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Go to SolutionMLAG (VPC) N3000 connectivity issue
Hi there,
I'm a little new to the MLAG of the N3000, but not the VLT of the Force10, but somehow, something is not behaving the same way, or I am missing something.
I have 2 switchs, connected together by a Port-channel in trunk mode and MLAG
Eventhough the MLAG is up and running, and the Port-Channel linking both peers is in trunk mode for all VLANs, I cannot connect to a device on the same vlan that is connected to the other switch. But If i connect a PC to a partner switch, I can connect to any device connected to either one or the other peer switch.
Any ideas why the peer link is behaving that way?
Thanks for your help!
DELL-Josh Cr
Community Manager
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Posted 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
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
DELL-Josh Cr
Community Manager
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45028 Points
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Posted 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?
DELL-Josh Cr
Community Manager
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45028 Points
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Posted January 13th, 2015 11:00
Can you try updating to the latest firmware? [View:www.dell.com/.../DriversDetails]
DELL-Josh Cr
Community Manager
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45028 Points
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Posted 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.
DELL-Josh Cr
Community Manager
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45028 Points
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Posted 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).
---------
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