On Fri, Sep 26, 2014 at 01:36:24PM +0100, Stuart Henderson wrote:
> On 2014/09/26 07:42, Alexander Hall wrote:
> > Before performing a dhcp request, /etc/netstart explicitly takes the
> > interface down. As noted (by me) at g2k14, and also at work, this results
> > in a significant delay in getting the address.
> >
> > I'm not all into enterprise switch magic, but someone hinted that this
> > could come from the switch reinitializing the port, with all kinds of
> > spanning-tree magic etc involved.
>
> No magic - it just doesn't forward for a certain number of seconds
> while it listens for incoming spanning-tree BPDUs. Switch config is
> dubious though, normally you would use "switchport mode access" and
> "spanning-tree portfast" or equivalent on access ports. (HP Procurve
> switches have a different, less intrusive, default where they do
> listen for BPDUs but only for 3 seconds, so you don't usually need
> to fiddle with them).
>
> > Looking at the history of pre-dhclient ' down' in /etc/netstart
> > (introduced in -r1.43, 18 Sep 1998 18:42:10), I cannot see a reason
> > for keeping it.
> >
> > This cuts 'sh /etc/netstart' time from ~minute to ~nothing at work.
> >
> > OK?
>
> Commit log was "apply media directives on dhcp interfaces" - I'm
> wondering if there may be NICs that only reset media if they
> are brought down+up. However if that is the case, the user could
> add 'down' to the hostname.if line themselves..
>
> I think this would only be a problem where you re-run netstart
> when the system is already up; does that match your experience?
>
I think this is no longer needed. If there are some old drivers that still
do that then we should just fix them.
This diff is OK by me.
>
> > /Alexander
> >
> >
> > Index: netstart
> > ===================================================================
> > RCS file: /cvs/src/etc/netstart,v
> > retrieving revision 1.141
> > diff -u -p -r1.141 netstart
> > --- netstart 12 Jul 2014 14:39:31 -0000 1.141
> > +++ netstart 26 Sep 2014 05:32:22 -0000
> > @@ -63,7 +63,7 @@ ifstart() {
> > [ "$name" = "NONE" ] && name=
> > [ "$mask" = "NONE" ] && mask=
> > [ "$bcaddr" = "NONE" ] && bcaddr=
> > - cmd="ifconfig $if $name $mask $bcaddr $ext1 $ext2 down"
> > + cmd="ifconfig $if $name $mask $bcaddr $ext1 $ext2"
> > cmd="$cmd;dhclient $if"
> > dhcpif="$dhcpif $if"
> > ;;
> >
> >
>
--
:wq Claudio
