Re: maximum ipv4 bgp prefix length of /24 ?

[Jon Lewis <jlewis () lewis org>]

On Mon, 2 Oct 2023, Jakob Heitz (jheitz) via NANOG wrote:

> While I did allude to some of the complexity, my main point
>
> is that FIB compression does not allow you to install a FIB with less memory.
>
> Because you must be prepared for transients during which the FIB needs to store
>
> mostly uncompressed anyway.
>
> All it does is to increase convergence time.

In my experience, that's incorrect.  FIB compression allows you to run 
with full tables on devices that can no longer accommodate full 
[uncompressed] tables in whatever is used to store FIB.  Obviously, it 
does require more RAM due to the complexities of keeping track of more 
state.  But RAM is typically far more easily upgraded (cheaply) than TCAM.

Even if it does increase convergence time, that's a compromise many 
are willing to make if the alternative is toss your current gear and 
replace it with newer gear years sooner.

----------------------------------------------------------------------
 Jon Lewis, MCP :)           |  I route
 StackPath, Sr. Neteng       |  therefore you are
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