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N3024 VPC/MLAG Configuration Issue/?
2 Dell N3024's (both running 6.1.2.4 software).
The layout here is:
3024-sw1 (Te1/0/2) uplinked to core-sw1 (Happens to be an Arista)
3024-sw2 (Te1/0/2) uplinked to core-sw2 (Happens to be an Arista)
3024-sw1 (Te1/0/1) connected to 3024-sw2 (Te1/0/1) via 10Gb fiber
Basically I want the two N3024's to be MLAG to the core-sw1/2, and I need the two Dells "stacked" but w/o a stacking cable, via MLAG/VPC etc.
As it stands, when this is setup, I have devices that are not reachable on 3024-sw1, unless the link from 3024-sw2 to the core-sw2 is down. MLAG is configured on both cores to each Dell with associated port-channels etc.
I'll gather configs and post them shortly.
In the mean time:
Why do I need to disable spanning-tree on these port-channels to make MLAG work?
Do the Dell's NEED 2 physical links in an MLAG/VPC to work?
Thanks!
Anonymous
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March 5th, 2015 13:00
Here is a good guide to setting up MLAG. Might look through it and double check your current config.
http://dell.to/WQYhQu
Are core switch 1 and 2 stacked with each other?
jdurling
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March 6th, 2015 04:00
Core switch 1 / 2 are setup with a port-channel together/MLAG etc.
Anonymous
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March 6th, 2015 06:00
I put together a quick diagram of how I envision your network. Just want to be sure we are on the same page.
Is this correct?
jdurling
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March 6th, 2015 07:00
That is correct.
As it stands, I have a device hanging off 3024-sw1, that is pingable from 3024-sw1, and core1, but not 3024-sw2 or the core2. If the link between core2 and 3024-sw2 is down, the device will become reachable. from everything EXCEPT 3024-sw2. Leads me to think there is an issue with the config between the two 3024's on port-channel 50.
3024-sw1
interface Te1/0/1
channel-group 50 mode active
description "MLAG Peer to 3024-sw2"
exit
interface Te1/0/2
channel-group 1 mode active
description "LAG to core1"
exit
interface port-channel 1
description "LAG to core1"
switchport mode trunk
switchport trunk allowed vlan 100
vpc 1
exit
interface port-channel 50
description "Trunk to 3024-sw2"
switchport mode trunk
vpc peer-link
exit
feature vpc
vpc domain 1
role priority 10
peer-keepalive enable
3024-sw2
interface Te1/0/1
channel-group 50 mode active
description "MLAG Peer to 3024-sw1"
exit
interface Te1/0/2
channel-group 1 mode active
description "LAG to core2"
exit
interface port-channel 1
description "LAG to core2"
switchport mode trunk
switchport trunk allowed vlan 100
vpc 1
exit
interface port-channel 50
description "Trunk to 3024-sw1"
switchport mode trunk
vpc peer-link
exit
feature vpc
vpc domain 1
role priority 10
peer-keepalive enable
core1
interface Port-Channel1
description MLAG Trunk to 3024-sw1
switchport trunk allowed vlan 100
switchport mode trunk
mlag 5
interface Ethernet3/4
description MLAG to 3024-sw1
channel-group 1 mode active
core2
interface Port-Channel1
description MLAG Trunk to 3024-sw2
switchport trunk allowed vlan 100
switchport mode trunk
mlag 5
interface Ethernet3/4
description MLAG to 3024-sw2
channel-group 1 mode active
I have had working MLAG configs between core1 & 2, with this setup using other switches, which leads me to believe I am just missing something on configuring these Dell N3000 switches.
I had been looking through the MLAG guide link you provided already.
The only thing I can see I didn't do as of yet was remove "spanning-tree" from the port-channel 50 (between 3024-sw1 & 3024-sw2).
*sorry if these configs didn't display well, I wasn't having much luck with typing them into the post box.
Anonymous
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March 6th, 2015 07:00
when looking at the status of port 1/0/2 on both 3024 switch, are they both up? # show spanning-tree
Everything I have looked at suggests that STP should be disabled on the peer links. we should proceed with disabling it on the peer links and test for any behavior changes.
Anonymous
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March 6th, 2015 08:00
Sorry, your right, the port channel needs to have spanning tree disabled.
jdurling
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March 6th, 2015 08:00
To add to that though:
port-channel 50, which is the port-chan between the two 3024's shows:
3024-sw1
Po50 Enabled 96.699 2000 FWD Desg No
3024-sw2
Po50 Enabled 96.699 2000 FWD Root No
I'm not sure how spanning-tree will appear on physical links vs. port-channels and if this is indicative of anything.
jdurling
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March 6th, 2015 08:00
The states are "Enabled", but neither shows as FWD;ing.
Te1/0/2 Enabled 128.28 0 DIS Disb No
Te1/0/2 Enabled 128.26 0 DIS Disb No
Disable spanning tree on the port-channels or the actual physical Te1/0/2 interfaces?
Anonymous
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March 6th, 2015 08:00
interface port-channel 50
spanning-tree disable
Then that link between the two 3024 switches should have spanning tree disabled.
jdurling
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March 6th, 2015 08:00
I disabled that on both 3024's for port-channel 50.
Po50 Enabled 96.699 2000 FWD Desg No
Po50 Enabled 96.699 2000 FWD Desg No
As it stands, that didn't change anything in regards to being able to ping the device on the 3024-sw1 from the 3024-sw2.
Anonymous
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March 6th, 2015 10:00
I sent you a PM with my email address. Could you email me the output from [tag:show] tech, from both switches. This will help me look further into whats going on.
Thanks
CBrasga
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September 18th, 2015 02:00
According to the Using MLAG in Dell Networks document, Peer Links will not carry non-LAG traffic. So even though you have an uplink between the switches, since you defined it as an Peer Link it won't pass the traffic.
Check out the section on Single Homed Partners. "Traffic to and from non-redundant ports is filtered and never crosses the MLAG Peer-Link."