Re: Simplify bridge(4)

[John Nemeth <jnemeth%cue.bc.ca@localhost>]

On Feb 12, 10:33am, Roy Marples wrote:
} On 12/02/2016 08:34, Ryota Ozaki wrote:
} > On Thu, Feb 11, 2016 at 3:17 AM, Mouse <mouse%rodents-montreal.org@localhost> wrote:
} >>> [J]ust wondering if we are going to see vether(4) anytime soon.
} >>
} >> How would this vether differ from the existing tap?  Presumably I'm
} >> just missing something....
} > 
} > dhcpcd didn't work well with bridge(4) and tap(4) didn't help that.
} > vether(4) would help that. We may be able to address the issue by
} > fixing bridge or tap but I have no idea for now.
} 
} It's not actually dhcpcd itself - it's the kernel BPF implementation.
} There was also an issue where some DHCPv6 messages were not following
} across the bridge properly either.
} 
} If vether solves that then great, but does that mean we could drop the
} tap interface entirely or just swap it in place?
} From my perspective (a user), there is no difference between tap and vether?

     tap(4) is a direct interface between userland and the network.
vether(4) would not be (although you could use BPF, etc.).  It
would be an ethernet device that represents the host.  If you know
how to configure Cisco devices, think BVI.

     The problem with bridge(4) is that you put addresses on one
of the interfaces included in the bridge.  The addresses belong to
the host as a whole, not to the particular part represented by an
interface to part of the outside world.  vether(4) would represent
the host.  "bridge" is a synonym for "switch".  A bridge is really
network infrastructure, not part of a host.

}-- End of excerpt from Roy Marples