Problems with etherchannel between 2970 and 3500xl

[btenney]

3500xl :

Version 12.0(5)WC10

2970:

Version 12.1(11)AX

I have four physical ports setup in group 1.

2970 CONFIG:

interface GigabitEthernet0/21-24

switchport mode access

no ip address

duplex full

speed 100

channel-group 1 mode on

3500XL CONFIG:

interface FastEthernet0/45-48

duplex full

speed 100

port group 1

ETHERCHANNEL SUMMARY 2970

sh etherchannel summary

Flags: D - down P - in port-channel

I - stand-alone s - suspended

R - Layer3 S - Layer2

u - unsuitable for bundling

U - port-channel in use

Group Port-channel Ports

-----+------------+-----------------------------------------------------------

1 Po1(SU) Gi0/21(P) Gi0/22(P) Gi0/23(P) Gi0/24(P)

ETHERCHANNEL SUMMARY FOR 3500XL

Flags: d - default D - down

I - in use

Group Ports

----- -----

1 Fa0/46(D) Fa0/45(Dd) Fa0/48(D) Fa0/47(D)

Everything seems to be working with 2970 and data is definitly going through. I am telneting through connection and servers are plugged in.

3500xl shows interfaces being down and spanning tree in block state. I know the etherchannel is working but the 3500 says everything is down. Any help would be appreciated.

Thanks,

Brett

[Georg Pauwen]

Hello Brett,

your 2950 has the channel mode set to on, which means it only builds the channel when the other side is explicitly configured for it. Try and add the command:

switchport mode trunk

to the interface range on your 3500XL switch.

HTH,

Georg

[btenney]

Tried adding that command to the 3500xl interfaces and it did not make a difference. Since 2970 is set to mode access, I also tried changing mode to trunk on that. No difference. I just moved both switches back to mode access for now.

Everything is on vlan1. spanning tree shows forwarding on 2970 and blocked on 3500xl. interfaces w/port group see traffic on 2970 but none on 3500 which seems impossible since that is the only route I can take to telnet into 2970. All interfaces on 3500xl say down when the lights are green on all four interfaces. The green lights are blinking as well.

[scottmac]

Check to see the the Native VLAN is set the same on both sides. It defaults to VLAN 1, but perhaps it was changed sometime in the past.

Good Luck

Scott

[btenney]

Thanks.

I double checked and they are both on vlan1. No trunking is required. 2970 says port-channel is up and up with span tree fwd. 3500xl is still saying everything is down even with green lights blinking and data going through. Even span tree says blk state.

Sh cdp neigh from 2970 sees 3500. output on 3500 doesnt see the 2970. Wierd.

Thanks,

Brett

[aashish.c]

Hi Brett,

Please send me the sh run configuration of both switches.

On 3500xl, I would like to confirm whether all the links are coming as BLK by STP or 1 of them is FWD. Kindly send me the sh span tree output for all the ports . 3500xl doesn`t do any negotiation for FEC.

I doubt that there is no FEC running, but the data is going through a normal link . Just to clear the functionality kindly remove any random link and check whether it shifts the load to other link or not.

also send me these from 2970 :

show etherchannel 1 detail

show etherchannel 1 port

show etherchannel 1 port-channel

Thanks

aashish C

[btenney]

2950 (show run)

Current configuration : 1965 bytes

!

version 12.1

spanning-tree mode pvst

spanning-tree extend system-id

!

!

interface Port-channel1

switchport mode access

no ip address

!

interface GigabitEthernet0/1

no ip address

!

interface GigabitEthernet0/2

no ip address

!

interface GigabitEthernet0/3

no ip address

!

interface GigabitEthernet0/4

no ip address

!

interface GigabitEthernet0/5

no ip address

!

interface GigabitEthernet0/6

no ip address

!

interface GigabitEthernet0/7

no ip address

!

interface GigabitEthernet0/8

no ip address

!

interface GigabitEthernet0/9

no ip address

!

interface GigabitEthernet0/10

no ip address

!

interface GigabitEthernet0/11

no ip address

!

interface GigabitEthernet0/12

no ip address

!

interface GigabitEthernet0/13

no ip address

!

interface GigabitEthernet0/14

no ip address

!

interface GigabitEthernet0/15

no ip address

!

interface GigabitEthernet0/16

no ip address

!

interface GigabitEthernet0/17

no ip address

!

interface GigabitEthernet0/18

no ip address

!

interface GigabitEthernet0/19

no ip address

!

interface GigabitEthernet0/20

no ip address

!

interface GigabitEthernet0/21

no switchport mode access

no ip address

duplex full

speed 100

no channel-group 1 mode on

!

interface GigabitEthernet0/22

no switchport mode access

no ip address

duplex full

speed 100

no channel-group 1 mode on

!

interface GigabitEthernet0/23

no switchport mode access

no ip address

duplex full

speed 100

no channel-group 1 mode on

!

interface GigabitEthernet0/24

no switchport mode access

no ip address

duplex full

speed 100

no channel-group 1 mode on

!

interface Vlan1

ip address 10.x.x.x 255.255.255.0

no ip route-cache

!

end

3500xl (show run)

Building configuration...

