Configuring Layer3 etherchannel

Continuing from previous configuration layer3 etherchannel will be configured on 3550-1.

First unsubscribe all etherchannel ports from group 1, if you do not do this switchport will not be able to turn off.

3550-1(config-if-range)#no channel-group 1
3550-1(config-if-range)#
*Mar 1 01:26:52.947: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel1, changed state to down
3550-1(config-if-range)#
*Mar 1 01:26:53.963: %LINK-3-UPDOWN: Interface Port-channel1, changed state to down

Switchport has to be turned off to use the feature of a router.

Let’s observed the difference before turning off switchport and after turning off:

Before switchport is turned off:

3550-1(config-if-range)#ip ?
Interface IP configuration subcommands:
access-group Specify access control for packets
admission Apply Network Admission Control
arp Configure ARP features
dhcp Configure DHCP parameters for this interface
igmp IGMP interface commands
verify verify
vrf VPN Routing/Forwarding parameters on the interface

After switchport is off:

3550-1(config-if-range)#no switchport
3550-1(config-if-range)#ip ?
Interface IP configuration subcommands:
access-group Specify access control for packets
accounting Enable IP accounting on this interface
address Set the IP address of an interface
admission Apply Network Admission Control
arp Configure ARP features
authentication authentication subcommands
bandwidth-percent Set EIGRP bandwidth limit
bgp BGP interface commands
broadcast-address Set the broadcast address of an interface
cef Cisco Express Forwarding interface commands
cgmp Enable/disable CGMP
dhcp Configure DHCP parameters for this interface
directed-broadcast Enable forwarding of directed broadcasts
dvmrp DVMRP interface commands
hello-interval Configures EIGRP-IPv4 hello interval
helper-address Specify a destination address for UDP broadcasts
hold-time Configures EIGRP-IPv4 hold time
igmp IGMP interface commands
information-reply Enable sending ICMP Information Reply messages
irdp ICMP Router Discovery Protocol
load-sharing Style of load sharing
–More–

There are still a lot of commands available…I do not want to flood my notes with all available commands for router.

Assign ip address to 3550-1, now 3550-1 is a router.

3550-1(config-if-range)#ip address 10.1.1.1 255.255.255.0
10.1.1.0 overlaps with FastEthernet0/1
% Interface range command failed for FastEthernet0/3
10.1.1.0 overlaps with FastEthernet0/1
% Interface range command failed for FastEthernet0/5

Oops, I forgot fa0/1, fa0/3, fa0/5 have already unsubscribed from etherchannel.

3550-1(config-if-range)#channel-group 1 mode active
Command rejected (Port-channel1, Fa0/1): Either port is L2 and port-channel is L3, or vice-versa

% Range command terminated because it failed on FastEthernet0/1

Nope I cannot do this either…

3550-1(config)#int po1
3550-1(config-if)#no switchport
3550-1(config-if)#ip address 10.1.1.1 255.255.255.0

port-channel 1 is like one link to MLS, I still need to turn off the switchport at port channel 1.
3550-1(config-if)#do sh ip int brief
Interface IP-Address OK? Method Status Protocol
<truncated>
Port-channel1 10.1.1.1 YES manual down down

It’s down because of this:

3550-1(config-if)#do sh ether summ
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(RD) –

No members in port-channel 1

3550-1(config)#int range fa0/1, fa0/3, fa0/5
3550-1(config-if-range)#channel-group 1 mode active
3550-1(config-if-range)#

3550-1(config-if-range)#do sh ether summ
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(RU) LACP Fa0/1(P) Fa0/3(P) Fa0/5(P)

Great! It’s working. Now port channel 1 is like a router’s port connecting to a switch port (2950-1)

3550-1(config-if-range)#do sh ip int brief
Interface IP-Address OK? Method Status Protocol
<truncated>
Port-channel1 10.1.1.1 YES manual up up

Great! It’s up now, so it’s working for sure!

3550-1#copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
3550-1#

3550-1#sh spanning-tree vlan 1

Spanning tree instance(s) for vlan 1 does not exist.

port-channel 1 is no more a switchport so no spanning tree is needed.

2950-1#sh ip int brief
Interface IP-Address OK? Method Status Protocol
<truncated>
Port-channel1 unassigned YES unset up up
2950-1#

2950-1#sh ether summ
Flags: D – down P – in port-channel
I – stand-alone s – suspended
H – Hot-standby (LACP only)
R – Layer3 S – Layer2
u – unsuitable for bundling
U – in use f – failed to allocate aggregator
d – default port

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

Group Port-channel Protocol Ports
——+————-+———–+———————————————–
1 Po1(SU) LACP Fa0/1(Pd) Fa0/2(P) Fa0/3(P)

2950-1#copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
2950-1#

2950-1#sh spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 32769
Address 000d.2944.c200
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 000d.2944.c200
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300

Interface Role Sts Cost Prio.Nbr Type
—————- —- — ——— ——– ——————————–
Po1 Desg FWD 9 128.65 P2p

Cost value is 9, which is 300mbps throughput.
All working, I can connect my laptop to 2950-1 😉