[c-nsp] bgp scalability C7600

[Mark Tinka]

On 8/Feb/15 05:02, Paul wrote:
> It's not as bad as everyone is saying. Have one with 6 full feeds (3
> million paths, 800k attribute entries).
> As long as you are using relatively new code (such as SXJ on 6500),
> it's not too bad.  The 2 biggest problems is the hardware FIB update
> and RAM.  The platform runs out of RAM due to 1g limitation, and
> hardware FIB updates are very slow, especially the mcast to the DFCs.

I'd tend to agree - your biggest issues with the platform (as with the
XR12000's we had in the past) is how young (and stable) the code is, and
how much control plane memory you're left to play with after the code boots.

FIB update niceness will depend a lot (but not only) on code quality.
The better the code, the more efficient this can happen. But running out
of RAM will cause massive cyclic issues that have nothing to do with the
FIB, which can be exacerbated by bad code. Then again, running out of
FIB with continual injection into it just sends the whole tower crashing.

So provided the SUP720 or RSP720 have enough RAM to run recent code that
has better inherent BGP optimization, as well as new BGP features such
as BGP-SD, scalability could be marginally improved in harsh
environments such as multiple iBGP full feeds and dozens of eBGP
downstreams and upstreams.

Personally, I barely have enough time as it is :-). But if these were
the platforms on-hand with little to no budget to replace them, a case
can be made.

Mark.