Link aggregation Problems

[LugNut29]

Hey All,

I have a problem and need some help with two Stacked 3750G 48PT switches. We are trying to make the two switches become load balancers and Fail Overs for two IBM servers. I have created the Port-Channels and added the ports to the channels, but the problem is three of the ports go into a suspended state and will not come up. Is there something going on with my Config on the switches? I know the two NIC's on the servers are capable of doing this and are set up correctly with 802.3ad. I have included some of config to help with this.

Thanks,

Tom


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

interface Port-channel9
description LACP Portchannel for Server
switchport access vlan 2
switchport mode access
!
interface Port-channel10
description LACP Portchannel for Server
switchport access vlan 2
switchport mode access

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

interface GigabitEthernet1/0/21
description OHNetBackup1
switchport access vlan 2
switchport mode access
speed 1000
duplex full
channel-protocol lacp
channel-group 9 mode active
spanning-tree portfast
!
interface GigabitEthernet1/0/22
description OHNetBackup2
switchport access vlan 2
switchport mode access
speed 1000
duplex full
channel-protocol lacp
channel-group 10 mode active
spanning-tree portfast
!
interface GigabitEthernet2/0/21
description OHNetBackup1
switchport access vlan 2
switchport mode access
speed 1000
duplex full
channel-protocol lacp
channel-group 9 mode active
spanning-tree portfast
!
interface GigabitEthernet2/0/22
description OHNetBackup2
switchport access vlan 2
switchport mode access
speed 1000
duplex full
channel-protocol lacp
channel-group 10 mode active
spanning-tree portfast
!

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

Switch 1#sh int giga1/0/22
GigabitEthernet1/0/22 is up, line protocol is down (suspended)
Hardware is Gigabit Ethernet, address is 0023.eabc.dd16 (bia 0023.eabc.dd16)
Description: OHNetBackup2
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:03, output 00:00:03, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
1512018 packets input, 211162266 bytes, 0 no buffer
Received 94097 broadcasts (31892 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 31892 multicast, 0 pause input
0 input packets with dribble condition detected
6429822 packets output, 927095291 bytes, 0 underruns
0 output errors, 0 collisions, 9 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out

 

[Belushi]

It looks good from here. I see you are using LACP which is to be expected. I would check the server side.

 

[vipergg]

Are bringing it up via the port channel interface ? Do not try to bring up the ports individually. Do a shut on the port channel interface then a no shut and that will bring all up at the same time.

 

[LugNut29]

Did a shut and no shut on the port channel and they are still down.

 

[tjbradford]

either the server or the switch needs to take control of bringing the line up , one end can also be passive. check if your server is taking control or if you want the switch to, both normally are capable, try setting the switch to be in passive mode that might well bring up the link. this is from memory - i will also dig out my notes when im back at work.

 

[vipergg]

shouldn't matter if both sides are active . One side can be passive but it shouldn't matter if both sides are using LACP to form the channels. Do both switch ports show active ? The switch side looks fine , look at the server side .

 

[tjbradford]

arr,
is it across two switches config is suggesting so, there is limitations on this depending on the version of ios, have you tried lacp on the same switch instead of across two switches if that works then you need to get a later version of ios.

we had this a while back.