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From: Stephen Hemminger <shemminger@vyatta.com>
To: Jan Engelhardt <jengelh@medozas.de>
Cc: Jonathan Tripathy <jonnyt@abpni.co.uk>, netfilter@vger.kernel.org
Subject: Re: Bridges
Date: Tue, 17 Aug 2010 16:34:05 -0700	[thread overview]
Message-ID: <20100817163405.0713cee9@nehalam> (raw)
In-Reply-To: <alpine.LSU.2.01.1008180049370.17078@obet.zrqbmnf.qr>

On Wed, 18 Aug 2010 00:56:49 +0200 (CEST)
Jan Engelhardt <jengelh@medozas.de> wrote:

> On Wednesday 2010-08-18 00:44, Jonathan Tripathy wrote:
> >
> > When using a single Linux host with lots of bridges, would there ever be a
> > time, even for a few seconds, where traffic would "jump" bridges?
> >
> > I know a previous poster mentioned that when adding a host to a bridge, for a
> > few seconds all packets get sent everywhere
> 
> That seems unlikely. The bridge keeps a table of (mac, bridgeport) 
> tuples (cf. `brctl showmacs br0`), and a "broadcast" should only occur 
> when there is no matching entry or when the destination L2 address is 
> broadcast. (Ignoring multicast for now.)
> 
> > Reason I ask is that I am considering have one bridge for public traffic and
> > one bridge for private, and don't want private traffic to be seen by hosts
> > connected to the public bridge.
> 
> Bridges link Ethernet (sub)segments together to form a (large) Ethernet 
> segment. In other words, if you keep the trees separate, they will be 
> separate.

The forwarding database has aging so if a host does not send or receive
traffic for that interval (default is 5 minutes), then the entry is forgotten.
This is part of the 802.1d standard and is used to allow host to be moved
from one segment to another.

  reply	other threads:[~2010-08-17 23:34 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-17 22:44 Bridges Jonathan Tripathy
2010-08-17 22:56 ` Bridges Jan Engelhardt
2010-08-17 23:34   ` Stephen Hemminger [this message]
2010-08-18 11:27 ` Bridges Thomas Jacob
2010-08-18 19:51   ` Bridges Jonathan Tripathy
2010-08-18 21:51 ` Bridges Grant Taylor
2010-08-18 21:57   ` Bridges Jonathan Tripathy
2010-08-18 22:08     ` Bridges Grant Taylor
2010-08-18 22:15       ` Bridges Jonathan Tripathy
2010-08-18 22:26         ` Bridges Jan Engelhardt
2010-08-18 22:51           ` Bridges Jonathan Tripathy
2010-08-18 23:05             ` Bridges Pascal Hambourg
2010-08-18 23:07               ` Bridges Jonathan Tripathy
2010-08-18 23:21                 ` Bridges Pascal Hambourg
2010-08-18 23:23                   ` Bridges Jonathan Tripathy
2010-08-18 23:45                   ` Bridges Jonathan Tripathy
2010-08-19  7:26                     ` Bridges Pascal Hambourg
2010-08-19 18:47                       ` Bridges Jonathan Tripathy
2010-08-19 19:26                         ` Bridges Pascal Hambourg
2010-08-19 19:37                           ` Bridges Jonathan Tripathy
2010-08-19 20:00                             ` Bridges Jan Engelhardt
2010-08-19 20:11                               ` Bridges Jonathan Tripathy
2010-08-19 21:14                             ` Bridges Pascal Hambourg
2010-08-19 21:24                               ` Bridges Jonathan Tripathy
2010-08-19 22:04                                 ` Bridges Pascal Hambourg
2010-08-19 22:53                                   ` Bridges Jonathan Tripathy
2010-08-20  8:53                                     ` Bridges Pascal Hambourg
2010-08-21 21:46                                       ` Bridges Jonathan Tripathy
2010-08-21 23:25                                         ` Bridges Jan Engelhardt
     [not found]                                           ` <4C70E853.6050107@abpni.co   .uk>
2010-08-22  9:05                                           ` Bridges Jonathan Tripathy
2010-08-22  9:09                                             ` Bridges Jan Engelhardt
     [not found]                                               ` <4C70E 9A2.3040907@abpni.co.uk>
2010-08-22  9:10                                               ` Bridges Jonathan Tripathy
2010-08-22 21:02                                                 ` Bridges Pascal Hambourg
     [not found]                                                   ` <4C7194 D3.7070803@abpni.co.uk>
2010-08-22 21:21                                                   ` Bridges Jonathan Tripathy
2010-08-23  8:22                                                     ` Bridges Pascal Hambourg
2010-08-23 20:18                                                       ` Bridges Jonathan Tripathy
2010-08-24  8:57                                                         ` Bridges Karel Rericha
2010-08-24 14:44                                                         ` Bridges Pascal Hambourg
2010-08-24 17:37                                                           ` Bridges Jonathan Tripathy
2010-08-24 18:07                                                             ` Bridges Pascal Hambourg
2010-08-24 18:34                                                               ` Bridges Jonathan Tripathy
2010-08-24 22:20                                                                 ` Bridges Pascal Hambourg
2010-08-20  8:38                                   ` Bridges Jan Engelhardt
2010-08-20  9:05                                     ` Bridges Pascal Hambourg
2010-08-20  9:09                                       ` Bridges Jan Engelhardt
2010-08-20 10:26                                         ` Bridges Pascal Hambourg
2010-08-20 16:02                                           ` Bridges Grant Taylor
2010-08-20 16:18                                             ` Bridges Jan Engelhardt
2010-08-20 16:25                                               ` Bridges Grant Taylor
2010-08-20 16:32                                                 ` Bridges Jan Engelhardt
2010-08-21 12:48                                             ` Bridges Pascal Hambourg
2010-08-21 21:44                                               ` Bridges Grant Taylor
2010-08-19 19:28                         ` Bridges Jan Engelhardt
2010-08-18 22:59   ` Bridges Pascal Hambourg
2010-08-18 23:00     ` Bridges Jonathan Tripathy
2010-08-18 23:11       ` Bridges Pascal Hambourg
2010-08-19  8:29       ` Bridges Jan Engelhardt
2010-08-19  9:16         ` Bridges Pascal Hambourg
2010-08-19  3:52     ` Bridges Grant Taylor
2010-08-19  7:33       ` Bridges Pascal Hambourg
2010-08-19 14:51         ` Bridges Grant Taylor
2010-08-19 14:56           ` Bridges Jan Engelhardt
2010-08-19 15:49             ` Bridges Grant Taylor
2010-08-19 16:21               ` Bridges Jan Engelhardt
2010-08-19 16:41                 ` Bridges Grant Taylor
2010-08-19 17:10                   ` Bridges Jan Engelhardt
2010-08-19 18:36                     ` Bridges Grant Taylor
2010-08-19 17:10                   ` Bridges Rick Jones

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