[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: OpenBGP nexthop

On Wed, Apr 12, 2006 at 01:36:46PM +0200, Sylvain Coutant wrote:
> > What was the state of the parent interface and what kind of interface is
> > it?
> Bge driver. It was up and running : BGP sessions were established
> through the vlans reported as invalid by OpenBGP.

I bet Henning's diff will fix this.

> > ifconfig down should not crash the box. Panic message and trace would be
> > interesting.
> It was remote and we did a hard reboot without console access. Log files
> were empty.


> > No, the session and the nexthop are two different things.
> I agree. My point is : how to prevent routing loops in such cases ?

How should routing loops happen if you do not announce those invalid
routes? Prefixes with an invalid netxhop are not used and are not

> Whatever triggered the case (a link down for any reason or a bug) is not
> so important. Announcing routes over the Internet and creating a routing
> loop for those routes is important.
> It could be one more setting that, if set to yes, would drop the session
> if it receives an unreachable nexthop ... just an idea. It could default
> to yes for eBGP session and no for iBGP sessions. Would that fit most of
> "usual" cases ?

No way. This is not how BGP works and will break in many cases.

:wq Claudio

Visit your host, monkey.org