check the etherchannel status
S4#show 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
Number of channel-groups in use: 1
Number of aggregators: 1
Group Port-channel Protocol Ports
——+————-+———–+———————————————–
1 Po1(RU) – Gi2/6(P) Gi2/10(P)
see.. RU . it’s a layer 3 port
by default, if you start the machine and you see the name is router> then, all ports are layer 3 port
if switch> then all ports are on switchport mode
just change to layer2 are switchport to solve this
>switchport on both Gi2/6, Gi2/10
>switchport on po 1
show etherchannel again
SW1#show eth sum
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
Number of channel-groups in use: 1
Number of aggregators: 1
Group Port-channel Protocol Ports
——+————-+———–+———————————————–
1 Po1(SU) – Gi2/6(P) Gi2/10(P)
now SU already… happy trunking !!