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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:
now if I run this command on R1:
R1#telnet 3.3.3.3 /source-interface loopback 0
then check policy map this way:
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
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
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