ACLs on routers slow throughput of a heavily used system resource. List two advantages of using ACLs. List a situation in which you might want to block (reject) certain traffic through an ACL on a router; that is, a situation in which the performance penalty would not be the deciding factor

What will be an ideal response?

(a)
Limit
traffic
for
a
closed
community.
(b)
Block
specific
known
attackers'
addresses
(e.g.,
single-­?point
denial
of
service).
The
real
issue
is
number.
Each
ACL
increases
the
work
of
the
router,
so
whereas
the
penalty
of
one
ACL
might
be
tolerable,
2
or
3
or
10
could
be
intolerable.
After
allowing
one
ACL,
it
is
difficult
to
deny
the
second,
and
so
on.
Rejecting
all
traffic
from
a
location
could
be
useful
for
blocking
an
attacker
from
a
known
address,
such
as
a
denial-­?of-­?service
attack
from
a
single
point.