Re: Nexus 7k internal l2fm l2dbg output interpretation

GoncaloContente · ‎02-05-2018

Hi, while trying to troubleshoot a mac move, I have run the following command to see if i could get some information about this mac moves:

N7K01-CPDA-CORE1# sh system internal l2fm l2dbg macdb address 5cb9.01eb.d747 vlan 100
Legend
------
Db:  0-MACDB, 1-GWMACDB, 2-SMACDB, 3-RMDB,    4-SECMACDB
Src: 0-UNKNOWN, 1-L2FM, 2-PEER, 3-LC, 4-HSRP
     5-GLBP, 6-VRRP, 7-STP, 8-DOTX, 9-PSEC 10-CLI 11-PVLAN
     12-ETHPM, 13-ALW_LRN, 14-Non_PI_MOD, 15-MCT_DOWN, 16 - SDB
     17-OTV, 18-Debounce Timer, 19-AM, 20-PCM_DOWN, 21 - MCT_UP
     22-L2VPN, 23-EFP, 24-DRV 25-ELTM
Slot:0 based for LCS 19-MCEC 20-OTV/ORIB

 VLAN: 100 MAC: 5cb9.01eb.d747 FE ID: 2
  Time                     If/swid    Db Op                    Src Slot  FE  HW_ADDR Count
    Sun Feb  4 20:52:23 2018 0x1a015000 0  AGE                  3    0    2    0

 VLAN: 100 MAC: 5cb9.01eb.d747
  Time                     If/swid    Db Op                    Src Slot  FE  HW_ADDR Count
    Fri Feb  2 12:59:33 2018 0x1a015000 0  UPDATE               3    0    1    0
    Fri Feb  2 12:59:33 2018 0x1a015000 0  UPDATE               2    19   0    0 1
    Fri Feb  2 12:59:34 2018 0x1a015000 0  UPDATE               3    0    5    0
    Sun Feb  4 20:52:23 2018 0x1a015000 0  DELETE               0    0    15   0
    Mon Feb  5 08:36:44 2018 0xffffffff 0  NOT_FOUND_INS_PC     2    19   0    0
    Mon Feb  5 08:36:44 2018 0xffffffff 0  INSERT               2    19   0    0
    Mon Feb  5 08:36:44 2018 0x1a015000 0  UPDATE               3    0    2    0
    Mon Feb  5 08:39:27 2018 0x1a015000 0  UPDATE               3    0    0    0
    Mon Feb  5 08:39:27 2018 0x1a015000 0  UPDATE               3    0    1    0
    Mon Feb  5 08:39:27 2018 0x1a015000 0  UPDATE               3    0    3    0
    Mon Feb  5 08:39:27 2018 0x1a015000 0  UPDATE               3    0    4    0
    Mon Feb  5 08:39:27 2018 0x1a015000 0  UPDATE               3    0    5    0
    Mon Feb  5 08:39:27 2018 0x1a015000 0  NOT_FOUND_INS_PC     2    19   0    0
    Mon Feb  5 08:39:27 2018 0x1a015000 0  UPDATE               2    19   0    0 1
    Mon Feb  5 08:39:28 2018 0x1a015000 0  UPDATE               2    19   0    0

The If/swid of 0xffffffff is leading me into thinking that there some kind of flooding on the local system but i have no idea why.

Also i would like know if anyone can explain me what is the meaning of NOT_FOUND_INS_PC?

Regards

Gonçalo Reis

Diana Karolina Rojas · ‎02-05-2018

Hello Gonzalo,

When you see a mac address movement it is usually due to some of these causes: L2 loop, Wireless Clients roaming between Access Point, Vmotion or Misconfigured Active/Standby NIC Teaming

Cisco recommend this steps to solve that:

"When this log message is printed, the following steps can be used to track the source of the move:

Document the interfaces which are reporting the mac moving.
Log into the device that attaches to these interfaces and enable mac move notification there if not already enabled.
Follow this logic until you are able to track down the source of the mac move.

Command to enable mac move notification:

N7K/N9K: logging level l2fm 5

These commands are non intrusive and will only print additonal syslog messages pertaining to mac flaps." https://www.cisco.com/c/en/us/support/docs/switches/nexus-7000-series-switches/200424-Nexus-L2FM-4-L2FM-MAC-MOVE-syslog-expla.html

I tried to searh the meaning of this output "NOT_FOUND_INS_PC" but I can not find anything. I hope this anwers can help you to solve the problem.

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Regards,

GoncaloContente · ‎02-05-2018

Hi Diana,

Thank you for replying and for trying to help, the logs on one of the nexus are as follows:

 N7K02-RECT-CORE2 %L2FM-4-L2FM_MAC_MOVE: Mac fcaa.14aa.a1bc in vlan 100 has moved from  100.0.65535 to  100.0.3050

As you can see the mac move is from a non-physical port to a physical port.

If i convert 3050 to hex i get 0x0BEA, then with the command

N7K01-CPDA-CORE1# sh system internal pixm info ltl 0x0bea

Member info
------------------
Type            LTL
---------------------------------
PHY_PORT       Eth1/22

or

N7K01-CPDA-CORE1# sh system internal pixm info | in 0x1a015000
0x0bea 0x1a015000  Eth1/22      2    1

i can see which is the physical port.

Now for the port 100.0.65535, when i convert 65535 to hex, i get ffff, if i look for this port the switch says it is not configured.

N7K01-CPDA-CORE1# sh system internal pixm info ltl 0xffff
0xffff is not configured

or

N7K01-CPDA-CORE1# sh system internal pixm info | in 0xffffffff

I don't know what is this port 100.0.65535 and what is used for, this is what i have been trying to found for the last days. i also have another post about this.

Regards

Gonçalo Reis

Diana Karolina Rojas · ‎02-05-2018

Do you have high CPU use? and do you have port-channels that involve the physical interface Eth1/22?

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Regards,

GoncaloContente · ‎02-05-2018

Hi Diana,

I dont have any of that, the CPU is very low and the interface eth 1/22 is not on a port channel.

Regards

Goncalo Reis