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Beginner

Etherchannel PAGP Problem

Hello my friends!

I created 1 ether channel between 4503E and 2960 TTL on 2 ports.

Ether channel ist up but can not load balancing on 2 port. all traffics pass 1 port. The real bw monitor attached.

where is my problem?

Everyone's tags (1)
2 ACCEPTED SOLUTIONS

Accepted Solutions
Highlighted
Cisco Employee

Re: Etherchannel PAGP Problem

Hello,

 

Are you doing a file transfer from the same source to the same destination? Etherchannel does per flow load balancing and not per packet. Might be expected if you only have one source and one destination. 

 

Hope that helps!

-Bradley Selzer
CCIE# 60833

View solution in original post

VIP Advisor

Re: Etherchannel PAGP Problem

This is what I mentioned earlier about single host to single host. The load-balancing is done per flow, not per packet. Therefore this single flow will only use one link in a port-channel.

 

cheers,

Seb.

View solution in original post

13 REPLIES 13
VIP Advisor

Re: Etherchannel PAGP Problem

Hi there,

This is most likely an issue with the load balancing algorithm used on either end of the link:

show etherchannel load-balance

 

...you need to understand the type of traffic flows traversing the link to choose the best algorithm.

 

cheers,

Seb.

Beginner

Re: Etherchannel PAGP Problem

thanks Rupik! i changed load balance algorithm on both switches to src-dst-ip, but still there is a problem. I tested other load balance algorithm on both switches!

VIP Advisor

Re: Etherchannel PAGP Problem

Can you share the output of sh etherchannel from both ends?

 

Also, what is the src/dest composition of the traffic over the etherchannel. As an extreme example, is it a single host to single host? An entire subnet to a single host? A range of subnets sending traffic off to the internet?

 

cheers,

Seb.

Beginner

Re: Etherchannel PAGP Problem

2960-u7#sh etherchannel
Channel-group listing:
----------------------

Group: 1
----------
Group state = L2
Ports: 2 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: PAgP
Minimum Links: 0

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

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

4503-core-switch#sh etherchannel
Channel-group listing:
----------------------

Group: 1
----------
Group state = L2
Ports: 2 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: PAgP

Group: 2
----------
Group state = L2
Ports: 2 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: PAgP

Group: 3
----------
Group state = L2
Ports: 2 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: PAgP

Group: 4
----------
Group state = L2
Ports: 2 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: PAgP

Group: 5
----------
Group state = L2
Ports: 2 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: PAgP

Group: 6
----------
Group state = L2
Ports: 2 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: PAgP

Group: 7    ------------->> to 2960
----------
Group state = L2
Ports: 2 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: PAgP

Group: 11
----------
Group state = L2
Ports: 4 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: LACP

Group: 12
----------
Group state = L2
Ports: 4 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: LACP

Group: 13
----------
Group state = L2
Ports: 4 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: LACP

Group: 41
----------
Group state = L2
Ports: 3 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: LACP

Group: 42
----------
Group state = L2
Ports: 3 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: LACP

Group: 43
----------
Group state = L2
Ports: 3 Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol: LACP

 

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

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

load balance algorithm is src-dst-ip in both switches.
im using a few subnet in my network. this subnet for test is : on client side : 172.31.12.0/24 and on server side is 192.168.25.0/24 
client subnets sending traffics to internet.

 

 

VIP Collaborator

Re: Etherchannel PAGP Problem

Hello, as Rupik said, maybei it is a loabalance algorithm, you can try change it.


Check this link with some exemples: https://community.cisco.com/t5/switching/3750x-stack-changing-etherchannel-load-balance-configuration/td-p/2062317
Jaderson Pessoa
*** Rate All Helpful Responses ***
Beginner

Re: Etherchannel PAGP Problem

thanks Pessoa! But still there is a problem with ether channel. still pass all traffics on 1 port.

VIP Collaborator

Re: Etherchannel PAGP Problem

Please, input here.

show etherchannel and show interface gi1/0/x (all ports in bundle)


Thanks.
Jaderson Pessoa
*** Rate All Helpful Responses ***
Beginner

Re: Etherchannel PAGP Problem

i wrote show etherchannel in the top.
4503-core-switch#show interfaces gigabitEthernet 2/47
GigabitEthernet2/47 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet Port, address is 0011.21e1.9cce (bia 0011.21e1.9cce)
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, link type is auto, media type is 10/100/1000-TX
input flow-control is off, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:13, 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: 64497
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 264000 bits/sec, 36 packets/sec
415284937 packets input, 143001564621 bytes, 0 no buffer
Received 4908216 broadcasts (2939647 multicasts)
0 runts, 0 giants, 0 throttles
1 input errors, 1 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
496858041 packets output, 443623736738 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
4503-core-switch#show interfaces gigabitEthernet 3/47
GigabitEthernet3/47 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet Port, address is 0011.21e1.6b1e (bia 0011.21e1.6b1e)
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, link type is auto, media type is 10/100/1000-TX
input flow-control is off, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:15, 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: 11433
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 45000 bits/sec, 36 packets/sec
5 minute output rate 81000 bits/sec, 19 packets/sec
241171124 packets input, 70445382878 bytes, 0 no buffer
Received 3896870 broadcasts (3156775 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
502804639 packets output, 545082123255 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

