Re: /27 the new /24

[Mel Beckman <mel () beckman org>]

Often I find that used Cisco gear is more reliable and just as affordable than newer gear with that tasty, flakey 
crust. I've had a terrible time with CCRs falling over with 1GB traffic while Cisco L3 3750s don't even breathe hard at 
10Gbps. I see no reason to use anything like 2500w even with Cisco gear. A dual Cisco 3750 stack consumes maybe 500W. 
Cisco firmware, for all its faults, seems to be much better tested than Mikrotik's. 

I once asked Mikrotik's support engineers how they performed regression testing, and they said "because we are a small, 
agile, disruptive innovator we don't follow old-school testing regimens. We're more interested in shipping affordable 
product." That's also their excuse for poor documentation. 

> From what I can see, "small, agile, disruptive innovator" is an excuse newer networking companies often give for 
> "sloppy, poorly tested, ill-conceived" product development. 



 -mel beckman

> On Oct 2, 2015, at 11:44 AM, Mike Hammett <nanog () ics-il net> wrote:
>
> Chances are the revenue passing scales to some degree as well. Small business with small bandwidth needs buys small 
> and has small revenue. Big business with big bandwidth needs buys big and has big revenue to support big router. 
>
> I can think of no reason why ten years goes by and you haven't had a need to throw out the old network for new. If 
> your business hasn't scaled with the times, then you need to get rid of your Cat 6500 and get something more power, 
> space, heat, etc. efficient. 
>
>
> I saw someone replace a stack of Mikrotik CCRs with a pair of old Cisco routers. I don't know what they were at the 
> moment, but they had GBICs, so they weren't exactly new. Each router had two 2500w power supplies. They'll be worse 
> in every way (other than *possibly* BGP convergence). The old setup consumed at most 300 watts. The new setup 
> requires $500/month in power... and is worse. 
>
> Stop using old shit. 
>
>
>
>
> ----- 
> Mike Hammett 
> Intelligent Computing Solutions 
> http://www.ics-il.com 
>
>
>
> Midwest Internet Exchange 
> http://www.midwest-ix.com 
>
>
> ----- Original Message -----
>
> From: "William Herrin" <bill () herrin us> 
> To: "Mike Hammett" <nanog () ics-il net> 
> Cc: "NANOG" <nanog () nanog org> 
> Sent: Friday, October 2, 2015 1:09:16 PM 
> Subject: Re: /27 the new /24 
>
> > On Fri, Oct 2, 2015 at 11:50 AM, Mike Hammett <nanog () ics-il net> wrote: 
> > How many routers out there have this limitation? A $100 router 
> > I bought ten years ago could manage many full tables. If 
> > someone's network can't match that today, should I really have 
> > any pity for them?
>
> Hi Mike, 
>
> The technology doesn't work the way you think it does. Or more 
> precisely, it only works the way you think it does on small (cheap) 
> end-user routers. Those routers do everything in software on a 
> general-purpose CPU using radix tries for the forwarding table (FIB). 
> They don't have to (and can't) handle both high data rates and large 
> routing tables at the same time. 
>
> For a better understanding how the big iron works, check out 
> https://www.pagiamtzis.com/cam/camintro/ . You'll occasionally see 
> folks here talk about TCAM. This stands for Ternary Content 
> Addressable Memory. It's a special circuit, different from DRAM and 
> SRAM, used by most (but not all) big iron routers. The TCAM permits an 
> O(1) route lookup instead of an O(log n) lookup. The architectural 
> differences which balloon from there move the router cost from your 
> $100 router into the hundreds of thousands of dollars. 
>
> Your BGP advertisement doesn't just have to be carried on your $100 
> router. It also has to be carried on the half-million-dollar routers. 
> That makes it expensive. 
>
> Though out of date, this paper should help you better understand the 
> systemic cost of a BGP route advertisement: 
> http://bill.herrin.us/network/bgpcost.html 
>
> Regards, 
> Bill Herrin 
>
>
>
>
> -- 
> William Herrin ................ herrin () dirtside com bill () herrin us 
> Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>