6.2.b Implement, optimize and troubleshoot QoS using MQC

  • 6.2.b [ii] Network based application recognition [NBAR]
  • 6.2.b [iii] Marking using IP precedence, DSCP, CoS, ECN

ripv2

put nbar on f0/0 of r2

R2#sh run | sec 0/0
interface FastEthernet0/0
ip address 192.168.12.2 255.255.255.0
ip nbar protocol-discovery

ping r4

R4#ping 4.4.4.4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 4.4.4.4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 8/8/8 ms

look at nbar on r2

R2#sh ip nbar protocol-d proto icmp

FastEthernet0/0

Last clearing of “show ip nbar protocol-discovery” counters 00:05:45

Input                    Output
—–                    ——
Protocol                 Packet Count             Packet Count
Byte Count               Byte Count
5min Bit Rate (bps)      5min Bit Rate (bps)
5min Max Bit Rate (bps)  5min Max Bit Rate (bps)
———————— ———————— ————————
icmp                     0                        0
0                        0
0                        0
0                        0
Total                    15                       99

make a class map for icmp on r2

R2#sh class-map ICMP-CLASS
Class Map match-all ICMP-CLASS (id 1)
Match protocol  icmp

put a policy on the class to mark it with dscp

R2#sh policy-map
Policy Map ICMP-POLICY
Class ICMP-CLASS
set dscp af41

put a service policy input on the interface

R2#sh run int f0/0
Building configuration…

Current configuration : 147 bytes
!
interface FastEthernet0/0
ip address 192.168.12.2 255.255.255.0
ip nbar protocol-discovery
duplex full
service-policy input ICMP-POLICY

R2#sh policy-map int
FastEthernet0/0

Service-policy input: ICMP-POLICY

Class-map: ICMP-CLASS (match-all)
25 packets, 2850 bytes
5 minute offered rate 0000 bps, drop rate 0000 bps
Match: protocol icmp
QoS Set
dscp af41
Packets marked 25

prove it with wireshark also

ws_dscp