Wirless bridge?

Posted on 2004-04-17
Medium Priority
Last Modified: 2012-06-21
I need help setting up a wireless bridge on my Fedora Core 1 server. This Linux server provides file, print, ADSL etc services to a home network of Windows XP PCs.  I want to extend this network wirelessly to my Dell Centrino portable.

I reconfigured the kernel with wireless and bridge support and installed a generic 8180 wireless card using ndiswrapper.  I have configured it so:
iwconfig wlan0 channel 1
iwconfig wlan0 mode Ad-Hoc
iwconfig wlan0 essid any
ifconfig wlan0 broadcast netmask  I have copied the output from ifconfig and  iwconfig below.  The portable now detects its presence.

I think I want a simple bridge which just sends/receives packets from eth0 to wlan0, no fancy tricks.  But if I create a bridge like this:
Brctl addbr br0
Brctl addif br0 etho
Brctl addif br0 wla0

then it doesn’t work and the network stops.  What do I need to do?


eth0      Link encap:Ethernet  HWaddr 00:04:E2:0E:02:8A  
          inet addr:  Bcast:  Mask:
          RX packets:3388 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3009 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:480517 (469.2 Kb)  TX bytes:956396 (933.9 Kb)
          Interrupt:12 Base address:0xd000

eth1      Link encap:Ethernet  HWaddr 00:40:F4:5F:04:1A  
          RX packets:547 errors:0 dropped:0 overruns:0 frame:0
          TX packets:577 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:226238 (220.9 Kb)  TX bytes:67785 (66.1 Kb)
          Interrupt:3 Base address:0x5000

lo        Link encap:Local Loopback  
          inet addr:  Mask:
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

ppp0      Link encap:Point-to-Point Protocol  
          inet addr:  P-t-P:  Mask:
          RX packets:483 errors:0 dropped:0 overruns:0 frame:0
          TX packets:514 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:211688 (206.7 Kb)  TX bytes:54418 (53.1 Kb)

wlan0     Link encap:Ethernet  HWaddr 00:40:F4:5E:62:D2  
          inet addr:  Bcast:  Mask:
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)
          Interrupt:5 Memory:ea000000-ea0000ff


wlan0     IEEE 802.11b  ESSID:"any"  Nickname:"wire"
          Mode:Ad-Hoc  Frequency:2.412GHz  Cell: 02:E0:8E:7D:9C:80  
          Bit Rate=11Mb/s   Tx-Power:20 dBm   Sensitivity=0/3  
          RTS thr=2432 B   Fragment thr=2432 B  
          Encryption key:off
          Power Management:off
          Link Quality:100/100  Signal level:-95 dBm  Noise level:-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

Question by:ajcocker
  • 2

Expert Comment

ID: 10872845
so basically you are trying to share internet access from the linux machine to the centrino???

if so check out this info


Author Comment

ID: 10875855
No not really. I am already sharing internet access.  The linux server is the internet gateway for my network. I use iptables and masquerading.  I just want the portable to be linked to the network in the same way as if it was connected to an access point.

It should be possible.  There is an article at www-106.ibm.com/developerworks/linux/library/l-wap.html which describes something very similar which builds wireless access point running linux on an embedded system.

Accepted Solution

willy134 earned 1800 total points
ID: 10879471
from what I understand about bridges (which may be limited) a bridge will make it look like your centrino is connected directly to the network as if it were the linux box.  However, when you do this the linux box is no longer connected because of the bridge ( that linux box ip now is the ip of the laptop and all packets route to the laptop).

When you set up the connection sharing with NAT it will route the wlan0 packets it recieves to the eth0 without disabling the rest of your eth0 stuff.  However this limits the wireless notebook from being a server (because nat is not nice with port mapping)

Featured Post

Train for your Pen Testing Engineer Certification

Enroll today in this bundle of courses to gain experience in the logistics of pen testing, Linux fundamentals, vulnerability assessments, detecting live systems, and more! This series, valued at $3,000, is free for Premium members, Team Accounts, and Qualified Experts.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

I have seen several blogs and forum entries elsewhere state that because NTFS volumes do not support linux ownership or permissions, they cannot be used for anonymous ftp upload through the vsftpd program.   IT can be done and here's how to get i…
Note: for this to work properly you need to use a Cross-Over network cable. 1. Connect both servers S1 and S2 on the second network slots respectively. Note that you can use the 1st slots but usually these would be occupied by the Service Provide…
If you're a developer or IT admin, you’re probably tasked with managing multiple websites, servers, applications, and levels of security on a daily basis. While this can be extremely time consuming, it can also be frustrating when systems aren't wor…
Watch the video of Kernel Migrator for SharePoint, which demonstrate the process easily of migration from SharePoint to SharePoint, OneDrive for Business & Google Drive servers, Public Folder to SharePoint, File Server to SharePoint. The tool has va…

619 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question