[c-nsp] network rebuild questions

[Phil Bedard]

Are you doing L3 everywhere or are the 3550s Layer 2?  Why 5 pairs of  
3550s?  Why 4 route reflectors?

The hardware is ancient and I think you'll have a hard time doing full  
BGP tables on them without doing route filtering.  With your traffic  
levels I don't think you would require DFCs or SFMs.

Phil


On Oct 31, 2009, at 12:50 PM, Bill Desjardins wrote:

> Hi all,
>
> First, sorry a bit long here with a bunch of questions...
>
> I have a small ISP (~50 customers) and am in the process of
> building out a new network. traffic runs ~250Mbit in/out
> with ~230k PPS in/230k PPS out. 3 providers, all gig uplinks. the
> network does nothing fancy, no MPLS, no QOS, etc. just basic routing.
>
> the soon to be smelted network consists of a pair of 6506's/SUP1's  
> which
> each get a full BGP feed and contain customer SVI's w/HSRP.  
> connected to
> these are 2 5500's for customer connections. all layer2.
>
> the new core tier is a pair of 6509/(2)SUP2/(2)6516+DFC/6548/(2)SFM
> with 5 pairs of 3550's (12T's & G's) hanging off those via p2p fiber
> in a U-shape configuration for the access. eg:
>
> coreA <--> 3550 <--> 3550 <--> coreB.
>
> there are 4 2651XM/256MB route-reflectors which handle only customer
> assigned subnets from the 3550's with a few customers doing ebgp to  
> the
> the access layer. the RR's also do some basic traffic engineering via
> community assignments and get BOGON bgp feeds.
>
> The IGP is ospf and handles only loopbacks and the p2p links between
> everything. all /31's and all from a single /26.
>
> for my uplinks, I've decided to go with separate border routers for
> each provider. I am planning to use 6503/SUP2/(2)6516 taking limited
> BGP (~240k routes) + default. should I be peering each brdr with each
> other? if so, should they be p2p direct to each other in addition to
> connected via the core?
>
> wrt to default routes, should they come from the brdrs via ospf
> default-originate or would propagating default via ibgp to the edge be
> preferred?
>
> what's your experience with SFM+DFC's? are they worth the extra  
> complexity?
>
> some sup2 specific questions....
>
> I am currently running 12.2(18)SXF14 and would like to hear any  
> thoughts
> on your experiences with the stability of the SXF branch for the  
> SUP2's.
>
> at my traffic level's, how much further can the sup2's go?
> is there any critical traffic level/pps line I shouldnt cross?
>
> How far can I push the FIB table? iirc, the pfc2 can handle 259k cef
> entries. Ive got my bgp tuned to ~245k routes and "sh ip cef sum"
> shows 250k entries. Is this pushing it too close to hitting software
> switching? I'm not seeing any complaints in the log about fib table
> drops.
>
> wrt to CEF, any recommendations on configuring it or what I should
> not/never be doing?
>
> single/dual sup's...  What has been your real-world experience with
> sup2 failover using SSO/NSF? any gotchas with SSO/NSF and the
> SFM+DFC's?I would rather have the chassis completely die vs
> having it upset the network until its fixed.
>
> many thanks for your time if you made it this far!
>
> Best,
>
> Bill
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