mailing list archives
Re: Common operational misconceptions
From: Andreas Echavez <andreas () livejournalinc com>
Date: Thu, 16 Feb 2012 13:27:08 -0700
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
*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
*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
*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.
On Wed, Feb 15, 2012 at 1:47 PM, John Kristoff <jtk () cymru com> wrote:
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.