Why does not ICMP Echos come back?

[tomo456]

I tried to construct catalyst2960 on Packet Tracer.

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Switch>ena
Switch#conf t
Switch(config)#ena pass test
Switch(config)#line vty 0 4
Switch(config-line)#pass test2
Switch(config-line)#login
Switch(config-line)#exit
Switch(config)#int vlan 10
Switch(config-if)#ip address 192.168.1.100 255.255.255.0
Switch(config-if)#no shut
Switch(config-if)#exit
Switch(config)#ip default-gateway 192.168.1.1
Switch(config)#int fa0/1
Switch(config-if)#switchport mode access
Switch(config-if)#switchport access vlan 10
Switch(config-if)#no shut
Switch(config-if)#exit
Switch#ping 127.0.0.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 127.0.0.1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
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Why do not Echos come back?

[Seb Rupik]

Hi there,

Whilst on every OS a loopback interface is installed, on a multi-layer switch you need to explicitly configure it. From the output you provide this is not the case.

What is the output of sh ip int br

cheers,

Seb.

[tomo456]

Switch#sh ip int br

Interface IP-Address OK? Method Status Protocol

FastEthernet0/1 unassigned YES manual down down

FastEthernet0/2 unassigned YES manual down down

FastEthernet0/3 unassigned YES manual down down

FastEthernet0/4 unassigned YES manual down down

FastEthernet0/5 unassigned YES manual down down

FastEthernet0/6 unassigned YES manual down down

FastEthernet0/7 unassigned YES manual down down

FastEthernet0/8 unassigned YES manual down down

FastEthernet0/9 unassigned YES manual down down

FastEthernet0/10 unassigned YES manual down down

FastEthernet0/11 unassigned YES manual down down

FastEthernet0/12 unassigned YES manual down down

FastEthernet0/13 unassigned YES manual down down

FastEthernet0/14 unassigned YES manual down down

FastEthernet0/15 unassigned YES manual down down

FastEthernet0/16 unassigned YES manual down down

FastEthernet0/17 unassigned YES manual down down

FastEthernet0/18 unassigned YES manual down down

FastEthernet0/19 unassigned YES manual down down

FastEthernet0/20 unassigned YES manual down down

FastEthernet0/21 unassigned YES manual down down

FastEthernet0/22 unassigned YES manual down down

FastEthernet0/23 unassigned YES manual down down

FastEthernet0/24 unassigned YES manual down down

GigabitEthernet0/1 unassigned YES manual down down

GigabitEthernet0/2 unassigned YES manual down down

Vlan1 unassigned YES manual administratively down down

Vlan10 192.168.1.100 YES manual up down

Switch#

[Seb Rupik]

Thanks for sharing the output.

As I suspected you have not explicitly configured a loopback interface with the address 127.0.0.1, and IOS does not configure one by default like a computer Operating System does. On this basis a ping to 127.0.0.1 will always fail.

cheers,

Seb.

[tomo456]

Catalyst 2960 can not configure "Loopback."

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Switch#ping 127.0.0.1

Switch#interface Loopback0
^
% Invalid input detected at '^' marker.

Switch#conf t
Switch(config)#interface ?
Ethernet IEEE 802.3
FastEthernet FastEthernet IEEE 802.3
GigabitEthernet GigabitEthernet IEEE 802.3z
Port-channel Ethernet Channel of interfaces
Vlan Catalyst Vlans
range interface range command

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[rjds]

Hi Tomo456
You can only configure Loopback in a Multilayer Switch.!!