Linux box all connected to an eight port switching hub which is also connected t a Wireless ethernet bridge, which in turn goes out to a Wireless ADSL modem. The Solaris and AIX machines can see each other no problem and can also ping the ADSL modem so I know there's nothing wrong with the bridge or the hub but the linux machine can't see anything! I've changed the cables, the port on the hub and plugged the bridge straight into the linux box and it works fine (once I change a setting on the bridge).

I'm thinking that I may have to change a kernel parameter but I don't know where to start. The NIC flashes on and off when connected to the hub but when plugged into the bridge, it's on all the time.

I've tried using the bridge as the default GW, the ADSL modem, the NIC itself but all to no avail.

Can someone please help!!!

Thanks!

Calluminsky
 
Old 07-16-2004, 10:18 AM   #2
NetAX
Member
 
Registered: Mar 2004
Location: Boston, MA
Distribution: SuSE Linux Open/Enterprise, Red Hat, Ubuntu
Posts: 147

Rep: Reputation: 17
What is the rated speed of the NIC for the linux box? (ex:10/100Mbps)

What is the rated speed of your NIC's on your AIX and Solaris machines?

Sounds like you have a hardware compatability issue.
 
Old 07-16-2004, 10:19 AM   #3
ppuru
Senior Member
 
Registered: Mar 2003
Location: Beautiful BC
Distribution: RedHat & clones, Slackware, SuSE, OpenBSD
Posts: 1,791

Rep: Reputation: 50
can u check

1. dmesg |grep eth
2. /sbin/lspci |grep eth
3. /sbin/ifconfig

1&2 will give info whether linux detects the NIC at boot

You can also check the entries in /etc/sysconfig/hwconf to check whether your NIC is detected.

lsmod will help you ascertain that the proper driver modules are loaded.

These are only pointers that may help you find the problem.
 
Old 07-16-2004, 12:44 PM   #4
calluminsky
Member
 
Registered: Jul 2004
Location: Milton Keynes, UK
Distribution: Red Hat Fedora
Posts: 35

Original Poster
Rep: Reputation: 15
Hi

Thanks for the reply but the NIC on all of the machines are standard 10/100 as is the switching hub.

The NIC in the linux machine is a Linksys one, using the tulip driver and configured no problem. The wireless bridge is also linksys.

To be honest, I don't think it's hardware since everything works fine when I plug the wireless bridge straight into the Linux NIC. Problems on happen when I plug the same card into the switching hub.

The NIC is certainly detected because I can see it through ifconfig, netstat show it's routing info, I can ping it from itself and so on. dmesg shows its there too.

Is there something I have to enable/disable to get the linux box to talk to a switching hub? I've looked at iptables and that's completely off so nothing there. All the machines are in the same network and have the same netmask (it's a class C so 255.255.255.0 right?)...

Cheers!

calluminsky
 
Old 07-17-2004, 12:21 AM   #5
temdesign
Member
 
Registered: Jul 2004
Location: New Orleans
Posts: 35

Rep: Reputation: 15
A question

Why do you have a Network Bridge? Your computers should be plugged into a Cable/DSL Router into the LAN ports and then your Cable/DSL Modem plugged into your WAN port on the router. That will let all your machines work on the net.
 
Old 07-19-2004, 11:16 AM   #6
calluminsky
Member
 
Registered: Jul 2004
Location: Milton Keynes, UK
Distribution: Red Hat Fedora
Posts: 35

Original Poster
Rep: Reputation: 15
Sorry, I don't understand...

My network is done thus:

1 x adsl modem connected via ethernet into an adsl wireless router. This is in one room.

1 x adsl wireless ethernet bridge connected into a small 8 port switching hub.

1 x Solaris machine connected into the hub

1 x AIX machine connected into the hub

1 x Fedora machine connected into the hub

Now, the whole point of this is so that the machines in my office can see the wireless network which starts in a completely different part of my apartment. To illuminate the last poster as to why I've done it this way:

I don't want any machines in my living area - only in my office. My girlfriend can just about stomach the router and modem but that's it!!!

As I think I've mentioned before, the Solaris and AIX machines can all see both the wireless bridge and the adsl router and get onto the web no problem. The Linux machine can't. So, my questions are:

What is different about the way linux routes data that Solaris and AIX? Why can I not get through the hub from the Linux machine whilst I can do this no problem with Unix? Is there something I need to do to allow the Linux machine to see the switching hub or forward traffic outwards?

Many thanks!

Hope that explains why I've done my network this way - the power of women should not be underestimated!!!

Calluminsky
 
Old 07-19-2004, 07:25 PM   #7
temdesign
Member
 
Registered: Jul 2004
Location: New Orleans
Posts: 35

Rep: Reputation: 15
The point is

You do not need a bridge if you have a 8 port hub and a ADSL modem. Connect the ADSL modem into the router on the wan port. Take a straight cable out of the LAN port on the Wireless router and into the 8 port Hub. Then connect your machines in to the hub. You do not need the bridge. Also, do you not have another phone jack in the room where the computers are? If so, plug your ADSL modem into that jack and then everything will be in the same room.
 
