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Switch to Router Etherchannel; MACFLAP error message

Johnny Segway
Level 1
Level 1

Hi - I'm just labbing for ICND2 and wanted to connect a Router to Switch etherchannel through 2 ports on each device, but now having recurring error message:

 

*Mar  1 02:05:11.452: %SW_MATM-4-MACFLAP_NOTIF: Host XXXX.XXXX.XXXX in vlan 1 is flapping between port Fa0/1 and port Fa0/2
*Mar  1 02:12:03.987: %SW_MATM-4-MACFLAP_NOTIF: Host XXXX.XXXX.XXXX in vlan 1 is flapping between port Fa0/2 and port Fa0/1

 

So I have Router: G0/0 connected to Switch: F0/1 and G0/1 connected to Switch F0/2.

 

The Router has aggregated its two ports into 1 channel (so I think that end is configured correctly); but the Switch doesn't look too healthy as port channel is in shutdown. Any idea where I have gone wrong please?

 

Switch#sh etherchannel summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port


Number of channel-groups in use: 1
Number of aggregators:           1

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
1      Po1(SD)         LACP      Fa0/1(I)    Fa0/2(I) 

 the config for the Switch below:

 

Switch#sh run
Building configuration...

Current configuration : 1375 bytes
!
version 12.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Switch
!
boot-start-marker
boot-end-marker
!
!
!
!
no aaa new-model
system mtu routing 1500
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
vlan internal allocation policy ascending
!
!
interface Port-channel1
!
interface FastEthernet0/1
 channel-group 1 mode active
!
interface FastEthernet0/2
 channel-group 1 mode active
!
interface FastEthernet0/3
!
interface FastEthernet0/4
!
interface FastEthernet0/5
!
< --- SNIP! ----> ! interface FastEthernet0/23 ! interface FastEthernet0/24 ! interface Vlan1  ip address 192.168.1.254 255.255.255.0  no ip route-cache ! ip default-gateway 192.168.1.1 ip http server ip http secure-server !          line con 0  exec-timeout 0 0  logging synchronous line vty 0 4  login line vty 5 15  login ! end

 

The config for the Router:

 

Router#sh run
Building configuration...

Current configuration : 970 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
!
ip cef
!
voice-card 0
 no dspfarm
!         
interface Loopback0
 ip address 10.0.0.1 255.255.255.0
!
interface Port-channel10
 ip address 192.168.1.1 255.255.255.0
 hold-queue 150 in
!
interface FastEthernet0/0
 no ip address
 duplex auto
 speed auto
 channel-group 10
!
interface FastEthernet0/1
 no ip address
 duplex auto
 speed auto
 channel-group 10
!
interface Serial0/2/0
 no ip address
 shutdown
 no fair-queue
 clock rate 2000000
!
interface Serial0/3/0
 no ip address
 shutdown 
 clock rate 2000000
!
ip forward-protocol nd
!
!
ip http server
no ip http secure-server
!
control-plane
!
!
!
line con 0
 exec-timeout 0 0
 logging synchronous
line aux 0
line vty 0 4
 login
!
scheduler allocate 20000 1000
!
end
1 Reply 1

Make sure that both ends of the channel use LACP or both ends are configured statically (mode on).

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