All of lore.kernel.org
 help / color / mirror / Atom feed
From: Tony Wasson <wasson@azxws.com>
To: lartc@vger.kernel.org
Subject: Re: [LARTC] Accepting packets with frame dest.addr. ff:ff:ff:ff:ff:ff
Date: Thu, 22 Apr 2004 17:42:01 +0000	[thread overview]
Message-ID: <408803E9.4060902@azxws.com> (raw)
In-Reply-To: <4087740E.5050008@sunsite.mine.nu>

Martin Rusko wrote:
> Hi all,
> 
> do anybody know, whether is it possible to route packets incoming to 
> ethernet interface as broadcasts?
> 
> ~~~~~|WirelessDevice/WD|-----eth0-|LinuxRouter/RT|-eth1---(10.18.63.0/24)
> 
> tcpdump: listening on eth0
> 0:a:e6:ac:e8:7a ff:ff:ff:ff:ff:ff 98: 192.168.7.11 > 10.18.63.249: icmp: 
> echo request (DF)
> 0:a:e6:ac:e8:7a ff:ff:ff:ff:ff:ff 98: 192.168.7.11 > 10.18.63.249: icmp: 
> echo request (DF)
> 
> Please notice, that echo request packets are in ethernet frames, heading 
> to broadcast address (ff:ff:ff:ff:ff:ff).
> 
> Linux kernel seems to be, that refuse to route such packets (not 
> intented for the MAC address of eth0 interface). But that interface 
> received that packets, as seen in running tcpdump session. When that 
> frames has "correct" MAC addresses, I mean destination is not a 
> broadcast address, the same packet (source IP, destination IP) is routed 
> without any problem.
> 
> Do you have any explanation, for this? Or better, does any linux 
> networking guru know some magic, how to make linux kernel start routing 
> also broadcasted packets?
> 
> Any help will be much appreciated. Also, when more info, why I see such 
> packets is needed, I'm ready to serve.
> 
>          Best regards
> 
>               mARTin
> 

Hi Martin,

Routers are usually installed to seperate broadcast domains. They really 
don't *LIKE* to forward broadcasts. I am imagining that this is a really 
broken TCP/IP stack you are working with. Just for kicks, do you see 
ARPs right before these echo requests? If so, proxy ARP would help 
deliver your traffic.

Can you reveal more about what device is sending this interesting 
traffic? You may be able to set an ARP entry for 10.18.63.249 on the 
crazy network device as the linux box and "force" things to work.

Tony Wasson


_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/

  reply	other threads:[~2004-04-22 17:42 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-04-22  7:28 [LARTC] Accepting packets with frame dest.addr. ff:ff:ff:ff:ff:ff for routing Martin Rusko
2004-04-22 17:42 ` Tony Wasson [this message]
2004-04-23  8:50 ` [LARTC] Accepting packets with frame dest.addr. ff:ff:ff:ff:ff:ff Martin Rusko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=408803E9.4060902@azxws.com \
    --to=wasson@azxws.com \
    --cc=lartc@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.