Internetwork Expert Volume II: Lab 9 – Section 2

WAN Technologies – 8 Points

2.1 Partial Mesh

Subinterfaces on r3 and r4 – should I use ptp or ptm?  I read ahead to IGP to see if there’s anything that forces ptm, but I didn’t find anything.  Looks like I can use ptp.

Interesting Frame Relay network.

2.2 Point-to-Point

CCOnlinelabs throws a TON of DLCIs at you:

r3(config-if)#do sh frame pvc | i Serial0/1/0
PVC Statistics for interface Serial0/1/0 (Frame Relay DTE)
DLCI = 311, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 312, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 314, DLCI USAGE = UNUSED, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 315, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 316, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 317, DLCI USAGE = UNUSED, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 318, DLCI USAGE = UNUSED, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 319, DLCI USAGE = UNUSED, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 331, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 332, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 334, DLCI USAGE = UNUSED, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 335, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 336, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 337, DLCI USAGE = UNUSED, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 338, DLCI USAGE = UNUSED, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0
DLCI = 339, DLCI USAGE = UNUSED, PVC STATUS = ACTIVE, INTERFACE = Serial0/1/0

interface Serial0/1/0
 description ->FR PTP r5
 ip address 148.1.35.3 255.255.255.0
 encapsulation frame-relay
 shutdown
 no frame-relay inverse-arp IP 311
 no frame-relay inverse-arp IP 312
 no frame-relay inverse-arp IP 314
 no frame-relay inverse-arp IP 316
 no frame-relay inverse-arp IP 317
 no frame-relay inverse-arp IP 318
 no frame-relay inverse-arp IP 319
 no frame-relay inverse-arp IP 331
 no frame-relay inverse-arp IP 332
 no frame-relay inverse-arp IP 334
 no frame-relay inverse-arp IP 335
 no frame-relay inverse-arp IP 336
 no frame-relay inverse-arp IP 337
 no frame-relay inverse-arp IP 338
 no frame-relay inverse-arp IP 339
end

Whew!!!  🙂

 2.3 Point-to-Point

Very easy task.

2.4 Network Redundancy

If line protocol of the Frame-Relay subinterface goes down, then fire up a backup serial interface. 

In this case the subint goes down (but not the phys int) when we shut s0/0/0 on r1:

Serial0/0/0                unassigned      YES unset  up                    up
Serial0/0/0.401            148.1.0.4       YES manual down                  down

So we don’t need to worry about FREEK.

ARRGH!!! I have to use 12.3 documentation because Cisco has royally fucked up the 12.4 docs.

backup interface

backup delay

backup delay {enable-delay-period | never} {disable-delay-period | never}

r4(config-subif)#backup del 0 300

First value is the delay (in seconds) in bringing up the backup, the second value is the delay in dropping the backup when the primary path returns.  (default is 0 seconds for both)

I don’t know of a way of seeing the disable delay (outside of looking at the int config) but the “show backup” command will show the number of seconds remaining on the disable delay after the primary path returns:

r4#sh backup
Primary Interface   Secondary Interface   Status
—————–   ——————-   ——
Serial0/0/0.401     Serial0/1/0           waiting to revert (290 more seconds)