12-16-2015 11:21 AM - edited 03-08-2019 03:07 AM
I'm new to configuring vPC, but ran into a problem with a set of Nexus 5548s. When I add the vpc peer-link command to my port channel, SPT becomes unavailable for that interface. Note, I have the exact same configuration running on another set of 5548 (not connected to this set) with no issue. When SPT becomes unavailable, I'm no longer capable of reaching the mgmt interface of the peer Nexus. When the command is removed, I can ping across.
nx1
cfs eth distribute
feature lacp
feature vpc
feature lldp
feature ftp
spanning-tree vlan 1-3967 priority 4096
vrf context management
ip route 0.0.0.0/0 10.244.137.225
vpc domain 100
peer-keepalive destination 10.244.137.228
interface port-channel1
switchport mode trunk
spanning-tree port type network
speed 1000
vpc peer-link
interface Ethernet1/1
description asa-1-pri gi0/0
switchport access vlan 50
speed 1000
interface Ethernet1/2
description asa-1-pri gi0/1
speed 1000
interface Ethernet1/3
description asa-1-pri gi0/2
switchport access vlan 10
speed 1000
interface Ethernet1/4
description asa-1-pri gi0/3
switchport access vlan 99
speed 1000
interface Ethernet1/5
description asa-1-pri mgmt
speed 1000
interface Ethernet1/6
description ch2-lb-1 eth0/1
shutdown
switchport access vlan 10
speed 1000
interface Ethernet1/7
description ch2-lb-1 eth0/2
shutdown
switchport access vlan 11
speed 1000
interface Ethernet1/8
description ch2-lb-1 mgmt
switchport access vlan 99
speed 1000
interface Ethernet1/9
description Internet
switchport access vlan 50
speed 1000
interface Ethernet1/10
description Temp-Switch
switchport access vlan 50
speed 1000
interface Ethernet1/11
description nx2 mgmt port
switchport access vlan 99
spanning-tree port type edge
speed 1000
interface Ethernet1/23
description temp-pc-access
switchport access vlan 99
speed 1000
interface Ethernet1/24
description ch2-ucs01 mgmt
switchport access vlan 99
speed 1000
interface Ethernet1/25
description ch2-netapp-1 E0E
speed 1000
interface Ethernet1/26
description ch2-netapp-1 mgmt
switchport access vlan 99
speed 1000
interface Ethernet1/27
description ch2-netapp-1 E0C
interface Ethernet1/28
description ch2-netapp-2 E0C
interface Ethernet1/29
description ch2-ucs-1 Po29
interface Ethernet1/30
description ch2-ucs-2 Po30
interface Ethernet1/31
description ch2-nx-2 eth1/31
switchport mode trunk
speed 1000
channel-group 1 mode active
interface Ethernet1/32
description ch2-nx-2 eth1/32
switchport mode trunk
speed 1000
channel-group 1 mode active
interface mgmt0
description mgmt int to nx-2 eth 1/11
vrf member management
ip address 10.244.137.227/27
nx2
cfs eth distribute
feature lacp
feature vpc
feature lldp
feature vtp
spanning-tree vlan 1-100 priority 28672
vrf context management
ip route 0.0.0.0/0 10.244.137.225
vpc domain 100
peer-keepalive destination 10.244.137.227
interface port-channel1
switchport mode trunk
spanning-tree port type network
speed 1000
vpc peer-link
interface Ethernet1/1
description asa-1-sec gi 0/0
switchport access vlan 50
speed 1000
interface Ethernet1/2
description asa-1-sec gi 0/1
speed 1000
interface Ethernet1/3
description asa-1-sec gi 0/2
switchport access vlan 10
speed 1000
interface Ethernet1/4
description asa-1-sec gi 0/3
switchport access vlan 99
speed 1000
interface Ethernet1/5
description asa-1-sec mgmt
shutdown
switchport access vlan 99
speed 1000
interface Ethernet1/6
description ch2-lb-2 eth0/1
shutdown
switchport access vlan 10
speed 1000
interface Ethernet1/7
description ch2-lb-2 eth0/2
shutdown
switchport access vlan 11
speed 1000
interface Ethernet1/8
description ch2-lb-2 mgmt
switchport access vlan 99
speed 1000
interface Ethernet1/11
description dc5-nx-1 mgmt 0
switchport access vlan 99
spanning-tree port type edge
speed 1000
interface Ethernet1/23
description temp-pc-link
switchport access vlan 99
speed 1000
interface Ethernet1/24
description ch2-ucs-2 mgmt
switchport access vlan 99
speed 1000
interface Ethernet1/25
description ch2-netapp-2 E0E
speed 1000
interface Ethernet1/26
description ch2-netapp-2 mgmt
switchport access vlan 99
speed 1000
interface Ethernet1/27
description ch2-netapp-1 E0D
interface Ethernet1/28
description ch2-netapp-2 E0D
interface Ethernet1/29
description ch2-ucs-2 Po29
interface Ethernet1/30
description ch2-ucs-1 Po30
interface Ethernet1/31
description ch2-nx-1 eth 1/31
switchport mode trunk
speed 1000
channel-group 1 mode active
interface Ethernet1/32
description ch2-nx-2 eth 1/32
switchport mode trunk
speed 1000
channel-group 1 mode active
interface mgmt0
description mgmt int to nx-1 eth 1/11
vrf member management
ip address 10.244.137.228/27