 

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

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

2960-u7#show interfaces gigabitEthernet 0/1
GigabitEthernet0/1 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 001b.0c5e.e931 (bia 001b.0c5e.e931)
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Full-duplex, 1000Mb/s, link type is auto, 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 00:00:00, output 00:00:11, 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 259000 bits/sec, 36 packets/sec
5 minute output rate 2000 bits/sec, 3 packets/sec
1039634412 packets input, 1037913899097 bytes, 0 no buffer
Received 126901067 broadcasts (97923696 multicasts)
0 runts, 0 giants, 0 throttles
14 input errors, 5 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 97923696 multicast, 0 pause input
0 input packets with dribble condition detected
770108611 packets output, 265128136012 bytes, 0 underruns
0 output errors, 0 collisions, 1 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
2960-u7#show interfaces gigabitEthernet 0/2
GigabitEthernet0/2 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 001b.0c5e.e932 (bia 001b.0c5e.e932)
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Full-duplex, 1000Mb/s, link type is auto, 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 00:00:13, output 00:00:08, 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 72000 bits/sec, 20 packets/sec
5 minute output rate 36000 bits/sec, 33 packets/sec
502798159 packets input, 545079999948 bytes, 0 no buffer
Received 28543471 broadcasts (8801912 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 8801912 multicast, 0 pause input
0 input packets with dribble condition detected
241163676 packets output, 70444041858 bytes, 0 underruns
0 output errors, 0 collisions, 1 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

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

4503-core-switch#show interfaces port-channel 7
Port-channel7 is up, line protocol is up (connected)
Hardware is EtherChannel, address is 0011.21e1.6b1e (bia 0011.21e1.6b1e)
MTU 1500 bytes, BW 2000000 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 N/A
input flow-control is off, output flow-control is unsupported
Members in this channel: Gi2/47 Gi3/47
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:13:55, 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: 66404
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 33000 bits/sec, 33 packets/sec
5 minute output rate 341000 bits/sec, 60 packets/sec
640078444 packets input, 207634306713 bytes, 0 no buffer
Received 8562131 broadcasts (5932974 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
975362652 packets output, 965665228936 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

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

-----------

2960-u7#show interfaces port-channel 1
Port-channel1 is up, line protocol is up (connected)
Hardware is EtherChannel, address is 001b.0c5e.e932 (bia 001b.0c5e.e932)
MTU 1500 bytes, BW 2000000 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, link type is auto, media type is unknown
input flow-control is off, output flow-control is unsupported
Members in this channel: Gi0/1 Gi0/2
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:06, 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 332000 bits/sec, 57 packets/sec
5 minute output rate 32000 bits/sec, 32 packets/sec
975362326 packets input, 965665927212 bytes, 0 no buffer
Received 118859951 broadcasts (84875519 multicasts)
0 runts, 0 giants, 0 throttles
2 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 84875519 multicast, 0 pause input
0 input packets with dribble condition detected
640079296 packets output, 207634419650 bytes, 0 underruns
0 output errors, 0 collisions, 1 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

 

Highlighted
Cisco Employee

Re: Etherchannel PAGP Problem

Hello,

 

Are you doing a file transfer from the same source to the same destination? Etherchannel does per flow load balancing and not per packet. Might be expected if you only have one source and one destination. 

 

Hope that helps!

-Bradley Selzer
CCIE# 60833

View solution in original post

Beginner

Re: Etherchannel PAGP Problem

source address is 172.31.12.159 destination address is 192.168.25.131 

and i want to copy file from source to destination.

Like the picture. i attached.

VIP Advisor

Re: Etherchannel PAGP Problem

This is what I mentioned earlier about single host to single host. The load-balancing is done per flow, not per packet. Therefore this single flow will only use one link in a port-channel.

 

cheers,

Seb.

View solution in original post

Beginner

Re: Etherchannel PAGP Problem

thanks Rupik and thanks brselze!
Problem resolved.
So the load balance base on total traffic on all source and destination, not from 1 source and 1 destination.
i tested with 2 source (last bit on sources is different after xor) on 1 destination. and hash algorithm is src-dst-ip and load balancing was done.
Thanks
VIP Advisor

Re: Etherchannel PAGP Problem

Correct. Each flow is evaluated by the hashing algorithm as it is about to be forwarded over the etherchannel. It will continue to use that member link for the duration of the flow. It is quite likely that in a production network you will never achieve perfect load-balancing across member links.

 

cheers,

Seb.

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