Re: BGP terminology question

[Tony Li <tony.li () tony li>]

> > I understand BGP flapping to be announcements followed by  
> > withdraws over a short period.  I am seeing a peer with a large  
> > number of announcements and the normal number of withdraws.  Is  
> > there a term to describe what I am seeing?  I'd like to understand  
> > what is happening, but I've been looking for more info and can't  
> > seem to find anything. I suspect I am just not using the right  
> > words to search.
> >
> > If there isn't a term, why would a peer announce thousands of time  
> > an hour with very few withdraws?
>
> There is a term, it's called "broken".
>
> A peer should never announce a route it has already announced  
> unless that route is withdrawn.  (If the session goes down or is  
> reset, that counts as a withdrawal.)


There's another term for that behavior.  It's called "compliant".

There are a number of good implementation reasons why it is  
reasonable for an implementation to announce a route that it has  
already announced (e.g., peer groups).  Admittedly announcing  
thousands of times an hour does NOT seem reasonable, but 'never' is  
not a requirement of the BGP spec either.

Tony