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Hello everyone,

I'm having some issues with EtherChannel between a Cisco 3550 and a Sun
system with a quad port network card (a GigaSwift card) running
Trunking 1.3.

On the switch, I setup the ports as follows:
------------------------------------------------------------
configure terminal
interface range fa0/11 - 14
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 2 mode auto
no spanning-tree vlan 1
end
------------------------------------------------------------

This seems to work, however, on the Sun systems I'm getting an error
indicating that other systems have my MAC Address. I've gone over my
Trunking configuration with Sun, and they feel I have an issue on my
switch. Now, I'm a noob with Cisco IOS, so that's not totally out of
the realm of the possible.

I used a Cisco guide on setting up Layer-2 EtherChannel and did not
have any considerable issues, but since it isn't working quite right, I
must have done something wrong.

Any advice would be greatly appreciated.

Steven

Note, as I said, I'm a noice with IOS, so if you need additional
information, please provide the command I should run (I'm learning as I
go). Thanks.

Output of 'show etherchannel':
------------------------------------------------------------
Cat3550cape>show etherchannel
Channel-group listing:
-----------------------

Group: 1
----------
Group state = L2
Ports: 4 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: PAgP

Group: 2
----------
Group state = L2
Ports: 4 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: PAgP
------------------------------------------------------------
(Yes, there are 2 channels as there are 2 servers configured the same
way having the same error)


Output (truncated) of 'show running-config':
------------------------------------------------------------
....
interface Port-channel1
switchport mode dynamic desirable
!
interface Port-channel2
switchport mode dynamic desirable
!
interface FastEthernet0/1
switchport trunk encapsulation dot1q
switchport mode trunk
duplex full
channel-group 1 mode auto
!
interface FastEthernet0/2
switchport trunk encapsulation dot1q
switchport mode trunk
duplex full
channel-group 1 mode auto
!
interface FastEthernet0/3
switchport trunk encapsulation dot1q
switchport mode trunk
duplex full
channel-group 1 mode auto
!
interface FastEthernet0/4
switchport trunk encapsulation dot1q
switchport mode trunk
duplex full
channel-group 1 mode auto
....
------------------------------------------------------------

I'm having some issues with EtherChannel between a Cisco 3550 and a Sun
system with a quad port network card (a GigaSwift card) running
Trunking 1.3.

On the switch, I setup the ports as follows:
------------------------------------------------------------
configure terminal
interface range fa0/11 - 14
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 2 mode auto
no spanning-tree vlan 1
end
------------------------------------------------------------

This seems to work, however, on the Sun systems I'm getting an error
indicating that other systems have my MAC Address. I've gone over my
Trunking configuration with Sun,

The Sun message "other systems have my
MAC Address" could result from packets sent
from the sun being returned to it. This would happen
quite correctly if the channel was not up and
broadcast traffic was sent by the sun.
Maybe the channels are not always up correctly?

You may be confsing EtherChannel with dot1q
trunking.

They are completely different concepts.

In any case the trunking commands are applied
to the individual interface and not to the channel.

1.
Take out the trunk commands.

2.
Read about PaGP, figure out if the sun wants
to (or indeed can) negotiate EtherChannel.

You could try setting the switch EtherChannel to ON.

It's been a while since I did this so I can't help in detail
right now.

Also worthwhile might be a debug of PaGP
if that is available.

Finally, the issue might just be a few leaked frames.
Maybe they don't really matter.

Can you look with tcpdump which I think tells you
IIRC whether frames have been sent or received on
an interface?

It's quite possible I'm confusing something. The docs and newsgroups I
read indicated that EtherChannel was what I was looking to do, so
that's the direction I went in. I'll do some additional reading.

Using the Sun Trunking software, I can see exactly what interfaces are
getting packets, and it works as expected (other than the errors I'm
getting).

Thanks for the response, I'll have to read a bit more.

