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I am posting a config on a set of Arista switches which utilise mLag which is basically multichassis link aggregation. This allows you to have a host or device connected to two seperate switches and it allows you to cover the hosts for redundancy. <p> </p>
Normally if you attach a device for redundancy to two switches spanning tree will block the alternative port. Mlag bypasses this as it sees the swiching area as a single domain or virtual switch.
Anyway, lets look at the config, I am taking to defaulted switches – two 24 port 7050 10GBE switches. I will be using port 22 and 23 as port channels, and i will use these as peer links. The Peer link is important as it shares domain information and maintains a heartbeat between the switches. Im not going over the basic config of the switch like management IP etc, i assume you have configured this already.
First we configure the peer link for mlag, this creates a local interface and associates it to the trunk group for the peer link. STP is disabled for this link
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Switch01 –
interface ethernet 22-23
channel-group 102 mode active
interface port-channel 101
switchport mode trunk
switchport trunk group m01peer
exit
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Switch02 –
interface ethernet 22-23
channel-group 101 mode active
interface port-channel 101
switchport mode trunk
switchport trunk group m02peer
exit
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Next we can configure VLAN for the mlag heartbeat and communication.
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Switch01 –
vlan 4094
trunk group mlag01
interface vlan 4094
ip address 10.0.0.1/30
no autostate
exit
no spanning-tree vlan 4094
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Switch02 –
vlan 4094
trunk group mlag02
interface vlan 4094
ip address 10.0.0.4/30
no autostate
exit
no spanning-tree vlan 4094
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Lastely we can configure the peer links for the machines you want to connect to the mlag environment.
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Switch01 –
interface ethernet 1
description SW01_Machine01
channel-group 1 mode active
interface port-channel 1
mlag 1
exit
interface ethernet 2
description SW01_Machine02
channel-group 2 mode active
interface port-channel 2
mlag 2
exit
interface ethernet 3
description SW01_Machine03
channel-group 3 mode active
interface port-channel 3
mlag 3
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Switch02 –
interface ethernet 1
description SW02_Machine01
channel-group 1 mode active
interface port-channel 1
mlag 1
exit
interface ethernet 2
description SW02_Machine02
channel-group 2 mode active
interface port-channel 2
mlag 2
exit
interface ethernet 3
description SW02_Machine03
channel-group 3 mode active
interface port-channel 3
mlag 3
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Once you can completed this you can test the system and config by checking the mlag.
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Switch1#
show mlag
MLAG Configuration:
domain-id :
local-interface :
peer-address :
peer-link :
MLAG Status:
state :
peer-link status :
local-int status :
system-id :
MLAG Ports:
Disabled
Configured :
Inactive :
Active-partial :
Active-full :
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mlag
Vlan4094
10.0.0.2
Port-Channel101
Active
Up
Up
02:1c:FF:00:15:38
0
3
0
0
3
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Hmm it seems like your site ate my first
comment (it was super long) so I guess I’ll just
sum it up what I had written and say, I’m thoroughly enjoying your
blog. I too am an aspiring blog writer but I’m still new
to everything. Do you have any points for novice blog writers?
I’d really appreciate it.
Highly descriptive post, I loved that bit.
Will there be a part 2?
It’s difficult to find educated people in this particular subject,
but you seem like you know what you’re talking about!
Thanks