Load Balancing across links in a linkaggregation

helmers · Post by **helmers** » 22 Feb 2010 17:40

Hi,

in need to know how the traffic is load balanced across the links in a linkaggregation. Is the distribution based on MAC-addresses or IP-addresses or is it a complete other algorithm?
Is it possible to change the load balancing method?

Best Regards
Helmut

benny · Post by **benny** » 23 Feb 2010 01:07

Hi Helmut,

Welcome to the board!

Yes, since AOS 6.4.2.R01 you can modify the way the traffic is load-balanced over a link-aggregation.

Code: Select all

OS6855-LAB-> show hash-control 
Hash Mode    = brief,
Udp-Tcp-Port = disabled

The mode you are looking for is "extended". You'll find everything you need in the documentation available through the link in my signature.

cedric1 · Post by **cedric1** » 23 Feb 2010 11:14

and in complement hashing is dependent on RFC 2292.
same hashing is used for SLB, Linkagg and ECMP.

Cedric

agungaryo · Post by **agungaryo** » 25 Feb 2010 12:45

I'm using AOS 6.3.4.399.R01 ,could I use "load-balancing" over linkagg ?

benny · Post by **benny** » 26 Feb 2010 02:28

The traffic is already load-balanced over the link aggregation. AOS 6.4.2.R01 just adds additional ways to look at the flows.

-benny

agungaryo · Post by **agungaryo** » 26 Feb 2010 09:04

hi benny,
I'm sorry for asking again,cause I'm still new.
I try in my switch :
Switch1# show linkagg port

Slot/Port Aggregate SNMP Id Status Agg Oper Link Prim
---------+---------+-------+----------+----+----+----+----
1/1 Dynamic 1001 ATTACHED 1 UP UP YES
1/2 Dynamic 1002 CONFIGURED NONE DOWN DOWN UNK
1/5 Dynamic 1005 ATTACHED 2 UP UP YES
1/6 Dynamic 1006 ATTACHED 2 UP UP NO
switch1# show linkagg 2

Dynamic Aggregate
SNMP Id : 40000002,
Aggregate Number : 2,
SNMP Descriptor : Dynamic Aggregate Number 2 ref 40000002 size 4,
Name : *****
Admin State : ENABLED,
Operational State : UP,
Aggregate Size : 4,
Number of Selected Ports : 2,
Number of Reserved Ports : 2,
Number of Attached Ports : 2,
Primary Port : 1/5
LACP
MACAddress : [*******],
Actor System Id : [00:00:00:00:00:00],
Actor System Priority : 0,
Actor Admin Key : 20,
Actor Oper Key : 20,
Partner System Id : [00:00:00:00:00:00],
Partner System Priority : 0,
Partner Admin Key : 0,
Partner Oper Key : 20

Switch1#

link-agg 2 use port 1/5 ,1/6 . I presumed, data is only go through port 1/5 (which is primary ).
is there any additional command to make link-agg as load balancer ?
I'm just using :
-> lacp linkagg 2 size 4 admin state enable
-> lacp linkagg 2 actor admin key 20
-> lacp agg 1/5 actor admin key 20
-> lacp agg 1/6 actor admin key 20

thank you,

agung aryo

agungaryo · Post by **agungaryo** » 26 Feb 2010 09:05

I've read documentation like this :
"Link aggregation groups are identified by unique MAC addresses, which are created by the switch but can
be modified by the user at any time. Load balancing for Layer 2 non-IP packets is on a MAC address basis
and for IP packets the balancing algorithm uses the IP address as well. Ports must be of the same speed
within the same aggregate group."
but I don't know technically.

thank you
agung aryo

cedric1 · Post by **cedric1** » 26 Feb 2010 12:44

what don't you know ?

agungaryo · Post by **agungaryo** » 26 Feb 2010 21:41

cedric1 wrote:what don't you know ?

Link-agg that's used as load balancer ,. . .

agungaryo wrote:hi benny,
I'm sorry for asking again,cause I'm still new.
I try in my switch :
Switch1# show linkagg port

Slot/Port Aggregate SNMP Id Status Agg Oper Link Prim
---------+---------+-------+----------+----+----+----+----
1/1 Dynamic 1001 ATTACHED 1 UP UP YES
1/2 Dynamic 1002 CONFIGURED NONE DOWN DOWN UNK
1/5 Dynamic 1005 ATTACHED 2 UP UP YES
1/6 Dynamic 1006 ATTACHED 2 UP UP NO
switch1# show linkagg 2

Dynamic Aggregate
SNMP Id : 40000002,
Aggregate Number : 2,
SNMP Descriptor : Dynamic Aggregate Number 2 ref 40000002 size 4,
Name : *****
Admin State : ENABLED,
Operational State : UP,
Aggregate Size : 4,
Number of Selected Ports : 2,
Number of Reserved Ports : 2,
Number of Attached Ports : 2,
Primary Port : 1/5
LACP
MACAddress : [*******],
Actor System Id : [00:00:00:00:00:00],
Actor System Priority : 0,
Actor Admin Key : 20,
Actor Oper Key : 20,
Partner System Id : [00:00:00:00:00:00],
Partner System Priority : 0,
Partner Admin Key : 0,
Partner Oper Key : 20

Switch1#

link-agg 2 use port 1/5 ,1/6 . I presumed, data is only go through port 1/5 (which is primary ).
is there any additional command to make link-agg as load balancer ?
I'm just using :
-> lacp linkagg 2 size 4 admin state enable
-> lacp linkagg 2 actor admin key 20
-> lacp agg 1/5 actor admin key 20
-> lacp agg 1/6 actor admin key 20

thank you,

agung aryo

benny · Post by **benny** » 27 Feb 2010 03:14

It will use both ports 1/5 and 1/6. The primary port just indicates on which link the Multicast packets, ARP etc are handled.

You don't have to do anything else.

-benny