[149859] in North American Network Operators' Group
Re: Common operational misconceptions
daemon@ATHENA.MIT.EDU (Andreas Echavez)
Thu Feb 16 15:28:20 2012
In-Reply-To: <20120215144715.18e65a55@w520.localdomain>
From: Andreas Echavez <andreas@livejournalinc.com>
Date: Thu, 16 Feb 2012 13:27:08 -0700
To: John Kristoff <jtk@cymru.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
I'm surprised I haven't seen QoS mentioned! If you're teaching college
students, you might want to go over stuff that directly relates to what
they're doing at home, or misconceptions they might make in a small
WAN/ISP environment.
*Why disabling ICMP doesn't increase security and only hurts the web* *(path
MTU discovery, diagnostics)
*How NAT breaks end-to-end connectivity (fun one..., took me hours to
explain to an old boss why doing NAT at the ISP level was horrendously
wrong)
*Not to be afraid of ACLs on an edge router. Understanding what
does/doesn't affect cpu utilization
*Layer 3 Switch vs Router. Old concepts like switch vs router need to be
clarified...
*When vendors and numbers lie ;) aka *oversubscription*!
*MAC is not security
*Irrelevant security concepts (smurf attacks, ping of death). More focus
should be on real modern day security concerns, like layer 7 exploits,
router software 0days, VLAN hopping, and UDP floods and BGP spoofing. This
might be a good place to explain why downloading IOS firmware from
thepiratebay is a bad idea :)
This is just coming from a sysadmin who likes to play with network gear and
once endured college networking classes.
Thanks!
Andreas
On Wed, Feb 15, 2012 at 1:47 PM, John Kristoff <jtk@cymru.com> wrote:
> Hi friends,
>
> As some of you may know, I occasionally teach networking to college
> students and I frequently encounter misconceptions about some aspect
> of networking that can take a fair amount of effort to correct.
>
> For instance, a topic that has come up on this list before is how the
> inappropriate use of classful terminology is rampant among students,
> books and often other teachers. Furthermore, the terminology isn't even
> always used correctly in the original context of classful addressing.
>
> I have a handful of common misconceptions that I'd put on a top 10 list,
> but I'd like to solicit from this community what it considers to be the
> most annoying and common operational misconceptions future operators
> often come at you with.
>
> I'd prefer replies off-list and can summarize back to the list if
> there is interest.
>
> John
>
>