Old 07-20-2004, 03:25 AM   #8
calluminsky
Member
 
Registered: Jul 2004
Location: Milton Keynes, UK
Distribution: Red Hat Fedora
Posts: 35

Original Poster
Rep: Reputation: 15
This is so not what I want to do!

The whole point of my wireless bridge and wireless adsl router is that I want WIRELESS!!! I don't want and I don't need cables and machines strewn all over my apartment... *sigh*

No, I don't have another phone jack in the room where the machines are. I don't want one. I don't need one.

Honestly, thanks for the reply but this isn't helping.

All I need to do is find out whether I need to change something in Linux to allow it to see a hub and the bridge. The gateway has been set but it's not working. The gateway is in the same network, the other machines can all see it, the only problem, as I've reiterated a couple of times is that the Linux machine can't...

Again, the specs of the machine and network:

1 x Fedora machine with Linksys 10/100 card connected to...
1 x 8 port switching hub connected to...
1 x AIX machine
1 x Solaris machine
1 x wireless ethernet bridge which talks to...
1 x wireless router which is directly connected to...
1 x adsl modem...

Seriously, this isn't a question I haven't thought about and the only reason I'm posting here is to find out what I have to change to get the Linux machine to see the gateway... there must BE something I'm missing since the other boxes work fine...

Or would I just can linux and go with x86 Solaris?

Is it NAT? IP forwarding? What can it be???

Calluminsky
 
Old 07-20-2004, 08:13 AM   #9
temdesign
Member
 
Registered: Jul 2004
Location: New Orleans
Posts: 35

Rep: Reputation: 15
Sorry....You're in the UK

You do not need a bridge if you have a 8 port hub and a ADSL modem. Connect the ADSL modem into the router on the wan port. Take a straight cable out of the LAN port on the Wireless router and into the 8 port Hub. Then connect your machines in to the hub. You do not need the bridge. Also, do you not have another phone jack in the room where the computers are? If so, plug your ADSL modem into that jack and then everything will be in the same room.

HA....You're in the UK!

Last edited by temdesign; 07-22-2004 at 12:58 AM.
 
Old 07-20-2004, 09:28 AM   #10
calluminsky
Member
 
Registered: Jul 2004
Location: Milton Keynes, UK
Distribution: Red Hat Fedora
Posts: 35

Original Poster
Rep: Reputation: 15
OK, firstly I don't believe that i have been anything but courteous to you in the past. I have simply asked for advise as to what I may have missed in terms of getting my Linux machine to behave and believe it or not, I don't feel that I "have" to follow your advise.

No, I am not an expert on Networking. I am however an experienced Unix professional and I have, believe it or not, managed to get my HOME network working with Solaris and AIX. I am NOT a networking guru, nor am I, or have ever claimed to be, a LINUX guru.

Hey! Guess what? THAT'S WHY I POSTED A QUESTION!

You seem to be under the misconception that forums are for "experts" like yourself to tell people how THEY MUST do things. They're not. They're for discussion. I asked the FORUM (and not you personally - but I initially appreciated the time and trouble you took to respond) as to what I might need to change on the linux side to get it talking to my wireless bridge.

Now, to focus on your last post:

Please enlighten me as to how one gets a wireless router in one room to talk to a standard, inexpensive 8 port WIRED switch and machines configured on it without a WIRELESS bridge? Pray tell me if there is a magical device that we in the UK have not had the pleasure of seeing but is currently taking the US by storm?

As I think I mentioned, I would like to configure my network this way because I do not want any machines being linked to my ADSL connection and wireless router directly. Why? Cables around the apartment = angry girlfriend. It's my decision to use a wireless network in this way so please respect that. At no point have I professed to being anything but a networking amateur - I am a UNIX Consultant - but hey, I do know how to configure default gateways, understand network classes and subnets, VPN's and can even write a mean iptables rule if needs be... oh, and I also know what the localhost entry is and its significance!!!

Back to my original point, do you, in your expert networking/linux guru opinion, know what I need to change to have my linux machine talk to the bridge via the hub? If not, then please just say so. Don't take a "this will work if you change your network" approach. I know this already as I, despite my "inefficient" approach to networking, have got my Linux machine talking to the wireless BRIDGE in the past by connecting it directly, via cable, to my NIC. I remember mentioning this in my earlier posts.

One other thing, the whole point of the bridge is so that the OTHER MACHINES in my network can share the connection to the internet. The bridge, via the hub, allows me to do this with standard on board ethernet ports on the Sun and IBM machines. This lets me circumvent any potential problems with wireless PCI cards on AIX, Solaris and indeed on Linux.

Now, I hope this has addressed your last post in a slightly more polite manner than yours. I really do appreciate you replying and thank you for your effort but please do not slander my own skills simply because I do not wish to configure a network in the manner that you have suggested. My approach may be "inefficient" in your opinion and you are entitled to that opinion, but I have taken this approach for reasons I feel I have explained (even though I don't have to - it's surely up to me to configure it how I want?) already.

