LinuxQuestions.org
Go Job Hunting at the LQ Job Marketplace
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 10-28-2004, 04:57 AM   #1
rickthemick
Member
 
Registered: Aug 2003
Location: Sweden
Distribution: Debian
Posts: 52

Rep: Reputation: 15
Broadcast in ad hoc networks


Hi all!
Problem: Broadcast packets are not delivered up to application from a different networkaddress.

Network setup: 2 hosts, 802.11 in ad hoc mode

[h1:10.0.3.2/24]--->packets(dst:255.255.255.255)--->[h2:10.0.1.1/24]

The problem is that h2 does not deliver any packets addressed to 255.255.255.255 (link local broadcast are not delivered either) from h1. My initilial thought was that this would work fine since both hosts are in ad hoc mode and should not care about the source IP adress but it seems that h2 does not deliver any pakets from h1 becuase of the "incorrect" source address (it does not belong to h2's network). I can se the packets comming in on h2 using Ethereal but they seems to be dropped.

Is it a incorrect understanding of ad hoc mode that it delivers any packet without considering the source address? (it seems so) If this is so, why does a ad hoc network consider the source address? (Seems odd to me) Is there any solution to this?

This set up works fine:
[h1:10.0.1.2/24]--->packets(255.255.255.255)--->[h2:10.0.1.1/24]
but I am limited to use the first setup with differnet network addresses.

Best Regards
Rickard
 
Old 10-28-2004, 06:20 PM   #2
slide-rule
Member
 
Registered: Jan 2004
Location: New England area, US
Distribution: Mandrake 9.2
Posts: 39

Rep: Reputation: 15
I'm probably totally missing the point of your problem, but if you need 10.0.2.* and 10.0.3.* to get traffic between them, oughtn't their netmasks be /16 and not /24 ? That they both work as 10.0.1.*/24 seems to be consistent to this. (Past this low-level observation, I'm unfamiliar with the vagaries of "ad-hoc", etc.)
 
Old 10-29-2004, 09:49 AM   #3
rickthemick
Member
 
Registered: Aug 2003
Location: Sweden
Distribution: Debian
Posts: 52

Original Poster
Rep: Reputation: 15
Im probably totally missing the point of your problem, but if you need 10.0.2.* and 10.0.3.* to get traffic between them, oughtn't their netmasks be /16 and not /24 ?

Yes, thats true, it would work, but its not an option for me.

That they both work as 10.0.1.*/24 seems to be consistent to this. (Past this low-level bservation, I'm unfamiliar with the vagaries of "ad-hoc", etc.)

Also true. But it actually has nothing to do with Ad hoc networking I believe, the same would hold for standard ethernet cards connected through a hub.

Made a post where I claim that DHCP solves this problem, and made a question how. My thought is that the DHCP client set the source address to 0.0.0.0 which will make the packet to not be dropped at the IP-stack of the receiver.

My post about DHCP can be found here:
(changed topic so it will be seen by people who know DHCP well)
http://www.linuxquestions.org/questi...hreadid=248727
 
  


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
ad hoc in linux rajen_iiit Linux - Networking 1 08-07-2005 03:42 PM
How to ad-hoc in linux? enigma_0Z Linux - Wireless Networking 3 06-01-2005 07:54 PM
ad-hoc in Linux. How? dimgr Linux - Wireless Networking 1 04-13-2005 01:23 PM
More than two adapters using ad-hoc andrewjjones Linux - Wireless Networking 5 10-20-2004 05:29 PM
question on ad-hoc n/ws h/w Linux - Networking 2 11-16-2003 02:41 PM


All times are GMT -5. The time now is 05:04 AM.

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
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration