Linux Ethernet Bridge

ratheesh k | 1 Jul 2010 19:05

Picon

Re: Bridge blocking network traffic

On Thu, Jul 1, 2010 at 12:45 AM, Grant Taylor <gtaylor <at> riverviewtech.net> wrote:
> On 06/30/10 02:50, ratheesh k wrote:
>>
>> Why is it so ?
>
> Independent of your scenario, I'd say that binding the IP to the interface
> will make it more resilient to the individual interfaces going down.  At
> least in such as all the interfaces would have to go down before the IP
> would go down.
>
>> I have a linux   machine with interfaces eth0 (192.168.1.100 ) and eth1 (
>> 192.168.2.100 )  .   . I can connect  both eth0 an eth1  to a hardware  HUB
>> . How could i do this in linux machine itself using brctl ?
>
> What netmask are your two IPs using, a /24?  If they are, then you are
> actually using two different subnets, and possibly doing something like a
> bridging router.
>
> Either way, you could bind both IPs to the bridge interface (classic IP
> alias or "ip add").
>
> With in the Xen context it may be because different things manage various
> parts of the Xen network differently and having the IP bound in the wrong
> place might cause a problem if the Xen hypervisor takes something down.
>
> There is also the fact that if a cable gets unplugged from an interface
> (that is a member of a bridge with at least one other member interface) said
> interface will go down but the bridge will stay up.  In doing so, the IP
> will go down b/c the interface that it was bound to would go down.
>  Conversely if the IP was bound to the bridge interface, the IP would stay

(Continue reading)

ratheesh k | 1 Jul 2010 20:14

Picon

Re: Bridge blocking network traffic

>On Thu, Jul 1, 2010 11:27 PM, Pascal Hambourg <pascal.mail <at> plouf.fr.eu.org> wrote:
> I strongly doubt it. This rule forces routing of all packets instead of
> bridging, so IIUC it effectively totally disables bridging and you are
> back to two independent interfaces.

 I am sorry that i made a ambigous statement .
 what i meant is : We could add rules to BROUTING to selectively
bridge and route packets .Previously i was not able to ping eth0 or
eth1 from some other machine (in same subnet ) if i attach both to br0
. This got solved when we made default policy as DROP .

On Thu, Jul 1, 2010 at 11:27 PM, Pascal Hambourg
<pascal.mail <at> plouf.fr.eu.org> wrote:
> ratheesh k a écrit :
>>
>> brctl addbr br0
>> brctl  addif eth0
>> brctl  addif eth1
>> ifconfig br0  0.0.0.0 up
>>
>> The problem was "default brouter policy is accept " . So packets are
>> coming to layer2  only .
>
> Indeed, by default (i.e. no brouting) packets received on a bridge port
> are intercepted by the bridge. This is the intended behaviour of a
> bridge, isn't it ? Thus a bridge port is not supposed to be assigned an
> IP address (or be used by any protocol), because the IP stack (or any
> other upper protocol layer) won't receive any packet directly from it
> but from the bridge interface (which should have the IP address).
>

(Continue reading)

Jonathan Thibault | 1 Jul 2010 20:24

Re: Enquiry on Linux bridge

 As far as I can tell, the setup you describe should work as expected. I am not sure what causes the problem you
describe. The first thing I would check is if the bridge interfaces (br0) have the same MAC address, they
should not.

Jonathan

On 30/06/10 02:37 AM, Ng Ming Ann wrote:
>
> Dear all,
>
> I’m currently working on a Ethernet bridge for a system. I have a machine(not PC, but an embedded system)
which has two Ethernet ports, I wanted to configure it into a Ethernet bridge which connect other PC.
>
> I have tested on configuring it into a bridge where the two PC able to ping each other and send files. I’m
wondering that whether I can involve the embedded Linux system in the network, where the two PC able to
detect the Linux OS( embedded system) and able to send files and communicate with it as the figure below:
>
> Rounded Rectangle: Embedded System ( Bridge)
>
>
> 	
> 	
> 	
> 	
> 	
> 	
> 	
>
> 	
>

(Continue reading)

Rodolfo Giometti | 2 Jul 2010 15:56

rstpd & 2.4

Hello,

project rstpd at
http://git.kernel.org/?p=linux/kernel/git/shemminger/rstp.git can work
if default kernel stp is disabled by calling userspace program
/sbin/bridge-stp and checking the return code.