Current configuration:

!

version 12.0

no service pad

ip subnet-zero

cluster enable SLC_Cat_Cluster 0

cluster member 1 mac-address 0007.850a.6a00

cluster member 2 mac-address 0007.853e.2c80

interface FastEthernet0/1

!

interface FastEthernet0/2

!

interface FastEthernet0/3

duplex full

speed 100

!

interface FastEthernet0/4

!

interface FastEthernet0/5-42

!

interface FastEthernet0/43

!

interface FastEthernet0/44

!

interface FastEthernet0/45

duplex full

speed 100

port group 1

!

interface FastEthernet0/46

duplex full

speed 100

port group 1

!

interface FastEthernet0/47

duplex full

speed 100

port group 1

!

interface FastEthernet0/48

duplex full

speed 100

port group 1

!

interface GigabitEthernet0/1

!

interface GigabitEthernet0/2

!

interface VLAN1

ip address 10.x.x.x 255.255.192.0

no ip directed-broadcast

ip nat outside

!

ip default-gateway 10.x.x.x

ip nat inside source list 199 interface VLAN1 overload

access-list 199 dynamic Cluster-NAT permit ip any any

snmp-server engineID local 0000000902000007853E0840

snmp-server community convict@es0 RO

snmp-server community convict RO

snmp-server community guard RW

snmp-server community guard@es0 RW

[btenney]

sh etherchannel 1 detail

Group state = L2

Ports: 4 Maxports = 8

Port-channels: 1 Max Port-channels = 1

Ports in the group:

-------------------

Port: Gi0/21

------------

Port state = Up Mstr In-Bndl

Channel group = 1 Mode = On/FEC Gcchange = 0

Port-channel = Po1 GC = 0x00010001 Pseudo port-channel = Po1

Port index = 0 Load = 0x00

Age of the port in the current state: 00d:00h:01m:13s

Port: Gi0/22

------------

Port state = Up Mstr In-Bndl

Channel group = 1 Mode = On/FEC Gcchange = 0

Port-channel = Po1 GC = 0x00010001 Pseudo port-channel = Po1

Port index = 0 Load = 0x00

Age of the port in the current state: 00d:00h:01m:13s

Port: Gi0/23

------------

Port state = Up Mstr In-Bndl

Channel group = 1 Mode = On/FEC Gcchange = 0

Port-channel = Po1 GC = 0x00010001 Pseudo port-channel = Po1

Port index = 0 Load = 0x00

Age of the port in the current state: 00d:00h:01m:13s

Port: Gi0/24

------------

Port state = Up Mstr In-Bndl

Channel group = 1 Mode = On/FEC Gcchange = 0

Port-channel = Po1 GC = 0x00010001 Pseudo port-channel = Po1

Port index = 0 Load = 0x00

Age of the port in the current state: 00d:00h:01m:13s

Port-channels in the group:

----------------------

Port-channel: Po1

------------

Age of the Port-channel = 00d:00h:01m:17s

Logical slot/port = 10/1 Number of ports = 4

GC = 0x00010001 HotStandBy port = null

Port state = Port-channel Ag-Inuse

Ports in the Port-channel:

Index Load Port EC state

------+------+------+------------

0 00 Gi0/21 on

0 00 Gi0/22 on

0 00 Gi0/23 on

0 00 Gi0/24 on

Time since last port bundled: 00d:00h:01m:13s Gi0/24

-------------------------------

sh etherchannel 1 port

Ports in the group:

-------------------

Port: Gi0/21

------------

Port state = Up Mstr In-Bndl

Channel group = 1 Mode = On/FEC Gcchange = 0

Port-channel = Po1 GC = 0x00010001 Pseudo port-channel = Po1

Port index = 0 Load = 0x00

Age of the port in the current state: 00d:00h:01m:38s

Port: Gi0/22

------------

Port state = Up Mstr In-Bndl

Channel group = 1 Mode = On/FEC Gcchange = 0

Port-channel = Po1 GC = 0x00010001 Pseudo port-channel = Po1

Port index = 0 Load = 0x00

Age of the port in the current state: 00d:00h:01m:38s

Port: Gi0/23

------------

Port state = Up Mstr In-Bndl

Channel group = 1 Mode = On/FEC Gcchange = 0

Port-channel = Po1 GC = 0x00010001 Pseudo port-channel = Po1

Port index = 0 Load = 0x00

Age of the port in the current state: 00d:00h:01m:38s

Port: Gi0/24

------------

Port state = Up Mstr In-Bndl

Channel group = 1 Mode = On/FEC Gcchange = 0

Port-channel = Po1 GC = 0x00010001 Pseudo port-channel = Po1

Port index = 0 Load = 0x00

Age of the port in the current state: 00d:00h:01m:38s

--------------------------

sh etherchannel 1 port-channel

Port-channels in the group:

----------------------

Port-channel: Po1

------------

Age of the Port-channel = 00d:00h:03m:11s

Logical slot/port = 10/1 Number of ports = 4

GC = 0x00010001 HotStandBy port = null

Port state = Port-channel Ag-Inuse

Ports in the Port-channel:

Index Load Port EC state

------+------+------+------------

0 00 Gi0/21 on

0 00 Gi0/22 on

0 00 Gi0/23 on

0 00 Gi0/24 on

Time since last port bundled: 00d:00h:03m:06s Gi0/24

[btenney]

I took the etherchannel down so thats why its only been up for 3 min. Transfers were going very slow. I had the same problem with just 1 crossover and no etherchannel config. Link was showing down on 3500 with just crossover. Wondering if the clustering is causing problems. Not really sure what is going on.

[btenney]

UPDATE: 8/17/04

I took out all fast ethernet configs. I am only using a crossover with hard set speed. The int is still showing down and spanning tree blocked on the port 48 on 3500xl. The light is blinking green and data is going across since I am able to telnet.

[aashish.c · Accepted solution]

Hi,

As you have connected just 1 port so have u erased the port-group config from port 48 on 3500xl. if u did so and still shpwing down, then I would suggest you to shut doen the port manually and do a no shut.

also try changing the ports on 350xl.

Thanks

aashish C