Some of the confusion may be arising from
different terminology being used by various
manufacturers.

http://www.sun.com/products/networking/ ... ntrunking/
"Sun Trunking 1.3 software allows you to aggregate up to sixteen
Sun GigabitEthernet adapter card ports or up to sixteen 10/100
Sun FastEthernet adapter card ports into a single virtual link or
trunk."

Cisco call this an EtherChannel. What cisco call a Trunk
is completely different. 802.1q is the current trunk technology.

Originally Cisco used their own proprietary protocol
to negotiate and manage EtherChannel. PAgP or
Port Aggregation Protocol. There is now an
IEEE standard for Link Aggregation (802.3ad) which used
Link Aggerrgation Control Protocol.

Cisco seem to me to have deliberately blurred the difference
in their docs. For example they are both referred to as
EtherChannel.

So, you want to use 802.3ad and LACP.
I would remove the "Trunking commands" just to tidy up.


configure terminal
interface range fa0/11 - 14
no switchport trunk encapsulation dot1q
switchport mode access
switchport mode access vlan xxx ! <-- set your vlan if not defalt
(Vlan1)
end


# # # # # #

Group: 1
----------
Group state = L2
Ports: 4 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: PAgP <------ sun does only static 802.3ad

http://www.cisco.com/en/US/products/hw/ ... html#25587

configure terminal
interface range fa0/11 - 14
channel-group x mode on ! <----- Cisco-on = Sun-static
end

In general it is not recommended to use "on" since
this can cause problems in the event of a failure
of some of the links.


At the end of the day though, if these mesages are recurring and
if the links are not going up and down, it does point to
a loop of some sort in the network.

If the leakage rate of low it may well not make any difference,
turn of the mesages.

If you can open a TAC case. If you can't,

Hi,

I now believe that the Cisco was not in fact aggregating
the links at all. The combination of the configured mode
(auto) and the lack of PAgP would result in the cisco
not bringing up the channel.

Configure as described in the last mail.

Here is one of mine.

sh etherch

displays the configured channel state.


! sh eth det ! - is similar
switch2#sh int eth
----
GigabitEthernet8/20:
Port state = Up Mstr In-Bndl
Channel group = 1 Mode = On/FEC Gcchange = -
Port-channel = Po1 GC = - Pseudo port-channel
= Po1
Port index = 0 Load = 0x00 Protocol = -

Age of the port in the current state: 49d:17h:02m:47s

----
GigabitEthernet8/21:
Port state = Up Mstr In-Bndl
Channel group = 1 Mode = On/FEC Gcchange = -
Port-channel = Po1 GC = - Pseudo port-channel
= Po1
Port index = 1 Load = 0x00 Protocol = -

Age of the port in the current state: 49d:17h:02m:47s

----
Port-channel1:
Age of the Port-channel = 49d:17h:02m:47s
Logical slot/port = 11/1 Number of ports = 2
GC = 0x00000000
Port state = Port-channel Ag-Inuse
Protocol = -

Ports in the Port-channel:

Index Load Port EC state No of bits
------+------+------+------------------+-----------
0 00 Gi8/20 On/FEC 0
1 00 Gi8/21 On/FEC 0

Time since last port bundled: 49d:17h:02m:47s Gi8/23
Time since last port Un-bundled: 49d:17h:02m:47s Gi1/2

It won't matter _AT ALL_ if one end "thinks" Cisco proprietary
EtherChannel and the other end "thinks" 802.3ad.
All they each care about is that they load balance frames
outbound.

IIRC Suns by default use the SAME MAC address on all ports.
You need to make sure that you change this OR
do load balancing on some source address parameters
on the cisco.

Or get a better switch that does load balancing on
IP addess/ports/whatever.

Quite a can of worms!!!!!

The 3550 only seems to do:-
port-channel load-balance {dst-mac | src-mac}
This goes on the physical interface.

If your traffic is between two hosts you may be out of luck.

In interesting wee problem.