On 2.4.27 such mechanism is not implemented so should I backport some
kernel code or I can just disable the STP by using the
BRCTL_SET_BRIDGE_STP_STATE ioctl command? There are any drawbacks in
doing so?

Thanks in advance,

Rodolfo

--

-- 

GNU/Linux Solutions                  e-mail: giometti <at> enneenne.com
Linux Device Driver                          giometti <at> linux.it
Embedded Systems                     phone:  +39 349 2432127
UNIX programming                     skype:  rodolfo.giometti
Freelance ICT Italia - Consulente ICT Italia - www.consulenti-ict.it

Stephen Hemminger | 2 Jul 2010 18:21

Re: rstpd & 2.4

On Fri, 2 Jul 2010 15:56:41 +0200
Rodolfo Giometti <giometti <at> enneenne.com> wrote:

> Hello,
> 
> project rstpd at
> http://git.kernel.org/?p=linux/kernel/git/shemminger/rstp.git can work
> if default kernel stp is disabled by calling userspace program
> /sbin/bridge-stp and checking the return code.
> 
> On 2.4.27 such mechanism is not implemented so should I backport some
> kernel code or I can just disable the STP by using the
> BRCTL_SET_BRIDGE_STP_STATE ioctl command? There are any drawbacks in
> doing so?

The 2.4 kernel is missing all the hooks to provide user level STP.
The startup is not the big issue, the real problem is that the
kernel doesn't have hooks to control port state from user space,
and the spanning tree packets may not be visible to user space
application either.

Sigh, 2.4 is at least 5 years old by now.

Rodolfo Giometti | 2 Jul 2010 21:22

Re: rstpd & 2.4

On Fri, Jul 02, 2010 at 09:21:48AM -0700, Stephen Hemminger wrote:
> On Fri, 2 Jul 2010 15:56:41 +0200
> Rodolfo Giometti <giometti <at> enneenne.com> wrote:
> 
> > Hello,
> > 
> > project rstpd at
> > http://git.kernel.org/?p=linux/kernel/git/shemminger/rstp.git can work
> > if default kernel stp is disabled by calling userspace program
> > /sbin/bridge-stp and checking the return code.
> > 
> > On 2.4.27 such mechanism is not implemented so should I backport some
> > kernel code or I can just disable the STP by using the
> > BRCTL_SET_BRIDGE_STP_STATE ioctl command? There are any drawbacks in
> > doing so?
> 
> 
> The 2.4 kernel is missing all the hooks to provide user level STP.
> The startup is not the big issue, the real problem is that the
> kernel doesn't have hooks to control port state from user space,

These could be added...

> and the spanning tree packets may not be visible to user space
> application either.

Neither using a packet sniffer?

> Sigh, 2.4 is at least 5 years old by now.

(Continue reading)

Pascal Hambourg | 1 Jul 2010 19:57

Re: Bridge blocking network traffic

ratheesh k a écrit :
> 
> brctl addbr br0
> brctl  addif eth0
> brctl  addif eth1
> ifconfig br0  0.0.0.0 up
> 
> The problem was "default brouter policy is accept " . So packets are
> coming to layer2  only .

Indeed, by default (i.e. no brouting) packets received on a bridge port
are intercepted by the bridge. This is the intended behaviour of a
bridge, isn't it ? Thus a bridge port is not supposed to be assigned an
IP address (or be used by any protocol), because the IP stack (or any
other upper protocol layer) won't receive any packet directly from it
but from the bridge interface (which should have the IP address).

