CCIE Pursuit Blog

April 4, 2008

Internetwork Expert Volume II: Lab 3 – Section 8

QoS – 6 Points

8.1 FRTS

Configure FRTS with these parameters:

Data should be sent at a sustained rate of 256Kbps per DLCI.  <-CIR
In the event of congestion noticification fallback to no lower than 192Kbps  <-MINCIR with adaptive-shaping becn
Any FECNs received should be reflected back as a BECN. <-???

Not too hard to figure out the third one :-0

r1(config-map-class)#frame ?
  fecn-adapt         Enable Traffic Shaping reflection of FECN as BECN

frame-relay cir

frame-relay mincir

frame-relay adaptive-shaping

becn
 Enables rate adjustment in response to backward explicit congestion notification (BECN).

r1(config-map-class)#do sh run | sec FRTS
map-class frame-relay FRTS
 frame-relay cir 256000
 frame-relay mincir 192000
 frame-relay adaptive-shaping becn
 frame-relay fecn-adapt

Since we want to apply this to ALL DLCIs we just need two commands under the FR int:

r1(config-map-class)#int s0/0/0
r1(config-if)#frame traffic-shaping  <-don’t forget this!!!
r1(config-if)#frame class FRTS

r1(config-if)#do sh traffic

Interface   Se0/0/0
       Access Target    Byte   Sustain   Excess    Interval  Increment Adapt
VC     List   Rate      Limit  bits/int  bits/int  (ms)      (bytes)   Active
103           256000    4000   256000    0         125       4000      BECN
104           256000    4000   256000    0         125       4000      BECN
105           256000    4000   256000    0         125       4000      BECN
106           256000    4000   256000    0         125       4000      BECN
107           256000    4000   256000    0         125       4000      BECN
108           256000    4000   256000    0         125       4000      BECN
109           256000    4000   256000    0         125       4000      BECN
—output truncated—

8.2 Rate Limiting

Limit HTTP responses out r4’s fa0/1 to 256Kbps between the hours of 8am to 5pm Monday through Friday.

We need to build a time-range first:

time-range
http://www.cisco.com/en/US/docs/ios/12_3t/fun/command/reference/cfrgt_12.html#wp1058115

r4(config)#time-range TASK82
r4(config-time-range)#periodic weekdays 08:00 to 17:00

NOTE: Clarify with the proctor about the start and end time (17:00 versus 16:59)

Now let’s match HTTP in an (extended named) access-list:

ip access-list extended TASK82
 permit tcp any eq www any time-range TASK82

Let’s pop that sucker into a class-map:

class-map match-all TASK82
 match access-group name TASK82

Then match that class in a policy-map and apply our policing:

policy-map TASK82
 class TASK82
    police 256000

Finally let’s put this on the interface:

r4(config)#int fa0/1
r4(config-if)#service-policy out TASK82

The reason that I use consistent naming throughout the process is so that I can quickly look at my configuation:

r4(config-if)#do sh run | sec TASK82
class-map match-all TASK82
 match access-group name TASK82
policy-map TASK82
 class TASK82
    police 256000
 service-policy output TASK82
ip access-list extended TASK82
 permit tcp any eq www any time-range TASK82
time-range TASK82
 periodic weekdays 8:00 to 17:00

IE uses:

policy-map TASK82
 class TASK82
    police cir 256000

Not sure why?

Task 8.2 quick question

With ‘police 256000’:

r4#sh policy-map int fa0/1
 FastEthernet0/1

  Service-policy output: TASK82

    Class-map: TASK82 (match-all)
      0 packets, 0 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: access-group name TASK82
      police:
          cir 256000 bps, bc 8000 bytes
        conformed 0 packets, 0 bytes; actions:
          transmit
        exceeded 0 packets, 0 bytes; actions:
          drop
        conformed 0 bps, exceed 0 bps

    Class-map: class-default (match-any)
      84 packets, 7949 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: any

With ‘police cir 256000’:

r4#sh policy-map int fa0/1
 FastEthernet0/1

  Service-policy output: TASK82

    Class-map: TASK82 (match-all)
      0 packets, 0 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: access-group name TASK82
      police:
          cir 256000 bps, bc 8000 bytes
        conformed 0 packets, 0 bytes; actions:
          transmit
        exceeded 0 packets, 0 bytes; actions:
          drop
        conformed 0 bps, exceed 0 bps

    Class-map: class-default (match-any)
      101 packets, 9793 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: any

Any differences?

police

r4(config-pmap-c)#police ?
  <8000-2000000000>  Bits per second
  cir                Committed information rate
  rate               Specify police rate

8.3 Signalling

“…administrators have configured the client applications on these vlans to requrest bandwidth reservations…”

RSVP….Integrated Services

The good news is that RSVP is ridiculously easy to configure:

ip rsvp bandwidth

r4(config)#int s0/0/0
r4(config-if)#ip rsvp band 128 64

r4#sh ip rsvp int s0/0/0
interface    allocated  i/f max  flow max sub max
Se0/0/0      0          128K     64K      0

There is one ‘gotcha’ though: You need to enabled WFQ for RSVP.  When you turn on FRTS, WFQ is disabled.  You need to explicitly set it.

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