Switch ports connected to Netapp FAS2020 flapping continuosly

[hemadri37]

Dear All,

I am facing an issue of continuous port flap.

There is one NETAPP FAS2020 2U connected to the cisco switches.

Port 1/8 of cisco switch A is connected to EOA in module A and port 1/8 of cisco switch B is connected to EOB in module A.

port 1/8 in both cisco switches is flapping continuosly. logs and existing configuration is attached.

please advise.

Attachment: 

netapp.docx

These ports in both cisco switches are flapping continuosly.

2716783: Feb  1 08:22:59: %DTP-5-NONTRUNKPORTON: Port Gi1/8 has become non-trunk
2716784: Feb  1 08:23:00: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/8, changed state to down
2716785: Feb  1 08:23:01: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to down
2716786: Feb  1 08:23:03: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to up
2716787: Feb  1 08:23:05: %DTP-5-TRUNKPORTON: Port Gi1/8 has become dot1q trunk
2716788: Feb  1 08:23:05: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/8, changed state to up
2716789: Feb  1 08:23:07: %DTP-5-NONTRUNKPORTON: Port Gi1/8 has become non-trunk
2716790: Feb  1 08:23:08: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/8, changed state to down
2716791: Feb  1 08:23:09: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to down
2716792: Feb  1 08:23:12: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to up
2716793: Feb  1 08:23:14: %DTP-5-TRUNKPORTON: Port Gi1/8 has become dot1q trunk
2716794: Feb  1 08:23:14: %DTP-5-NONTRUNKPORTON: Port Gi1/8 has become non-trunk
2716795: Feb  1 08:23:16: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to down
2716796: Feb  1 08:23:19: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to up
2716797: Feb  1 08:23:21: %DTP-5-TRUNKPORTON: Port Gi1/8 has become dot1q trunk
2716798: Feb  1 08:23:21: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/8, changed state to up
2716799: Feb  1 08:23:50: %SPANTREE-5-TOPOTRAP: Topology Change Trap for vlan 200
2716800: Feb  1 08:24:10: %DTP-5-NONTRUNKPORTON: Port Gi1/8 has become non-trunk

[Mark Malone]

Hi

Looks like you having an STP issue , set both ports as portfast trunk on the switches going back to the server and then set one of the links with an stp cost of 1000 so it becomes backup link

You cant have 2 links split across 2 switches like that unless there VSS or Nexus VPC , one of your links must be backup , your causing a loop between the switches and server

[hemadri37]

Hi,

Thanks for your reply.

I had already given portfast command. following is the config of both interfaces in switches.

interface GigabitEthernet1/8
description CSU-RAID-MMS1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 200-202
switchport mode trunk
logging event link-status
logging event trunk-status
storm-control broadcast level 1.00
storm-control action trap
spanningtree-portfast
end

problem not solved.

[Mark Malone]

Hi

should be portfast trunk is that available ?  you have the port set to trunk , not set as access portfast

Then add spanning-tree cost to one of the ports so it becomes backup in stp

spanning-tree cost 1000

[hemadri37]

Hi,

Portfast trunk is not there. will set to portfast trunk.

can it alone solve the problem or I need to specify the cost also.

In many cases in our NW we didnot specify cost , all are working fine except this issue.

can we suspect any NIC related issue with server.

[Mark Malone]

Hi

the stp command is the fix as it puts the link into blocking state , but if the other link ever fails it will automatically take over , but it needs to be on one of the interfaces to make it less preferred to prevent a loop occurring due to the physical setup

Its not your server its because its dual linked to 2 switches at layer 2 and the traffic is  looping between them and the server

The other option is use a flex link setup again though you have one primary and one backup link , you cant have 2 active links setup that  way going to 2 separate switches

You could port-channel the links to one switch for resiliency but not both unless vss or vpc capable

[hemadri37]

Hi,

Thanks a lot for your valuable inputs.

I will update once implemented.

[paul driver]

Hello

Just like to add, I would suggest to turn DTP off also as it is indeed still active on those switchports especially if your wanting to hardcode to trunking mode anyway.

int x/x
switchport nonegotiate

res
Paul

[hemadri37]

Hi all,

For understanding i will explain the scenario with diagram.

There is one NETAPP FAS2020 2U connected to the cisco switches.

Port 1/8 of cisco switch A is connected to EOA in module A and port 1/8 of cisco switch B is connected to EOB in module A.

port 1/8 in both cisco switches is flapping continuosly. logs and existing configuration is attached in starting point of discussion.

please advise.

Thanks

Hemadri

[hemadri37]

Dear members,

I suspected issue with Netapp side.

