Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
33 Cards in this Set
- Front
- Back
|
What does NBMA stand for? |
non broadcast multi access |
|
|
what is frame relay |
a multicast WAN network based on permanent virtual circuits |
|
|
what does pvc stand for? |
permanent virtual circuit |
|
|
what is lmi? |
local management interface protocol, similar to ppp's lcp. It sends status inquiry messages with keepalives and also alerts dte's of other dte's keepalive status |
|
|
what is dte & dce in the context of frame relay? |
the dte are the routers or end machines and dce is the switch. |
|
|
what is used for a data link layer address with frame relay? |
DLCI (data link connection identifier) which doesn't identify sender but identifies which virtual circuit it wishes to be sent to |
|
|
what is an svc? |
switched virtual circuit, like with dial up |
|
|
what is the cir? |
the rate at which bits mustbe sent over a vc according to contract |
|
|
What specification defines the frame relay header? |
LAPF - link access procedure frame bearer service |
|
|
how large is the default LAPF header? |
10bit dlci header |
|
|
what two options existed to define a protocol field for the header? |
ciscos 2 byte protocol field, which matches hldc values or RFC 1490 multiprotocol interconnect via frame relay |
|
|
do encapsulation issues affect the switch? |
no they only matter on dte's? |
|
|
do lmi messages matter to endpoints? |
they do not have to match with each other, they only matter between themselves and the dce |
|
|
what three protocols exist for lmi? |
cisco, ansi, itu(q933a) |
|
|
how does cisco configure lmi by default? |
via autosense |
|
|
what are the range of dlci's? |
usually 17-1000, low and high end reserved |
|
|
do dlci values have to be unique on all endpoints? |
No, they only have to be unique to one access link |
|
|
what determins which vc's can share an interface & ip address? |
only vc's that are fully meshed can exist on same subnet. |
|
|
how does one enable frame relay? |
encapsulation frame-relay |
|
|
how does one set the lmi-type? |
frame-relay lmi-type |
|
|
is lmi set per vc, sub interface, or interface? |
per interface |
|
|
how are dlci's learned? |
via lmi messages |
|
|
how are ip's on the other end of dlci's learned? |
inverse arp (which can then be used when figuring out what sub interfaces need which dlci) |
|
|
how are dlci's mapped to ip's?
|
For main interface or multipoint sub interfaces, the command frame-relay map ip dlci is used. For p2p sub interfaces, frame-relay interface-dlci |
|
|
how can encapsulation type be set for whole interface |
encapsulation frame-relay *ietf* |
|
|
how can encapsulation be set per vc? |
map command |
|
|
how can one see frame relay dlci's? |
show frame-relay pvc |
|
|
how can one see frame-relay mappings? |
show frame-relay map |
|
|
how does one define point to point or mulitpoint when creating sub interfaces? |
interface serial0/0/0.1 point-to-point |
|
|
what must be done on multipoint frame relay interfaces for ospf to work? |
network type must be changed to nonbroadcast |
|
|
What are l1/l2 tshooting steps? |
if line status down, likely l1. IF protocol status down, its lmi related and show frame-relay lmi or debug rame-relay lmi can be used |
|
|
What are tshooting steps for individual vc's? |
mapping can be checked with show frame-relay map. If correctly mapped, show frame-relay pvc will show if pcvc is active or inactive. |
|
|
If l1/l2 are up/up and the vc is active, what is next step? |
look for encapsulation mismatches |