>I applied the below command and every thing
> seemed to work exactly like connecting eth0 and eth1 to hardware hub .
> 
> ebtables -t broute  -P BROUTING -j DROP

I strongly doubt it. This rule forces routing of all packets instead of
bridging, so IIUC it effectively totally disables bridging and you are
back to two independent interfaces.

Stephen Hemminger | 15 Jul 2010 21:21

Re: [PATCH 7/8] net: bridge: fix sign bug

On Thu, 15 Jul 2010 22:47:33 +0400
Kulikov Vasiliy <segooon <at> gmail.com> wrote:

> ipv6_skip_exthdr() can return error code that is below zero.
> 'offset' is unsigned, so it makes no sense.
> ipv6_skip_exthdr() returns 'int' so we can painlessly change type of
> offset to int.
> 
> Signed-off-by: Kulikov Vasiliy <segooon <at> gmail.com>
> ---
>  net/bridge/br_multicast.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
> index 27ae946..85afcda 100644
> --- a/net/bridge/br_multicast.c
> +++ b/net/bridge/br_multicast.c
>  <at>  <at>  -1435,7 +1435,7  <at>  <at>  static int br_multicast_ipv6_rcv(struct net_bridge *br,
>  	struct icmp6hdr *icmp6h;
>  	u8 nexthdr;
>  	unsigned len;
> -	unsigned offset;
> +	int offset;
>  	int err;
>  
>  	if (!pskb_may_pull(skb, sizeof(*ip6h)))

Acked-by: Stephen Hemminger <shemminger <at> vyatta.com>

--

--

(Continue reading)

David Miller | 16 Jul 2010 05:28

Re: [PATCH 7/8] net: bridge: fix sign bug

From: Stephen Hemminger <shemminger <at> linux-foundation.org>
Date: Thu, 15 Jul 2010 12:21:44 -0700

> On Thu, 15 Jul 2010 22:47:33 +0400
> Kulikov Vasiliy <segooon <at> gmail.com> wrote:
> 
>> ipv6_skip_exthdr() can return error code that is below zero.
>> 'offset' is unsigned, so it makes no sense.
>> ipv6_skip_exthdr() returns 'int' so we can painlessly change type of
>> offset to int.
>> 
>> Signed-off-by: Kulikov Vasiliy <segooon <at> gmail.com>
...
> Acked-by: Stephen Hemminger <shemminger <at> vyatta.com>

Applied.

Kulikov Vasiliy | 15 Jul 2010 20:47

Picon

[PATCH 7/8] net: bridge: fix sign bug

ipv6_skip_exthdr() can return error code that is below zero.
'offset' is unsigned, so it makes no sense.
ipv6_skip_exthdr() returns 'int' so we can painlessly change type of
offset to int.

Signed-off-by: Kulikov Vasiliy <segooon <at> gmail.com>
---
 net/bridge/br_multicast.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 27ae946..85afcda 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
 <at>  <at>  -1435,7 +1435,7  <at>  <at>  static int br_multicast_ipv6_rcv(struct net_bridge *br,
 	struct icmp6hdr *icmp6h;
 	u8 nexthdr;
 	unsigned len;
-	unsigned offset;
+	int offset;
 	int err;

 	if (!pskb_may_pull(skb, sizeof(*ip6h)))
--

-- 
1.7.0.4

Group

gmane.linux.network.bridge.

Search Archive

Page

1 | 2 | 3

Articles in period: 20

July 2010

Language

Change language

Options

Current view: Threads only / Showing only 20 lines / Not hiding cited text.
Change to All messages, whole messages, or hide cited text.

