CCNA认证考试-collectedfromBraindumps--1-
the five steps of encapsulation:
1) user information is converted to data.
2) data is converted to segments.
3) segments are converted to packets or datagrams.
4) packets or datagrams are converted to frames.
5) frames are converted to bits.
what kind of services are provided by the presentation layer ?
jpeg, tiff, pict, ebcdic to ascii, midi, mpeg, quicktime
what kind of services are provided by the session layer ?
nfs, sql, rpc, x windows, asp, dna scp
how to enable a banner on a cisco router ?
router(config#) banner motd #
what are the three ways to display ipx interface e0 ?
sh ipx int e0
sh ipx interface e0
sh ipx interface ethernet0
what are the three ways to modify your running-configuration file ?
???
what s the default subnet mask for class a, b and c ip adresses ?
class a 255.0.0.0
class b 255.255.0.0
class c 255.255.255.0
which ip-class provides the least number of hosts?
class c
how to define access-list commands ?
wrong: router(config-if)# access-list 1 permit 172.16.20.1 0.0.0.0
right: router(config) # access-list 1 permit 172.16.20.1 0.0.0.0
the access list will be defined at global level, not at the interface level. it’s a small but important detail. the access group command will be defined at interface level:
router(config) # int e0
router(config-if) # access-group 1 out