ā04-16-2012 04:16 AM - edited ā03-07-2019 06:09 AM
I'm using Packet Tracer for testing since I don't have the actual equipment. I have configured etherchannel between two 2960 Switches. I have used the trunk ports FE 0/23 and FE 0/24 on both switches to create the etherchanel. I have connected one PC with each switch. The PCs are in the same VLAN and can ping each other. Howver, when I take down one of the links in the etherchannel, the other link does not take over and I get 100% packet loss. I don't know what seems to be the problem. I'm quoting the configurations below:
Switch0:
Switch#sh running-config
Building configuration...
Current configuration : 1179 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Switch
!
!
spanning-tree mode pvst
!
!
! OUTPUT TRUNCATED !
!
!
interface FastEthernet0/23
channel-group 5 mode on
switchport mode trunk
!
interface FastEthernet0/24
channel-group 5 mode on
switchport mode trunk
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Port-channel 5
switchport mode trunk
!
interface Vlan1
no ip address
shutdown
!
!
! OUTPUT TRUNCATED !
!
!
end
Switch#show interfaces trunk
Port Mode Encapsulation Status Native vlan
Fa0/23 on 802.1q trunking 1
Fa0/24 on 802.1q trunking 1
Po5 on 802.1q trunking 1
Port Vlans allowed on trunk
Fa0/23 1-1005
Fa0/24 1-1005
Po5 1-1005
Port Vlans allowed and active in management domain
Fa0/23 1
Fa0/24 1
Po5 1
Port Vlans in spanning tree forwarding state and not pruned
Fa0/23 1
Fa0/24 1
Po5 1
Switch#show etherchannel summary
Number of channel-groups in use: 1
Number of aggregators: 1
Group Port-channel Protocol Ports
------+-------------+-----------+----------------------------------------------
5 Po5(SU) - Fa0/23(P) Fa0/24(P)
Switch 1:
Switch#sh running-config
Building configuration...
Current configuration : 1179 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Switch
!
!
spanning-tree mode pvst
!
!
! OUTPUT TRUNCATED !
!
interface FastEthernet0/23
channel-group 5 mode on
switchport mode trunk
!
interface FastEthernet0/24
channel-group 5 mode on
switchport mode trunk
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Port-channel 5
switchport mode trunk
!
interface Vlan1
no ip address
shutdown
!
! OUTPUT TRUNCATED !
!
!
end
Switch#show interfaces trunk
Port Mode Encapsulation Status Native vlan
Fa0/23 on 802.1q trunking 1
Fa0/24 on 802.1q trunking 1
Po5 on 802.1q trunking 1
Port Vlans allowed on trunk
Fa0/23 1-1005
Fa0/24 1-1005
Po5 1-1005
Port Vlans allowed and active in management domain
Fa0/23 1
Fa0/24 1
Po5 1
Port Vlans in spanning tree forwarding state and not pruned
Fa0/23 1
Fa0/24 1
Po5 1
Switch#show etherchannel summary
Number of channel-groups in use: 1
Number of aggregators: 1
Group Port-channel Protocol Ports
------+-------------+-----------+----------------------------------------------
5 Po5(SU) - Fa0/23(P) Fa0/24(P)
ā04-16-2012 04:17 AM
I don't know why isn't it working..
ā04-16-2012 04:21 AM
If the channel shows up with only 1 port being int he channel when you shut 1 port down then it's probably a packet tracer issue. You can't rely on everything you see in some of these emulator programs. I ahve never used PT but if you can check and see where it knows the mac address of the other pc then maybe you can troubleshoot . Does it still know the mac of the other pc across that etherchannel.
ā07-14-2012 09:26 PM
It was a packet tracer issue. I have tried etherchannel with actual cisco 2960 switches and it is working. This thread may be closed.
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