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9.5K Posts

January 21st, 2015 11:00

“ I understand, and it makes sense, in a way. But wasting a port to achieve this seem like a strange strategy. Must be another way”

 

 

The strategy is to connect orphan devices to a partner switch which does have a VPC link back to both partner swtches. MLAG and VLT, though conceptually similar, and existing on two switch platforms owned by the same company, are running different OSes and don’t work the same way.

As the white paper I referenced to you originally pointed out (page 23), there are plans to address the “single-home / orphan device connected directly to a primary or secondary peer switch” scenario, by using a secondary, redundant, port-channel between the peer switches to pass traffic for just those single-homed/orphan devices. One critical aspect of this planned implementation is that the VLANs used by single-homed/orphan devices cannot also be passed on the peer-link port-channel (because of the obvious loop that would occur).

 

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Did not work either. It does not ping

Po23 is a device on port 1/0/23 on SW2

ME_Core_Switch2 is the Primary peer. The described workaround functions only for devices that are physically connected to the secondary peer. This would let an orphan/single-home device on the secondary peer communicate with either:
            A device that is connected to both peers with a vpc port-channel (i.e. a partner switch or partner host); OR
            A device connected to that partner switch; OR
           A single-home/orphan device connected to the same (i.e. secondary peer)

A single-home/orphan device physically connected to the primary peer will never be able to communicate properly.

Po46 is my computer on port 1/0/46 on SW1

ME_Core_Switch1(config)#do show vpc bri

VPC admin status............................... Enabled

Keep-alive admin status........................ Enabled

VPC operational status......................... Enabled

Self role...................................... Secondary

Peer role...................................... Primary

Peer detection admin status.................... Peer detected, VPC Operational

Peer-Link details

VPC id# 23

-----------

Interface...................................... Po23

Configured VLANs............................... 20

VPC interface state............................ Active

Local Members Status

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

Gi1/0/23 DOWN << THIS IS WRONG

Peer Members Status

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

VPC id# 46

-----------

Interface...................................... Po46

Configured VLANs............................... 20

VPC interface state............................ Active

Local Members Status

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

Gi1/0/46 Up << THIS IS CORRECT

Peer Members Status

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

ME_Core_Switch2(config-if-Po46)#do show vpc bri

VPC admin status............................... Enabled

Keep-alive admin status........................ Enabled

VPC operational status......................... Enabled

Self role...................................... Primary

Peer role...................................... Secondary

Peer detection admin status.................... Peer detected, VPC Operational

Peer-Link details

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

Interface...................................... Po1

Peer-link admin status......................... Enabled

Peer-link StP admin status..................... Disabled

Configured VLANs............................... 1,10,20,30,40,60,100,170,192

Egress tagged VLANs............................ 10,20,30,40,60,100,170,192

VPC Details

-----------

Number of VPCs configured...................... 2

Number of VPCs operational..................... 2

VPC id# 23

-----------

Interface...................................... Po23

Configured VLANs............................... 20

VPC interface state............................ Active

Local Members Status

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

Gi1/0/23 Up << THIS IS WRONG

Peer Members Status

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

Gi1/0/23 DOWN

VPC id# 46

-----------

Interface...................................... Po46

Configured VLANs............................... 20

VPC interface state............................ Active

Local Members Status

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

Gi1/0/46 DOWN << THIS IS CORRECT

Peer Members Status

Moderator

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9.5K Posts

January 12th, 2015 14:00

Hi,

It sounds like just the peer link is not transmitting traffic and the partner switches that connect to both peers works fine. Can you post the peer configuration from the switches? Page 9 of the MLAG guide shows an example of the config. http://en.community.dell.com/techcenter/extras/m/white_papers/20438244

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16 Posts

January 12th, 2015 16:00

Strange thing is, from SW1 I can sucessfully ping SW2 in VLAN 20

But if one device is connected in VLAN 20 in SW1 it cannot ping device in VLAN 20 in SW2

And I cannot event ping SW2 from a device in VLNA 20 in SW1

Thanks for your help!

There you go:

SW1

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

!Current Configuration:

!System Description "Dell Networking N3048, 6.1.0.6, Linux 3.6.5-320b2282"

!System Software Version 6.1.0.6

!

configure

vlan 10

exit

vlan 20

exit

vlan 30

exit

vlan 40

exit

vlan 60

exit

vlan 100

exit

vlan 170

exit

vlan 10,20,30,40,60,100,170,192

exit

ip telnet server disable

slot 1/0 3    ! Dell Networking N3048

sntp unicast client enable

clock timezone -5 minutes 0

stack

member 1 4    ! N3048

stack-port Tw1/0/1 shutdown

stack-port Tw1/0/2 shutdown

exit

logging 10.160.1.2

level warnings

exit

ip http secure-server

no ip http server

interface vlan 1

ip address dhcp

exit

interface vlan 20

ip address 192.168.200.253 255.255.255.0

exit

username "bob" password 47a38f349d882967354e37fe4ebfe92b3bf privilege 15 encrypted

ip ssh server

spanning-tree priority 0

spanning-tree mode rapid-pvst

!

interface Gi1/0/1

switchport access vlan 20

exit

!

interface Gi1/0/2

switchport access vlan 20

exit

!

interface Gi1/0/3

switchport access vlan 20

exit

!

interface Gi1/0/48

channel-group 1 mode active

description "VPC_Temp"

udld enable

udld port aggressive

exit

!

interface gi1/0/47

switchport access vlan 20

exit

!

