MLAG algorithm when connected to Juniper Switches.

[Rod_Robertson2]

I have a customer who has a core of Extreme , and Juniper edge .

We seem to have an issue with Mlag.
The config looks OK , only thing different to my configuration is that the ISC is in its own VR, I do not see an issue with that ..

The problem that is being reported , is that the edge switches ( juniper when configured for AE0, the transfer of data is extremely slow.

Remove one of the mlag links and it all speeds up to an acceptable level.

We are not running LACP..

Juniper Edge config.

set interfaces ae0 description xe-uplinks-LAG set interfaces ae0 aggregated-ether-options minimum-links 1
set interfaces ae0 aggregated-ether-options link-speed 10g
set interfaces ae0 unit 0 family ethernet-switching port-mode trunk

set interfaces xe-0/1/0 ether-options 802.3ad ae0
set interfaces xe-0/1/1 ether-options 802.3ad ae0

Extreme config :

One side only ..

create vr "VR-MLAG-ISC"
create vlan "MLAG-ISC" vr VR-MLAG-ISC
configure vlan MLAG-ISC tag 6
configure vlan "MLAG-ISC" qosprofile QP5
configure vlan MLAG-ISC add ports 1:39 tagged
configure vlan MLAG-ISC ipaddress 10.10.10.1 255.255.255.252
disable iproute ipv4 compression vr VR-MLAG-ISC
disable iproute ipv6 compression vr VR-MLAG-ISC
create mlag peer "CL-MLAG"
configure mlag peer "CL-MLAG" ipaddress 10.10.10.2 vr VR-MLAG-ISC enable mlag port 1:43 peer "CL-MLAG" id 1
enable mlag port 1:44 peer "CL-MLAG" id 2
enable mlag port 1:45 peer "CL-MLAG" id 3
enable mlag port 1:46 peer "CL-MLAG" id 4
enable mlag port 1:47 peer "CL-MLAG" id 5
enable mlag port 1:48 peer "CL-MLAG" id 6

Ok this is more than I would configure normally for MLAG..(QOS IProute Compression )..

My main question is :

What hashing algorithm does Mlag use , its construction and can it be modified ,

I expect the issue to be the difference between Juniper and Extreme Algorithms ... well I hope it is , if this cannot be resolved , the customer will be returning to EAPS.

Many Thanks

Rod

[Patrick_Voss]

Hi Rod,

At first glance I believe that ISC being put into a different VR is in fact causing the issue you are seeing. It is probably causing an issue with the blocking MLAG is supposed to perform. Would it be possible to change it? I don't see any advantage to having the ISC in a different VR.

[Henrique]

Hi Rob, I don't see the sharing enabled (link-agregation) on EXOS switch.

Could you please share this configuration?

You must enable sharing in EXOS port connecting to Juniper even if using just one link.

[Rod_Robertson2]

Hi We are using static lag on the juniper and no LACP.

[Henrique]

Just a correction. This is needed only when using LACP, not for Static LAG.

[Rod_Robertson2]

LOL This was not installed by me, though I have to support it .. and I cant ask the original engineer as they are long gone.

Normally with Mlag I dont seem to get these problems when running extreme everywhere.

The answer is I dont know why they created a seperate VR normally I would just put it in the VR-default ( which at the end of the day is just another VR right !!! ? )

The issue we are having is that when mlag is in and working ( or not ) the performance on the links to and from the juniper switches is unworkable ..remove one of the link , hay presto all works OK.