Post a message
NNTP Newsgroup
Classic Gmane web interface
XML

XML

RSS Feed
List Information

About Gmane

Recent entries

[PATCHv4 net-next 0/2] Add two new flags to bridge. (30 Apr 2013)
[PATCHv2 net-next 0/2] Add two new flags to bridge. (29 Apr 2013)
[PATCH net-next 0/2] Add some new flags to bridges. (29 Apr 2013)
[PATCH v2 net-next 0/6] Allow bridge to function in non-promisc mode (19 Apr 2013)
Configuration-messages from root switch hello-timer not forwarded (19 Apr 2013)
[PATCH] bridge: Add missing include for in6_addr (18 Apr 2013)
[PATCH] Notify userspace about bridge learning MAC on new port (15 Apr 2013)
bridging and VLANs (15 Apr 2013)
[PATCH net] bridge: make user modified path cost sticky (14 Apr 2013)
[PATCH 0/3] bridge: implement restricted forwarding policy (8 Apr 2013)
network namespace + bridge visibility (28 Mar 2013)
[PATCH net-next] bridge: remove unused variable ifm (28 Mar 2013)
[PATCH] bridge: fix crash when set mac address of br interface (23 Mar 2013)
[PATCH net-next] bridge: avoid br_ifinfo_notify when nothing changed (23 Mar 2013)
[PATCH 2/2] bridge: Use IPv6 link-local address for multicast listener (20 Mar 2013)
[PATCH v2] net: add ETH_P_802_3_MIN (28 Mar 2013)
[PATCH] bridge: netfilter: use PTR_RET instead of IS_ERR + PTR_ERR (12 Mar 2013)
[PATCH -next] bridge: using for_each_set_bit to simplify the code (11 Mar 2013)
[PATCH -next] bridge: using for_each_set_bit_from to simplify the code (11 Mar 2013)
[PATCH] bridge-utils: Fix compile against linux-3.8.x (6 Mar 2013)
Problem with multicast traffic when using network bridging (23 Feb 2013)

Archives

8	May 2013
60	April 2013
80	March 2013
66	February 2013
140	January 2013
71	December 2012
20	November 2012
12	October 2012
12	September 2012
55	August 2012
10	July 2012
15	June 2012
18	May 2012
3	April 2012
40	March 2012
21	February 2012
17	January 2012
17	December 2011
39	November 2011
2	October 2011
18	September 2011
27	August 2011
6	July 2011
16	June 2011
51	May 2011
35	April 2011
100	March 2011
43	February 2011
23	January 2011
24	December 2010
21	November 2010
53	October 2010
10	September 2010
41	August 2010
20	July 2010
43	June 2010
47	May 2010
57	April 2010
102	March 2010
31	February 2010
82	January 2010
46	December 2009
103	November 2009
8	October 2009
11	September 2009
92	August 2009
27	July 2009
81	June 2009
143	May 2009
96	April 2009
82	March 2009
23	February 2009
44	January 2009
12	December 2008
39	November 2008
30	October 2008
31	September 2008
28	August 2008
43	July 2008
55	June 2008
51	May 2008
54	April 2008
67	March 2008
16	February 2008
33	January 2008
13	December 2007
52	November 2007
29	October 2007
35	September 2007
36	August 2007
20	July 2007
17	June 2007
30	May 2007
72	April 2007
73	March 2007
44	February 2007
38	January 2007
50	December 2006
38	November 2006
38	October 2006
32	September 2006
37	August 2006
37	July 2006
29	June 2006
40	May 2006
34	April 2006
19	March 2006
19	February 2006
21	January 2006
40	December 2005
38	November 2005
27	October 2005
30	September 2005
38	August 2005
30	July 2005
38	June 2005
51	May 2005
24	April 2005
47	March 2005
20	February 2005
97	January 2005
37	December 2004
15	November 2004
6	October 2004
52	September 2004
99	August 2004
71	July 2004
70	June 2004
71	May 2004
56	April 2004
54	March 2004
39	February 2004
37	January 2004
9	December 2003
11	November 2003
40	October 2003
48	September 2003
44	August 2003
64	July 2003
87	June 2003
78	May 2003
83	April 2003
75	March 2003
148	February 2003
68	January 2003
65	December 2002
84	November 2002
121	October 2002
82	September 2002
6	July 2002
89	June 2002
113	May 2002
103	April 2002
1	September 2001

Design

Zawodny | Right Menu | Left Menu

Your Own Design

Paste the URL of your CSS below. Download CSS template