Learning by Doing: CISCO Certified Network ... - SCN Research

in DE pkts 0 out DE pkts 0
out bcast pkts 18 out bcast bytes 1152
pvc create time 00:23:24, last time pvc status changed 00:16:49
DLCI = 18, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE,
INTERFACE = Serial0/0
input pkts 54 output pkts 53 in bytes 4472
out bytes 4364 dropped pkts 0 in FECN pkts 0
in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
in DE pkts 0 out DE pkts 0
out bcast pkts 21 out bcast bytes 1344
pvc create time 00:23:18, last time pvc status changed 00:19:50
Notice you are on “timothy” which uses dlci #16 to connect to the Adtran. When
you do a sh frame pvc you see the status of dcli #17 and #18…the other two
dlci’s.
Challenge Lab or Supplemental Activities:
1. Change the map statements to reflect a “full-mesh” topology. Note any
differences in pvc’s, ip routes, etc.
2. Why do we need to use the same subnet over all three frame relay interfaces?
I thought we needed separate subnet numbers on each?
3. Put an error on the serial interface on the hub router (timothy—shut down the
interface, remove the lmi type, etc). See if you can still get connectivity
between all three routers. What about connectivity between allen and Lloyd?
So what have I learned here?
So far we have learned that frame relay is just another encapsulation that we can use on a
serial interface (which is HDLC by default). In this lab you have learned to set up a “hub
and spoke” frame relay network. Each router is connected with a circuit to a master
router that contains maps to all others. We do this to save money because each circuit
connection costs money. Obviously if we can purchase two frame relay circuits instead
of three then we would be saving money. In the next lab you will learn how to configure
a full-mesh frame relay network using subinterfaces.
Guest Router Name Derivation
Timothy Lloyd Allen was a chief network program designer for Omega Engineering
Corp (New Jersey) who was sentenced to 41 months in prison for unleashing a $10
million “time bomb” within a manufacturing software program he helped design. After
11 years with the company he was “suddenly laid off,” but, ha-ha, he would “get his
revenge.” And boy did he. Now he’s got to hope he finds a bigger boy friend than
everyone else. Won’t shower time be fun?
398