11-06-2005 11:44 PM - edited 03-03-2019 12:42 AM
Hi
I have two Switches (4948) i want to connect via 2 GigabitEthernet Ports. The two Ports should build a Channel and forward all VLANs.
Heres the config i enterd on both switches:
!
interface Port-channel1
switchport
!
interface GigabitEthernet1/47
switchport trunk encapsulation dot1q
switchport mode trunk
speed 1000
duplex full
channel-group 1 mode auto
!
interface GigabitEthernet1/48
switchport trunk encapsulation dot1q
switchport mode trunk
speed 1000
duplex full
channel-group 1 mode auto
The two Switches are already connected, but i don't think that the channel is working correct cause this:
Port-channel1 is down, line protocol is down (notconnect)
Hardware is EtherChannel, address is 0000.0000.0000 (bia 0000.0000.0000)
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Auto-duplex, Auto-speed, media type is N/A
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/2000/0/0 (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
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts (0 multicast)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Both channel Ports are up and show a mediaspeed of 1000Mbit full-duplex. But just one of them has an significant Traffic.
I think that the Channel-Group has to be up and not down. I also wonder why the mediaspeed is just set to 100Mbit
If the Channel is working (in this or a little modified configuration) how will the traffic flow?
Balanced over both Ports? Just one Port and if the Traffic is too high also over the second port?
Thank you very much for helping me!
11-07-2005 07:51 AM
Hi
Try using channel-group 1 mode desirable on the ports instead.
Load balancing is done based on the source MAC by default - the following command shows your load -balance method:
show etherchannel load-balance
The switch will put some traffic over one link and some over the other, but depending on your network it might be uneven.
Regards
Aaron
p.s. please rate helpful posts...
11-07-2005 10:30 AM
The etherchannel is not working if the portchannel is down . Do a "show etherchannel detail and see what state the channel is in , though it should show that it is down if the port channel is down . You have the ports set as auto on the channel so in order for that to work the far cisco switch has to be set as desirable (otherwise it won't come up) and it is recomended that it be mode non-silent between cisco devices . Also I would pull the speed/duplex settings and leave it as auto , it will negotiate the highest available speed between the switches . Both ends should be auto for speed/duplex .
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide