Frame-relay the final frontier!

————————
Frame-relay
————————

facts:

CIR = committed information rate guaranteed bandwidth.
DTE = default of cisco routers
DCE = ISP side of the serial interface (clock rate)
PVC = permanent virtual circuit
SVC = switches virtual circuit
NBMA = non-broadcast multiaccess Topology
Broadcast = ethernet broadcast topology.
PVC full mesh
PVC partial mesh
Hub and spoke topology.
————————
———————————
lmi – heartbeat hello keepalive
———————————

lmi = local management interface message.
DCE(clock rate) –> DTE (default router)
PVC status – Active/Inactive.

3 lmi types
cisco
ansi
q933a

—————————
lmi autosense used:
—————————
The DTE device pumps 3 lmi types to the DCE and then the DCE
returns the correct lmi type and then both agree and keep correct lmi type.
config-if)#frame-relay lmi-type (cisco, ansi, q933a)

——————————————————-
About the DLCI
——————————————————-

DCLI layer 2
locally used  or locally significant
could use same DCLI on all routers
airplane theory example (gates to fly into)

Dynamic- inverse-ARP is used.
frame-relay interface-dlci 123
Static – Static
frame-relay map ip (remote ip)(local dlci) broadcast
split-horizon issues on frame-relay
pic of hub spoke and split-horizon
R2 R1 R3. Router 2 sends updates to R1 and then R1 has to then send update
out same interface to R3. split-horizon prevents this.

————-
subif

– multipoint
– point-to-point
Split-horizon turn off/on at interface level:

int serial0
config-if)#ip split-horizon
config-if)#no ip split-horizon
—————————
Show frame-relay pvc satus
—————————-

#show frame-relay pvc status

Active – all working
Inactive – remote device not config correctly.
Deleted – Local issue on router.

—————————————————
Pic of frame hub and spoke Lab
—————————————————


———
R1 Config
———
interface Serial1
 description Points to R1 and R2
 no ip address
 encapsulation frame-relay
 ip split-horizon
 no frame-relay inverse-arp
 frame-relay lmi-type cisco
!
interface Serial1.12 point-to-point
 ip address 172.12.123.1 255.255.255.252
 ip ospf authentication message-digest
 ip ospf message-digest-key 1 md5 ccie
 ip ospf network non-broadcast
 frame-relay interface-dlci 112  
!
interface Serial1.13 point-to-point
 ip address 172.12.123.5 255.255.255.252
 ip ospf network non-broadcast
 frame-relay interface-dlci 113  

———
R2 Config
———
interface Serial1
 description Points to R1
 ip address 172.12.123.2 255.255.255.252
 encapsulation frame-relay
 ip ospf authentication message-digest
 ip ospf message-digest-key 1 md5 ccie
 ip ospf priority 0
 frame-relay map ip 172.12.123.1 211 broadcast
 no frame-relay inverse-arp
 frame-relay lmi-type cisco

———-
R3 Config
———-
interface Serial1
 ip address 172.12.123.6 255.255.255.252
 encapsulation frame-relay
 ip ospf priority 0
 frame-relay map ip 172.12.123.5 311 broadcast
 no frame-relay inverse-arp
 frame-relay lmi-type cisco
——————
Multipoint example – similar to physical serial interface.
——————
interface Serial1
 description Points to R1 and R2
 no ip address
 encapsulation frame-relay
 ip split-horizon
 no frame-relay inverse-arp
 frame-relay lmi-type cisco
interface Serial1.14 multipoint
 ip address 172.12.123.18 255.255.255.252
 frame-relay map ip 172.12.123.6 112 broadcast

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