18777475005

ass mieux etre

c02926223

interface port-channel 1

description "VPC_PeerLink"

switchport mode trunk

vpc peer-link

exit

snmp-server engineid local 800002a203f8b156619e64

enable password b73981e6dbbf5e11dbb806905dd6b4aa encrypted

feature vpc

vpc domain 1

role priority 10

peer-keepalive enable

peer-keepalive destination 192.168.200.254 source 192.168.200.253

peer detection enable

exit

exit

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

SW2

!Current Configuration:

!System Description "Dell Networking N3048, 6.1.0.6, Linux 3.6.5-320b2282"

!System Software Version 6.1.0.6

!

configure

vlan 10

exit

vlan 20

exit

vlan 30

exit

vlan 40

exit

vlan 60

exit

vlan 100

exit

vlan 170

exit

vlan 192

exit

vlan 10,20,30,40,60,100,170,192

exit

ip telnet server disable

hostname "ME_Core_Switch2"

slot 1/0 3    ! Dell Networking N3048

sntp unicast client enable

clock timezone -5 minutes 0

stack

member 1 4    ! N3048

stack-port Tw1/0/1 shutdown

stack-port Tw1/0/2 shutdown

exit

level warnings

exit

ip http secure-server

no ip http server

interface vlan 1

ip address dhcp

exit

interface vlan 20

ip address 192.168.200.254 255.255.255.0

exit

username "bob" password 47a38f34929dd5467354e37fe4ebfe92b3bf privilege 15 encrypted

ip ssh server

spanning-tree priority 4096

spanning-tree mode rapid-pvst

!

interface Gi1/0/1

switchport access vlan 20

exit

!

interface Gi1/0/2

switchport access vlan 20

exit

!

interface Gi1/0/3

switchport access vlan 20

exit

!

interface Gi1/0/48

channel-group 1 mode active

description "VPC_Temp_Link"

udld enable

udld port aggressive

exit

!

interface port-channel 1

description "VPC_Temp_Core"

switchport mode trunk

vpc peer-link

exit

snmp-server engineid local 800002a203f8b156619fe0

enable password b73981e6dbbf5e11dbb806905dd6b4aa encrypted

feature vpc

vpc domain 1

role priority 20

peer-keepalive enable

peer-keepalive destination 192.168.200.253 source 192.168.200.254

peer detection enable

exit

exit

Moderator

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9.5K Posts

January 12th, 2015 17:00

Let’s make sure that spanning-tree isn’t blocking the port, can you run show spanning-tree blockedports and make sure the port channel is not one of the ports?

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16 Posts

January 12th, 2015 19:00

Yeah I'Ve checked.

And as soon as I disable VPC feature, all goes well...

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16 Posts

January 13th, 2015 11:00

Already did...

Moderator

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9.5K Posts

January 13th, 2015 11:00

Can you try updating to the latest firmware? [View:www.dell.com/.../DriversDetails]

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9.5K Posts

January 13th, 2015 13:00

The issue may be that there are orphan ports, which the N series doesn’t have support for when using MLAG. You can create a static LAG and disconnect one port and that should work if the active interface is on the VPC secondary switch.

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16 Posts

January 14th, 2015 05:00

Interesting

Worth trying.

I'll give you results tomorrow

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16 Posts

January 14th, 2015 05:00

With Force10 VLT, it is recommended to use a Static LAG for the peer link, I always wondered why it was not the case for the N3000 VPC

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16 Posts

January 19th, 2015 07:00

I found out that both my switchs see themselfs as Root for spanning-tree

Think it might be the problem?

I tried to change the priority, but it does not work

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9.5K Posts

January 19th, 2015 09:00

It could be a problem, what spanning tree mode is it in, you could disable spanning-tree on one of the switches.

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16 Posts

January 20th, 2015 04:00

I manage to make it work correctly, with one switch being the root, and all ports are fowarding state

But as soon as I enable VPC Mlag, no communication pass between the 2 switchs exept a ping to each other. A server connected to one switch cannot ping another on the opther switch but same VLAN

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9.5K Posts

January 20th, 2015 08:00

Ok, so that rules out spanning-tree, were you able to switch to a static LAG as well?

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16 Posts

January 20th, 2015 09:00

Yes, but it did not work either

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