N5K vPC Keepalive link and management concerns

[Nicholas Poole]

I need help with the concept of the vPC keepalive link.  I am trying to get my head round some configs before the kit turns up which is on order...

I have seen a Cisco doc that says you can use an SVI for the keepalive link on the N5K, but how do you do that as I though the N5K was a L2 switch and the command references I have searched through dont show a the command: interface vlan x

Basically I am trying to work out how to manage this switch remotely and and get the Keepalive operational, but I dont have a separate dedicated management LAN to use (who does these days?).  So if I have to use an SVI, that means it runs on a VLAN, which will have to cross the vPC PeerLink, and this I thought was a fundamental no-no of the vPC design rules: dont send the keepalive across the peerlink.

On the N7K I will use a dedicated L3 point-to-point fibre interface for the Keepalive as a I dont have a management LAN, so that seems easy enough, yes/no?

Thanks for any explanation attempts in advance...

[Ganesh Hariharan]

I need help with the concept of
the vPC keepalive link.  I am trying to get my head round some configs
before the kit turns up which is on order...
I
have seen a Cisco doc that says you can use an SVI for the keepalive
link on the N5K, but how do you do that as I though the N5K was a L2
switch and the command references I have searched through dont show a
the command: interface vlan x
Basically
I am trying to work out how to manage this switch remotely and and get
the Keepalive operational, but I dont have a separate dedicated
management LAN to use (who does these days?).  So if I have to use an
SVI, that means it runs on a VLAN, which will have to cross the vPC
PeerLink, and this I thought was a fundamental no-no of the vPC design
rules: dont send the keepalive across the peerlink.
On
the N7K I will use a dedicated L3 point-to-point fibre interface for
the Keepalive as a I dont have a management LAN, so that seems easy
enough, yes/no?
Thanks for any explanation attempts in advance...

Hi,

Check out the below link for vpc configuration on nexus 5k hope that helps.

http://jasonnash.wordpress.com/2009/08/10/vpc-virtual-port-channel-and-the-nexus-platform/

Ganesh.H

If helpful do rate the post

[Nicholas Poole]

Thanks for posting but your blog doesnt answer my concern.  Your post shows using the mgmt0 port, which I know is what you can do, but without a seperate dedicated management LAN infrastructure how can I use it?  If I just put a xover cable between them then I cant remotely connect to the switch as the IP addresses are on a private wire only.  Im looking for an example of how to use an SVI instead of the mgmt0 interface, thanks.

[selhassbaoui]

Hello,

you still need the answer or you solved this issue?

[Nicholas Poole]

still looking for more info

[selhassbaoui]

Hi,

I worked on the same thing last Week, and to separate The peer Link and the keepalive link:

Commun Config
feature interface-vlan feature lacp feature vpc feature fex

  - I used one link 10Gig as trunk  with a dedicated Intervace VLAN  for a KeepAlive.

keepAlive Config

------------------config for 1st N5K-------------------------------- vlan 900 name VLAN-KeepAlive exit ! interface Vlan900   ip address 192.168.250.5/30   no shutdown ! vpc domain 10 peer-keepalive destination 192.168.250.6 source 192.168.250.5 vrf default exit ! interface Ethernet1/33 description To-5020-RDC-132-Eth1/33-KeepAlive switchport mode trunk switchport trunk allowed vlan 900 no shut exit ! ------------------config for 2nd N5K-------------------------------- vlan 900 name VLAN-KeepAlive   exit ! interface Vlan900    ip address 192.168.250.6/30   no shutdown ! vpc domain 10   peer-keepalive destination 192.168.250.5 source 192.168.250.6 vrf default   exit ! interface Ethernet1/33   description To-5020-RDC-131-Eth1/33-KeepAlive   switchport mode trunk   switchport trunk allowed vlan 900   no shut   exit !

  - Two links 10Gig bundled in a portchannel on each N5K for pee link

Peer Link Config

------------------config for 1st N5K-------------------------------- interface port-channel10   description To-5020-RDC-132-vPCpeer   switchport mode trunk   switchport trunk allowed vlan 1   vpc peer-link   spanning-tree port type network   no shut ! interface Ethernet1/35   description To-5020-RDC-132-Eth1/35   switchport mode trunk   switchport trunk allowed vlan 1   channel-group 10 mode active   no shut   exit ! interface Ethernet1/36   description To-5020-RDC-132-Eth1/36   switchport mode trunk   switchport trunk allowed vlan 1   channel-group 10 mode active   no shut   exit ! ------------------config for 2nd N5K-------------------------------- interface port-channel10    description To-5020-RDC-131-vPCpeer    switchport mode trunk    switchport trunk allowed vlan 1    vpc peer-link    spanning-tree port type network    no shut ! interface Ethernet1/35    description To-5020-RDC-131-Eth1/35    switchport mode trunk    switchport trunk allowed vlan 1    channel-group 10 mode active    no shut    exit ! interface Ethernet1/36    description To-5020-RDC-131-Eth1/36    switchport mode trunk    switchport trunk allowed vlan 1    channel-group 10 mode active    no shut    exit   !

I used the interface VLAN 1 for management.

BR;

[ppflaum12]

Do you have to use a seperate svi? Or could you use vlan 1 in your configuration?

[benedict lawrence]

Dear,

There is also some additionnal considerations to set up VPC peer keep-alive with a SVI:

Please find below recommandations from CISCO :

In  an emulated switch setup, inband keepalive does not work. The following  steps are recommended for peer keepalive over SVI when a switch is in  FabricPath mode:

–Use a dedicated front panel port as a vPC+ keepalive. The port should be in CE mode.

–Use a dedicated VLAN to carry the keepalive interface. The VLAN should be CE VLAN.

–Add  the management keyword to the corresponding SVI so that the failure of a  Layer 3 module will not bring down the SVI interface.

–Enter the dual-active exclude interface-vlan keepalive-vlan command to prevent the SVI from going down on the secondary when a peer-link goes down

The "management" keyword have to be applied on the vlan interface (with dedicated VLAN), and  "dual-active" command....

Because else interface VLAN is considered as a common forwarding interface.

Please find below the related link :

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/release/notes/Rel_5_1_3_N2_1/Nexus5000_Release_Notes_5_1_3_N2.html

I hope it will be helpfull,

Best Regards,