If anyone has any clue as to how I get this working on Linux, that DOESN'T involve cabling around my apartment, then please respond!

Calluminsky

Calluminsky
 
Old 07-20-2004, 11:19 PM   #11
temdesign
Member
 
Registered: Jul 2004
Location: New Orleans
Posts: 35

Rep: Reputation: 15
Re-Read

Nothing I posted involved running cabling in your apt. It was to simply leave everything as is except take out the bridge.....However, I have wasted much time already....I am going to take my CCNA and go crawl back into my cave.


Good night.
 
Old 07-21-2004, 01:14 AM   #12
chort
Senior Member
 
Registered: Jul 2003
Location: Silicon Valley, USA
Distribution: OpenBSD 4.6, OS X 10.6.2, CentOS 4 & 5
Posts: 3,660

Rep: Reputation: 69
temdesign: First, don't do that again. Let's keep it at one warning.

Second, if he takes out the bridge, the only way to connect the hub/switch to the ADSL router is via cat5/6. As he so carefully explained, the bridge exists to provide an uplink to the hub/switch back to the wireless router, which connects to the ADSL modem (router, technically speaking). What could be more simple? The only way to connect if you removed the bridge would be to put a WiFi card in each of his three machines, but clearly he stated that they have wired NICs, not wireless...

With network advice like that, it will be a miracle if you pass your CCNA (sorry, but you brought that one on yourself).

Now to Calluminsky, about your actual question... First off, what is the configuration of the other two boxen (Solaris and AIX)? What's the output of ifconfig -a from each of those boxen and also netstat -rna? Now post the output from the Linux box of ifconfig -a and netstat -rna. I want to compare them. Also, if you have the IP and netmask of the wireless router please post that as well. I assume the bridge does not have an IP.

Last, were you trying to contact things on the 'net via hostname/FQDN, or IP? If you were only trying hostnames or fully-qualified domain names, try using IPs instead. It might be a DNS issue and not a routing/IP issue.
 
Old 07-21-2004, 01:42 AM   #13
ppuru
Senior Member
 
Registered: Mar 2003
Location: Beautiful BC
Distribution: RedHat & clones, Slackware, SuSE, OpenBSD
Posts: 1,791

Rep: Reputation: 50
An additional point ... if you have allowed the installation to configure a firewall, that could be restricting traffic.

you may try stopping iptables and check whether that helps.

#service iptables stop
 
Old 07-21-2004, 05:22 AM   #14
calluminsky
Member
 
Registered: Jul 2004
Location: Milton Keynes, UK
Distribution: Red Hat Fedora
Posts: 35

Original Poster
Rep: Reputation: 15
Gentlemen,

Thanks very much for the replies.

iptables is actually off already so that can be ruled out. However, one thing I have been mulling over is the ip forwarding option. Could this be stopping the data from getting to where it needs to? It's the only thing that I can think of that may possibly be different in a default linux install to a Solaris or AIX installation. I can't check this until tonight but would it be, in your opinion, a possibility or am I barking up the wrong tree?

Essentially, the machines are at home so I can't post the ifconfig outputs until this evening but off the top of my head, the AIX and Solaris machines have IP addresses of:

Address Netmask Machine
192.*.*.15 255.255.255.0 Solaris
192.*.*.20 255.255.255.0 AIX
192.*.*.1 255.255.255.0 Wireless router
192.*.*.2 255.255.255.0 Wireless bridge
192.*.*.10 255.255.255.0 Linux

I've not actually changed the routing tables for the Solaris and AIX machines so they're simply set to standard configs. The broadcast address of each machine is 192.*.*.255.

I shall post more detailed information tonight when I get home.

Once again, many thanks for your time and suggestions!

Calluminsky
 
Old 07-21-2004, 05:37 AM   #15
ppuru
Senior Member
 
Registered: Mar 2003
Location: Beautiful BC
Distribution: RedHat & clones, Slackware, SuSE, OpenBSD
Posts: 1,791

Rep: Reputation: 50
Quote:
However, one thing I have been mulling over is the ip forwarding option. Could this be stopping the data from getting to where it needs to?
ip_forward would hold relevance only in a situation where your linux box is acting like a gateway to other systems. In your case, your linux box is just another client like Solaris and AIX.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Scripts for Open Direct Connect Hub Miyamoto Linux - Software 1 01-02-2005 07:57 AM
Can one linux PC have 2 NIC connect to one Hub ? nhgiang Linux - Networking 5 01-02-2005 07:31 AM
Netgear (WGR614) as hub can't connect via Browser stardotstar Linux - Networking 1 12-15-2004 12:03 AM
How to make work a Direct Connect client and a DC Hub on the same box? 4mix Linux - Software 0 10-30-2004 04:32 AM
connect switch to hub? ody1 Linux - Networking 3 04-12-2004 08:42 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Networking

All times are GMT -5. The time now is 04:39 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration