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Question

MLAG to MLAG (Extreme Only)


Userlevel 4
Create Date: Jul 15 2013 7:51AM

I'm trying to connect four extreme switches:

[a]---[b]
| |
[c]---[d]

A and B have an MLAG configured. So do C and D. Both MLAGs are connected together.
A+B are Summit X460 running 12.6.2.10. C+D are Summit X440 running 15.2.2.7
As soon as I enable more than one of the MLAG links, I get packet loss trying to ping across from C or D to A or B.

What's the problem?
Is it that MLAG can't work with another MLAG on the peer side?
Or do I just need to upgrade EXOS on the X460s? (from Chris_Burri)

5 replies

Userlevel 4
Create Date: Jul 16 2013 9:36PM

For your information:

I upgraded the 12.6.2.10 switches to 15.2.2.7, but MLAG to MLAG is a definitve no-go. I had to resort to RSTP.
Absolutely disappointing if you ask me - It would have been such an elegant solution offering redundancy and bandwidth.

Still I'd like to know why it doesn't work? MLAG is supposed to appear and act just like a normal LAG to the link partner. And since MLAG-LAG works fine, it really kinda annoys me that MLAG-MLAG does randomly blackhole my ethernet frames 😠

Any insight from the extremists here? (from Chris_Burri)
Userlevel 4
Create Date: Jul 31 2013 1:36PM

Can't you stack the switches? Easier than MLAG, and you get all redundancy and bandwidth.
(from Luis_Coelho)
Userlevel 4
Create Date: Aug 1 2013 9:52AM

Paste Your mlag configuration for all switches. I did not try this configuration but It should work. (from karpiu)
Userlevel 4
Create Date: Sep 7 2013 2:48AM

Chris, Two-tier MLAG definitely works.

Check this implementation guide
https://www.dropbox.com/s/pb4qsdzis05xg9y/SVC%20Tech%20DC%20Implementation%20Guide%20-%20Two%20Tier%20MLAG%20with%20EXOS%2012.6%20and%20Physical%20Servers%20v1.pdf (from Daniel_Flouret)
Userlevel 4
Create Date: Sep 11 2013 12:52PM

I have tested chris' topology with virtual exos and it worked ok. I will try with real switches sometime soon.
chris, please post your config so we can compare.
EXOS Version: 15.3.2.11

My topology:

[a]=[b]
| |
[c]=[d]

Switch A:
configure vlan default delete ports 1-7
create vlan "GerenciaRede"
configure vlan GerenciaRede tag 3
create vlan "isc"
configure vlan isc tag 2
enable sharing 1 grouping 1-2 algorithm roundRobin-based
configure vlan GerenciaRede add ports 1,5 tagged
configure vlan isc add ports 1 tagged
configure vlan Mgmt ipaddress 10.15.0.1 255.255.255.0
configure vlan isc ipaddress 10.6.5.1 255.255.255.0
configure vlan GerenciaRede ipaddress 10.6.4.10 255.255.255.0
create mlag peer "B"
configure mlag peer "B" ipaddress 10.6.5.2 vr VR-Default
enable mlag port 5 peer "B" id 56

Switch B:
configure vlan default delete ports 1-7
create vlan "GerenciaRede"
configure vlan GerenciaRede tag 3
create vlan "isc"
configure vlan isc tag 2
enable sharing 1 grouping 1-2 algorithm roundRobin-based
configure vlan GerenciaRede add ports 1, 6 tagged
configure vlan isc add ports 1 tagged
configure vlan Mgmt ipaddress 10.15.0.2 255.255.255.0
configure vlan isc ipaddress 10.6.5.2 255.255.255.0
configure vlan GerenciaRede ipaddress 10.6.4.20 255.255.255.0
create mlag peer "A"
configure mlag peer "A" ipaddress 10.6.5.1 vr VR-Default
enable mlag port 6 peer "A" id 56

Switch C:
configure vlan default delete ports 1-7
create vlan "GerenciaRede"
configure vlan GerenciaRede tag 3
create vlan "isc"
configure vlan isc tag 2
enable sharing 5 grouping 5-6 algorithm roundRobin-based
configure vlan GerenciaRede add ports 1, 5 tagged
configure vlan isc add ports 5 tagged
configure vlan Mgmt ipaddress 10.15.0.5 255.255.255.0
configure vlan isc ipaddress 10.5.0.5 255.255.255.0
configure vlan GerenciaRede ipaddress 10.6.4.201 255.255.255.0
create mlag peer "D"
configure mlag peer "D" ipaddress 10.5.0.6 vr VR-Default
enable mlag port 1 peer "D" id 12

Switch 😨
configure vlan default delete ports 1-7
create vlan "GerenciaRede"
configure vlan GerenciaRede tag 3
create vlan "isc"
configure vlan isc tag 2
enable sharing 5 grouping 5-6 algorithm roundRobin-based
configure vlan GerenciaRede add ports 2, 5 tagged
configure vlan isc add ports 5 tagged
configure vlan Mgmt ipaddress 10.15.0.6 255.255.255.0
configure vlan isc ipaddress 10.5.0.6 255.255.255.0
configure vlan GerenciaRede ipaddress 10.6.4.202 255.255.255.0
create mlag peer "C"
configure mlag peer "C" ipaddress 10.5.0.5 vr VR-Default
enable mlag port 2 peer "C" id 12



(from Luis_Coelho)

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