troubleshooting Question

How Telnet works in GRE Tunnel

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jskfanFlag for Cyprus asked on
RoutersNetworkingSwitches / Hubs
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How Telnet works in GRE Tunnel

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in the topology above I have created a GRE tunnel between R1 and R3. The configuration is shown below:
R1#show running-config 
Building configuration...

Current configuration : 2295 bytes
!
! Last configuration change at 09:31:13 CET Wed Sep 5 2018
!
version 15.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R1
!
boot-start-marker
boot-end-marker
!
aqm-register-fnf
!
!
no aaa new-model
clock timezone CET 1 0
mmi polling-interval 60
no mmi auto-configure
no mmi pvc
mmi snmp-timeout 180
!
!
!
!
!
!


!
!
!
!
ip cef
no ipv6 cef
!
multilink bundle-name authenticated
!
!
!
!
!
!
!         
!
!
redundancy
!
!
!
class-map match-all MAPMYGRE
 match access-group name MYGRE
class-map match-all MAPTELNET
 match access-group name MYTELNET
!
policy-map MYPOLICE
 class MAPTELNET
  police 128000
 class MAPMYGRE
!
! 
!
!
!
!
!
!         
!
!
!
!
!
!
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
interface Tunnel0
 ip address 172.16.13.1 255.255.255.0
 tunnel source 192.168.12.1
 tunnel destination 192.168.23.3
!
interface Ethernet0/0
 ip address 192.168.12.1 255.255.255.0
 service-policy output MYPOLICE
!
interface Ethernet0/1
 no ip address
 shutdown
!
interface Ethernet0/2
 no ip address
 shutdown
!
interface Ethernet0/3
 no ip address
 shutdown
!
interface Ethernet1/0
 no ip address
 shutdown
!
interface Ethernet1/1
 no ip address
 shutdown
!
interface Ethernet1/2
 no ip address
 shutdown
!
interface Ethernet1/3
 no ip address
 shutdown
!         
interface Serial2/0
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/1
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/2
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/3
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/0
 no ip address
 shutdown 
 serial restart-delay 0
!
interface Serial3/1
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/2
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/3
 no ip address
 shutdown
 serial restart-delay 0
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
ip route 0.0.0.0 0.0.0.0 192.168.12.2
ip route 3.3.3.3 255.255.255.255 172.16.13.3
!
ip access-list extended MYGRE
 permit gre any any
ip access-list extended MYTELNET
 permit tcp any any eq telnet
!
!
!
!
control-plane
!
!
!
!
!
!
!
!
line con 0
 logging synchronous
line aux 0
line vty 0 4
 login
 transport input none
!
!
end

R1#

R2#sh run 
Building configuration...

Current configuration : 1778 bytes
!
! Last configuration change at 21:18:16 CET Tue Sep 4 2018
!
version 15.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R2
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
clock timezone CET 1 0
mmi polling-interval 60
no mmi auto-configure
no mmi pvc
mmi snmp-timeout 180
!         
!
!
!
!
!


!
!
!
!
ip cef
no ipv6 cef
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!         
!
redundancy
!
!
! 
!
!
!
!
!
!
!
!
!
!
!
!
interface Ethernet0/0
 ip address 192.168.12.2 255.255.255.0
!
interface Ethernet0/1
 ip address 192.168.23.2 255.255.255.0
!         
interface Ethernet0/2
 no ip address
 shutdown
!
interface Ethernet0/3
 no ip address
 shutdown
!
interface Ethernet1/0
 no ip address
 shutdown
!
interface Ethernet1/1
 no ip address
 shutdown
!
interface Ethernet1/2
 no ip address
 shutdown
!
interface Ethernet1/3
 no ip address
 shutdown 
!
interface Serial2/0
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/1
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/2
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/3
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/0
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/1
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/2
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/3
 no ip address
 shutdown
 serial restart-delay 0
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
ip route 1.1.1.1 255.255.255.255 192.168.12.1
ip route 3.3.3.3 255.255.255.255 192.168.23.3
!
!
!
!
control-plane
!
!
!
!
!
!
!
!
line con 0
 logging synchronous
line aux 0
line vty 0 4
 login
 transport input none
!
!         
end

R2#


R3#sh run 
Building configuration...

Current configuration : 1951 bytes
!
! Last configuration change at 09:38:09 CET Wed Sep 5 2018
!
version 15.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R3
!
boot-start-marker
boot-end-marker
!
aqm-register-fnf
!
!
no aaa new-model
clock timezone CET 1 0
mmi polling-interval 60
no mmi auto-configure
no mmi pvc
mmi snmp-timeout 180
!
!
!
!
!
!


!
!
!
!
ip cef
no ipv6 cef
!
multilink bundle-name authenticated
!
!
!
!
!
!
!         
!
!
redundancy
!
!
! 
!
!
!
!
!
!
!
!
!
!
!
!
interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface Tunnel0
 ip address 172.16.13.3 255.255.255.0
 tunnel source 192.168.23.3
 tunnel destination 192.168.12.1
!
interface Ethernet0/0
 ip address 192.168.23.3 255.255.255.0
!
interface Ethernet0/1
 no ip address
 shutdown
!
interface Ethernet0/2
 no ip address
 shutdown
!
interface Ethernet0/3
 no ip address
 shutdown
!
interface Ethernet1/0
 no ip address
 shutdown
!
interface Ethernet1/1
 no ip address
 shutdown
!
interface Ethernet1/2
 no ip address
 shutdown
!
interface Ethernet1/3
 no ip address
 shutdown
!
interface Serial2/0
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/1
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/2
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/3
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/0
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/1
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/2
 no ip address
 shutdown
 serial restart-delay 0
!         
interface Serial3/3
 no ip address
 shutdown
 serial restart-delay 0
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
ip route 0.0.0.0 0.0.0.0 192.168.23.2
ip route 1.1.1.1 255.255.255.255 172.16.13.1
!
!
!
!
control-plane
!
!
!
!
!
!         
!
!
line con 0
 logging synchronous
line aux 0
line vty 0 4
 login
 transport input telnet
!
!
end

R3# 

now if I run this command on R1:
R1#telnet 3.3.3.3 /source-interface loopback 0

then check policy map this way:



R1#show policy-map interface e0/0
 Ethernet0/0 

  Service-policy output: MYPOLICE

    Class-map: MAPTELNET (match-all)  
      0 packets, 0 bytes
      5 minute offered rate 0000 bps, drop rate 0000 bps
      Match: access-group name MYTELNET
      police:
          cir 128000 bps, bc 4000 bytes
        conformed 0 packets, 0 bytes; actions:
          transmit 
        exceeded 0 packets, 0 bytes; actions:
          drop 
        conformed 0000 bps, exceeded 0000 bps

    Class-map: MAPMYGRE (match-all)  
      11 packets, 893 bytes
      5 minute offered rate 0000 bps
      Match: access-group name MYGRE

    Class-map: class-default (match-any)  
      57 packets, 6335 bytes
      5 minute offered rate 0000 bps, drop rate 0000 bps
      Match: any 
R1#

The class-map used for telnet named MAPTELNET shows 0 packets..

I have read online why this is showing 0 packets, but could not understand the logic they used to explain it..

Any clarification will be very much appreciated

Thank you
ASKER CERTIFIED SOLUTION
Aaron Street
Technical Infrastructure Architecture and Global Network Manager

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