N4k Link State Tracking with two upstream port-channels

[yenaungoo]

Hi

Topology is with 1 pair of N5k and 1 pair of N4k. In between, there are LAN and FCOE links with separate port-chanels. My customer want to configure linkstate on N4k for both LAN & FCOE upstream links. If one of the port-channels (LAN or FCOE) were down, they want all the server facing downstream ports to be down.

Currently only LAN links are with link state. If we also configure for FCOE link with the same upstream group as LAN, what would happen from below (1 or 2)?

1) all associated downstream ports become error-disabled state when both LAN & FCOE upstream port-channels were down

2) all associated downstream ports become error-disabled state when either LAN or FCOE upstream port-channel were down

If no-1 is correct, is there any solution to be able to track these LAN & FCOE links at the same time?

Ref: http://www.cisco.com/en/US/docs/switches/datacenter/nexus4000/nexus4000_i/sw/configuration/guide/rel_4_1_2_E1_1/link_state_track.html

Thanks in advance,

Ye

[Prashanth Krishnappa]

Ye

You cannot configure your LAN and FCoE port-channels with same LST group. The CLI will give you an error like this

N4k-Top# sh run int port-channel 100

version 4.1(2)E1(1h)

interface port-channel100

  description to aipv6lab-r5000

  switchport mode trunk

  fip-snooping port-mode fcf

  link state group 1 upstream

  speed 10000

N4k-Top# sh run int port-channel 411

version 4.1(2)E1(1h)

interface port-channel411

  description ***LAN***

  switchport mode trunk

  speed 10000

N4k-Top# conf

Enter configuration commands, one per line.  End with CNTL/Z.

N4k-Top(config)# interface port-channel411

N4k-Top(config-if)#   link state group 1 upstream

ERROR: Error on interface port-channel411: interface is a member of another group

[yenaungoo]

Hi So it means we can only configure linkstate upstream for one port-channel (either LAN or FCOE link).

Cisco document didn't mention this limitation. Thank you so much for your help.

Ye

[Surya ARBY]

The best design with LST is to consolidate all the traffic into a single port-channel (data+FCoE) and use straight through architecture to a singl parent switch.

[sbhadrav@cisco.com]

To configure a link-state group and to assign an interface to a group, perform this task beginning in
privileged EXEC mode:
Step 1 Switch# configure terminal Enters global configuration mode.
Step 2 Switch(config)# link state track number Creates a link-state group, and enable link-state tracking. The
group number can be 1 to 10; the default is 1.
Step 3 Switch(config)# interface interface-id Specifies a physical interface or range of interfaces to configure,
and enters interface configuration mode.
Valid interfaces include switch ports in access or trunk mode
(IEEE 802.1q), routed ports, or multiple ports bundled into an
EtherChannel interface (static or LACP), also in trunk mode.
Step 4 Switch(config-if)# link state group
This example shows how to create a link-state group and configure the interfaces:
Switch# configure terminal
Switch(config)# link state track 1
Switch(config)# interface gigabitethernet3/1
Switch(config-if)# link state group 1 upstream
Switch(config-if)# interface gigabitethernet3/3
Switch(config-if)# link state group 1 upstream
Switch(config-if)# interface gigabitethernet3/5
Switch(config-if)# link state group 1 downstream
Switch(config-if)# interface gigabitethernet3/7
Switch(config-if)# link state group 1 downstream
Switch(config-if)# end
To disable a link-state group, use the no link state track number global configuration command.
[number] {upstream | downstream}
Specifies a link-state group, and configure the interface as either
an upstream or downstream interface in the group.The group
number can be 1 to 10; the default is 1.
Step 5 Switch(config-if)# end Returns to privileged EXEC mode.
Step 6 Switch# show running-config Verifies your entries.
Step 7 Switch# copy running-config startup-config (Optional) Saves your entries in the configuration file.
To display the link-state group information, enter the show link state group command. Enter this
command without keywords to display information about all link-state groups.
Enter the group number to display information specific to the group. Enter the detail keyword to display
detailed information about the group.
it is an example of output from the show link state group 1 command:
Switch> show link state group 1
Link State Group: 1 Status: Enabled, Down
it is an example of output from the show link state group detail command:
Switch> show link state group detail
(Up):Interface up (Dwn):Interface Down (Dis):Interface disabled
Link State Group: 1 Status: Enabled, Down
Upstream Interfaces : Gi3/5(Dwn) Gi3/6(Dwn)
Downstream Interfaces : Gi3/1(Dis) Gi3/2(Dis) Gi3/3(Dis) Gi3/4(Dis)
Link State Group: 2 Status: Enabled, Down
Upstream Interfaces : Gi3/15(Dwn) Gi3/16(Dwn) Gi3/17(Dwn)
Downstream Interfaces : Gi3/11(Dis) Gi3/12(Dis) Gi3/13(Dis) Gi3/14(Dis)
(Up):Interface up (Dwn):Interface Down (Dis):Interface disabled