Thanks

Hemadri

[hemadri37]

Dear All,

can anyone share your views please as Issue still not resolved.

Thanks

Hemadri

[pwwiddicombe]

This may not actually be a VLAN/STP issue at all.  How is the Netapp configured for the 2 interfaces?  Are they for failover or for performance?

If for performance, both links should go to the same switch, and you create an Etherchannel on the switch (but the configuration has to match the Netapp - read their design guides !).

If for failover, again the netapp has to know about it, and only use one link  unless it fails, in which case it flips over to the other.  In that case the connections can be to 2 separate switches.

However, if the netapp is set to performance and assumes a trunk, it will send packets on both links; and the non-bundled cisco ports think you are moving the netapp from one port to the other continuously - and don't like it, and report flapping.

[hemadri37]

Hi,

NETAPP FAS2020 2U is connected to the switches. Two links from netapp are connected to two different switches 1 and 2. port is Gi 1/8 in both siwtches. Both ports are configured as trunk ports. it is for failover.

Logs of the switch attached below. in both switches port gi1/8 is flapping continuously and changing STP states.

Attachment: 

netapp.docx

These ports in both cisco switches are flapping continuosly.

2716783: Feb  1 08:22:59: %DTP-5-NONTRUNKPORTON: Port Gi1/8 has become non-trunk
2716784: Feb  1 08:23:00: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/8, changed state to down
2716785: Feb  1 08:23:01: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to down
2716786: Feb  1 08:23:03: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to up
2716787: Feb  1 08:23:05: %DTP-5-TRUNKPORTON: Port Gi1/8 has become dot1q trunk
2716788: Feb  1 08:23:05: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/8, changed state to up
2716789: Feb  1 08:23:07: %DTP-5-NONTRUNKPORTON: Port Gi1/8 has become non-trunk
2716790: Feb  1 08:23:08: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/8, changed state to down
2716791: Feb  1 08:23:09: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to down
2716792: Feb  1 08:23:12: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to up
2716793: Feb  1 08:23:14: %DTP-5-TRUNKPORTON: Port Gi1/8 has become dot1q trunk
2716794: Feb  1 08:23:14: %DTP-5-NONTRUNKPORTON: Port Gi1/8 has become non-trunk
2716795: Feb  1 08:23:16: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to down
2716796: Feb  1 08:23:19: %LINK-3-UPDOWN: Interface GigabitEthernet1/8, changed state to up
2716797: Feb  1 08:23:21: %DTP-5-TRUNKPORTON: Port Gi1/8 has become dot1q trunk
2716798: Feb  1 08:23:21: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/8, changed state to up
2716799: Feb  1 08:23:50: %SPANTREE-5-TOPOTRAP: Topology Change Trap for vlan 200
2716800: Feb  1 08:24:10: %DTP-5-NONTRUNKPORTON: Port Gi1/8 has become non-trunk

Thanks

Hemadri

[pwwiddicombe]

Is there a way we can see the configuration of the Netapp?  when one link is up in failover mode, the other should be "quiet" and not talking - which doesn't seem to be the case.    Since you have 3 vlans trunked, are all 3 configured the same way on the Netapp?

I think what you want is called a "Single mode interface group" on the OnTap side, and minimal configuration necessary on the Cisco side - unless you are trying to use iSCSI and the "public / user" capabilities on the same NIC on the Netapp.

[hemadri37]

hi,

Following is the configuration of Netapp side.

csu1a*> vif status
default: transmit 'IP Load balancing', VIF Type 'multi_mode', fail 'log'
vif0: 1 link, transmit 'none', VIF Type 'single_mode' fail 'default'
     VIF Status    Up     Addr_set
    up:
        e0a: state up, since 28Sep2016 16:06:25 (159+22:16:08)
                mediatype: auto-1000t-fd-up
                flags: enabled favored
                input packets 68944474508, input bytes 33876148175829
                output packets 94779323131, output bytes 118910514473679
                output probe packets 0, input probe packets 0
                strike count: 0 of 10
                up indications 2, broken indications 1
                drops (if) 0, drops (link) 0
                indication: up at 28Sep2016 16:06:25
                        consecutive 13822172, transitions 3
    down:
        e0b: state down, since 28Sep2016 16:06:25 (159+22:16:08)
                mediatype: auto-1000t-fd-up
                flags: enabled
                input packets 126, input bytes 900248256
                output packets 0, output bytes 0
                output probe packets 0, input probe packets 0
                strike count: 0 of 10
                up indications 2, broken indications 1
                drops (if) 0, drops (link) 0
                indication: up at 28Sep2016 16:06:25
                        consecutive 13822172, transitions 3
 

please advise whether any issue with Netapp config or Switch config.

how to proceed further