route withdrawals are not sent upon protocol removal

[Ondrej Zajicek]

On Wed, Jun 06, 2018 at 01:33:53PM +0100, Thomás S. Bregolin wrote:
> Hello,
> 
> 
> On Tue, Jun 5, 2018 at 3:43 PM, Thomás S. Bregolin <thoms3rd at gmail.com>
> wrote:
> 
> > On Tue, Jun 5, 2018 at 2:13 PM, Jan Maria Matejka <jan.matejka at nic.cz>
> > wrote:
> >
> >> Could you please try the attached script or try to create some reproducer
> >> for me
> >> to see the bug clearly?
> >>
> >
> > I will give the test-withdraw script a go and reply with more information.
> >
> 
> I've attached a modified version of the test-withdraw script showing the
> issue. It seems my problem is related to the "start delay time" option.
> When I set it to 1, sometimes the withdrawal is sent, and sometimes it
> isn't. However, when it *isn't* sent, it is *never* sent, no matter how
> long I wait. The problem is solved by setting the timeout to a higher
> value, or using the default 5 seconds.

Hello

Note that in the modified version no protocols are removed, both testproto
and testproto2 are still configured and running. Just the BGP export
filter was changed, and because 'configure soft' was used, then it was
not reloaded. That is expected.

But it is likely that if both changes happen simultaneously, i.e. a
static protocol is removed and a BGP export filter is changed to no
longer allow routes from that protocol, then withdraws are not sent. This
is likely a bug, could be avoided by not doing both protocol removal and
export filter change at the same time.

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."