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How to do load balancing on Juniper QFX5100-48S Layer 2 interfaces

‎01-28-2020 11:18 AM

Hi There 

 

I have bonded 4  xe interfaces  of QFX5100 switch with our Server  via LACP . Please see below config of physical and their respetcive aggregated interface :

 

Physical interfaces config :

 

set interfaces xe-0/0/28 ether-options 802.3ad ae38

set interfaces xe-0/0/29 ether-options 802.3ad ae38

set interfaces xe-1/0/28 ether-options 802.3ad ae38

set interfaces xe-1/0/29 ether-options 802.3ad ae38

 

Aggregated Interface Config :


set interfaces ae38 aggregated-ether-options lacp active
set interfaces ae38 unit 0 family ethernet-switching interface-mode access
set interfaces ae38 unit 0 family ethernet-switching vlan members v0148

 

on the Server side we bond the below mentioned nics  

 

Nic12: 95:e2:ea:xx:xx:c1

Nic62: 95:e2:ca:xx:xx:4d

Nic82: 95:e2:ca:xx:xx:1d

Nic84: 95:e2:ca:xx:xx:1c

 

Now issue is we are seeing that traffic is going through only one Nic-62 from Server perspective . We want to distribute it on all four links of switches and Nics on the Server side . What configuration i need to change on Juniper switch side ? and if anything needs to be changed on Server side as well ?

Thanks 

6 REPLIES 6
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Ethernet Switching

Re: How to do load balancing on Juniper QFX5100-48S Layer 2 interfaces

‎01-28-2020 11:35 AM

Are you sending traffic to just one host? The hashing algorithm is based on values in various packet fields such as source and dest IP and ports, so a single large flow will not load balance. Can you post output of show lacp interface ae38 extensive, as well as similar from the host side?

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Ethernet Switching

Re: How to do load balancing on Juniper QFX5100-48S Layer 2 interfaces

‎01-28-2020 11:58 AM

Thanks smicker for the reply . basically the traffic which is going through is the streaming traffic ( IPTV ) traffic . So here i am confused that should i consider this traffic as L2 or Multicast traffic ? . If its multicast traffic then i guess different mechanism will be used to load balance it ? if yes then what it would be or still it would be same as L2 ? ( Source Mac /Port , Destination mac , Port ) ?

show lacp interface ae38 extensive command is not working .. instead i am pasting this : 

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

show lacp interfaces ae38

---------------------------------------
Aggregated interface: ae38
LACP state: Role Exp Def Dist Col Syn Aggr Timeout Activity
xe-1/0/28 Actor No No Yes Yes Yes Yes Fast Active
xe-1/0/28 Partner No No Yes Yes Yes Yes Fast Active
xe-1/0/29 Actor No No Yes Yes Yes Yes Fast Active
xe-1/0/29 Partner No No Yes Yes Yes Yes Fast Active
xe-0/0/28 Actor No No Yes Yes Yes Yes Fast Active
xe-0/0/28 Partner No No Yes Yes Yes Yes Fast Active
xe-0/0/29 Actor No No Yes Yes Yes Yes Fast Active
xe-0/0/29 Partner No No Yes Yes Yes Yes Fast Active
LACP protocol: Receive State Transmit State Mux State
xe-1/0/28 Current Fast periodic Collecting distributing
xe-1/0/29 Current Fast periodic Collecting distributing
xe-0/0/28 Current Fast periodic Collecting distributing
xe-0/0/29 Current Fast periodic Collecting distributing

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Ethernet Switching

Re: How to do load balancing on Juniper QFX5100-48S Layer 2 interfaces

‎01-28-2020 12:22 PM

Multicast definitely impacts the hashing process and I know that the QFX switches hash multicast differently. If the server is streaming multicast outbound (INTO the switch) then it is up to the server to balance the traffic properly across the four links. As with Juniper, there may be hashing options you need to modify serverp-side to handle multicast.

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Ethernet Switching

Re: How to do load balancing on Juniper QFX5100-48S Layer 2 interfaces

‎01-28-2020 12:33 PM

Our Server team guy is asking me to provide him (xmit hash policy  value ) which is configured on QFX5100 Switch . His idea is that by matching the same value on the servers he can align the load balancing on all the four server nics ? I am not sure is it the correct approach as i dont know if we have any (xmit hash policy value) configured on QFX5100 switch . 

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Re: How to do load balancing on Juniper QFX5100-48S Layer 2 interfaces

‎01-28-2020 12:44 PM

You can read about the supported hashing algorithm for LACP on QFX5100 in table 4 on this link: https://www.juniper.net/documentation/en_US/junos/topics/topic-map/switches-interface-aggregated.htm...

 

The link also provides general information on how hashing works and can be configuration.

 

You can also see how your QFX5100 are hashing via 'show forwarding-options enhanced-hash-key' - from my point I expect to use layer2-payload (meaning src/dst IP + ports) per default. If it's 'layer2-header' then change the hash-mode and test again.

 

If this is the case, your traffic is possible a single stream with the same src/dst IP + src/dst ports all the time... and that traffic will also stick a single 10G link. If you need higher bandwidth than this, you will have to use one of the 40G QSFP ports in the switch together with a 40G NIC in the server to provide higher throughput.

 

 


--
Best regards,

Jonas Hauge Klingenberg
Juniper Ambassador & Technology Architect, SEC DATACOM A/S (Denmark)
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Ethernet Switching

Re: How to do load balancing on Juniper QFX5100-48S Layer 2 interfaces

‎01-28-2020 02:20 PM

Thanks guys , I also did not notice that when we configure LACP on the juniper switch . On every physical interface . i can see packets transmitted so its means that by default on Juniper switch LACP will send traffic to every physical link under it . and issue only would be on the server side . so we need to check why we are seeing traffic on one NIC only out of 4 and whereas on switch side we are seeing traffic on all 4 physical interfaces.  

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