Creating Ether-channel between Cisco 2960-X Switches

Mohammed Ismail Shareef · ‎08-04-2015

Hi All,

I am trying to configure Ether-Channel between my two 2960-X switches but i am failing at doing so. Could anyone help understand and configure it properly. Below is my setup and requirement.

SW01:

Gig 1/0/23 & Gig 1//0/24 are connected to Cisco ASA Firewall and are configured as etherchannel.

interface Port-channel1

switchport mode trunk

!

interface GigabitEthernet 1/0/23

swtichport mode trunk

channel-group 1 mode on

!

interface GigabitEthernet 1/0/24

swtichport mode trunk

channel-group 1 mode on

There are VLANs (10,20,30,40) configured on SW01 too as i have multiple sub-interfaces on Cisco ASA.

I have a new SW02 where i am connecting more devices so i pulled two cables from SW01 to SW02 and did the below configuration.

SW01:

interface Port-channel2

switchport mode trunk

!

interface GigabitEthernet 1/0/21

swtichport mode trunk

channel-group 2 mode on

!

interface GigabitEthernet 1/0/22

swtichport mode trunk

channel-group 2 mode on

SW02:

interface Port-channel2

switchport mode trunk

!

interface GigabitEthernet 1/0/23

swtichport mode trunk

channel-group 2 mode on

!

interface GigabitEthernet 1/0/24

swtichport mode trunk

channel-group 2 mode on

However i created VLANs 10,20,30,40 but i have no communication between them.

Kindly suggest.

Regards

@Mohammed

Mark Malone · ‎08-04-2015

Is the etherchannel up ? can you post show etherchannel summ

Mohammed Ismail Shareef · ‎08-04-2015

Hi Mark,

Below is the appropriate output;

SW01#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: 2
Number of aggregators: 2

Group Port-channel Protocol Ports
------+-------------+-----------+-----------------------------------------------
1 Po1(SU) - Gi1/0/23(P) Gi1/0/24(P)
2 Po2(SD) - Gi1/0/6(D) Gi1/0/8(D)

Port 23 & 24 = ASA

Port 6 & 8 = SW02

SW02#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
------+-------------+-----------+-----------------------------------------------
2 Po2(SD) - Gi1/0/1(D) Gi1/0/2(D)

Mark Malone · ‎08-04-2015

Hi the port-channel between the 2 2960s is po2 correct? No port-channel to the ASA on switch 2 yes as only 1 showing setup po2 ,po2 it's currently switched down state can you post the current config of there member ports 6,8,1 & 2, , is that the way you have it cabled those 4 ports connected directly between switches

Mohammed Ismail Shareef · ‎08-04-2015

Hi Mark,

Yes the port-channel between the switches is po2.

No port-channel to the ASA on SW2 its only on SW01 (po1).

SW01:

!
interface Port-channel1
switchport mode trunk
!
interface Port-channel2
switchport mode trunk

interface GigabitEthernet1/0/6
switchport mode trunk
channel-group 2 mode on
!
interface GigabitEthernet1/0/8
switchport mode trunk
channel-group 2 mode on
!

interface GigabitEthernet1/0/23
switchport mode trunk
channel-group 1 mode on
!
interface GigabitEthernet1/0/24
switchport mode trunk
channel-group 1 mode on
!

SW02:

interface Port-channel2
switchport mode trunk
!
interface GigabitEthernet1/0/1
switchport mode trunk
channel-group 2 mode on
!
interface GigabitEthernet1/0/2
switchport mode trunk
channel-group 2 mode on

Yes cables are connected between SW01 P6&P8 - SW02 P1&P2

Regards

@Mohammed

InayathUlla Sharieff · ‎08-04-2015

Hi,

I see the PO to be down:-

Group Port-channel Protocol Ports
------+-------------+-----------+-----------------------------------------------
2 Po2(SD) - Gi1/0/1(D) Gi1/0/2(D) >> donw sate.

So could we try the following:-

1- Remove the port-channel config from the ports and see if the links are coming back online?

2- Then once you confirmed that then shut down the ports at both the ends.

3- Configure the port-channel configuration and then applied the PO channel command for the physical interface.

4- Bring the physical interface both the ends.

5- Try not using the on mode.

HTH

Regards

Inayath

Mohammed Ismail Shareef · ‎08-05-2015

Hi,

Regardless to what you mentioned above i did "shut & no shut" on both the interfaces and got the below error;

Aug 5 08:14:27.037: %PM-4-ERR_DISABLE: channel-misconfig (STP) error detected on Gi1/0/8, putting Gi1/0/8 in err-disable state
Aug 5 08:14:27.075: %PM-4-ERR_DISABLE: channel-misconfig (STP) error detected on Gi1/0/6, putting Gi1/0/6 in err-disable state

Could you also clarify on the above your points as i didn't understood.

Regards

@Mohammed

Mark Malone · ‎08-05-2015

Are you using the range command to do this? bringing up 1 interface at a time can cause stp issues

Have you changed it to lacp or pagp instead of on mode

did you allow the switch to create to create the port-channel interface? do not create it yourself it automatically creates when you use the channel-group command

remove the config completely port-channel and default the interfaces then apply this

interface range g1/0/1 - 2
switchport trunk encapsulation dot1q
switchport mode trunk
switchport nonegotiate
channel-group 2 mode desirable
shutdown

interface range g1/0/6 - 7
switchport trunk encapsulation dot1q
switchport mode trunk
switchport nonegotiate
channel-group 2 mode active
shutdown

Then when the po is created each side and everything is configured bring them up together

interface range g1/0/1 - 2
no shut

interface range g1/0/6 - 7
no shut

Mark Malone · ‎08-05-2015

Any luck doing it by range command ?

Mohammed Ismail Shareef · ‎08-06-2015

Hi Mark,

i did not do any other fresh config but just by doing "shut and no shut" on interface port-channel2 all started working fine.

Thanks for your inputs and great efforts.

Regards

@Mohammed

Mark Malone · ‎08-06-2015

No problem glad you got it sorted

Mark Malone · ‎08-05-2015

Ye i agree with InayathUlla below i would shut it down reapply it and use LACP , sometimes using on mode if not brought up correctly can cause issues like stp problems

For LACP thats all you need to change passive 1 side active on the other , keep the passive side shut down until your ready

channel-group 2 mode active

channel-group 2 mode passive