nx-1# sho spanning-tree int port-channel 1
No spanning tree information available for port-channel1
nx-1# sho vpc brief
Legend:
(*) - local vPC is down, forwarding via vPC peer-link
vPC domain id : 100
Peer status : peer link is down
vPC keep-alive status : peer is not reachable through peer-keepalive
Configuration consistency status : failed
Per-vlan consistency status : success
Configuration inconsistency reason: Consistency Check Not Performed
Type-2 consistency status : failed
Type-2 inconsistency reason : QoSMgr type-1 configuration incompatible
vPC role : none established
Number of vPCs configured : 0
Peer Gateway : Disabled
Dual-active excluded VLANs : -
Graceful Consistency Check : Disabled (due to peer configuration)
Auto-recovery status : Disabled
vPC Peer-link status
---------------------------------------------------------------------
id Port Status Active vlans
-- ---- ------ --------------------------------------------------
1 Po1 up -
Once again, I have this same configuration running on another set with no issue.
Any suggestions would be appreciated.
Solved! Go to Solution.
12-16-2015 12:13 PM
Cisco recommendation is below
We recommend that you configure the vPC peer-keepalive link on the Cisco Nexus 5000 Series switch to run in the management VRF using the mgmt 0 interfaces. If you configure the default VRF, ensure that the vPC peer link is not used to carry the vPC peer-keepalive messages.
www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/layer2/b_Cisco_Nexus_5000_Series_NX-OS_/Cisco_Nexus_5000_Series_NX-OS__chapter8.html
Why is it working in your existing setup could be for the following reason
1. When you build the vpc most likely the mgmt0 vlan was not on the peer link. Once the VPC is up then you can move the mgmt0 vlan to the vpc peer link and it will work since all we are doing is exchanging the keepalive messages on the peer link. The peer link does not go down when the peer keepalive is lost once vpc is established.
I would recommend you to change this design on your existing setup as you may see a issue if for any reason both 5k reboots at the same time say during a power outage.
-Raj
12-16-2015 11:28 AM
Couple of things-
1. I don't see the peer keep alive up between the peers
vPC keep-alive status : peer is not reachable through peer-keepalive
2. Are you also doing the config on your peer by enabling "vpc peer link" on the other side as well? make sure you do that as well.
-Raj
12-16-2015 11:35 AM
1. Correct, the keep-alive fails and I can't ping the other side. If I remove the vpc peer link command from both switches, I'm able to ping across and spanning-tree restores for that plan.
2. Yes, both switches have vpc peer-link configured on the port channel
Tx
12-16-2015 11:47 AM
How is your mgmt0 connected to each other between the VPC peers? Are they using a vlan which is a vpc vlan that gets suspended when you bring up the peer link?
If so can you have the mgmt0 connected to a non vpc vlan that stays up keeping the keepalive in play. Once the peer keep alive stays up then we can see if po1 will have the vlan forwarding.
-Raj
12-16-2015 12:04 PM
Raj,
My mgmt0 interface was on a Vlan that was being trunked via the port channel that is the peer link. I removed that vlan from the trunk and setup a separate interface to trunk that Vlan. This did bring up the peer-link for vpc between the switches, but what puzzles me is that I have the above configuration on another set of switches w/ no issues.
Tx
12-16-2015 12:13 PM
Cisco recommendation is below
We recommend that you configure the vPC peer-keepalive link on the Cisco Nexus 5000 Series switch to run in the management VRF using the mgmt 0 interfaces. If you configure the default VRF, ensure that the vPC peer link is not used to carry the vPC peer-keepalive messages.
www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/layer2/b_Cisco_Nexus_5000_Series_NX-OS_/Cisco_Nexus_5000_Series_NX-OS__chapter8.html
Why is it working in your existing setup could be for the following reason
1. When you build the vpc most likely the mgmt0 vlan was not on the peer link. Once the VPC is up then you can move the mgmt0 vlan to the vpc peer link and it will work since all we are doing is exchanging the keepalive messages on the peer link. The peer link does not go down when the peer keepalive is lost once vpc is established.
I would recommend you to change this design on your existing setup as you may see a issue if for any reason both 5k reboots at the same time say during a power outage.
-Raj
12-16-2015 12:41 PM
Tx for your assistance!
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