Interface Line Protocol Flapping withtin LACP/Pagp Etherchannel

[moritz.orphall]

Hello there,

suddenly some TenGigabitEthernet interfaces on an uplink of an access switch (C9200l-48P-4X ver. 17.3.4b) begin to flap, which means that the line protocol goes down and up again after approx. 2 seconds. The uplink leads towards an distrubition router (C9500). Those interfaces operate in an etherchannel of 2 links.

When removing interfaces from the etherchannel and let them operate as standalone, the flapping stops immediately. Thats why I would exclude a layer 1 problem like a faulty patch cable, bad gbic etc.... 

We have almost no input errors/CRC on counted on the concerning interfaces. 

The log does not give any more information about possible causes:

021047: Jun  7 09:13:14 CEST: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/0/19, changed state to down

021048: Jun  7 09:13:16 CEST: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/0/19, changed state to up

021049: Jun  7 09:13:56 CEST: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/0/19, changed state to down

021050: Jun  7 09:13:57 CEST: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/0/19, changed state to up

I would be thankful for every help. 

[marce1000]

  - Further look into software version(s) on both devices , use advisory release and or upgrade , if applicable and feasible. For such problems it is always to be better on either latest or latest-advisory version.

 M.

[MHM Cisco World]

are this Issue still not solve ? if yes please can you share the output 

show platform hardware fed qos queue config interface xxx

for both the PO and member port.

[moritz.orphall]

Member Port:

#show platform hardware fed switch active qos queue config interface t2/1/2
Asic:0 Core:0 DATA Port:1 GPN:814 LinkSpeed:0x1
AFD:Disabled FlatAFD:Disabled QoSMap:0 HW Queues: 8 - 15
DrainFast:Disabled PortSoftStart:2 - 732
DTS Hardmax Softmax PortSMin GlblSMin PortStEnd QEnable
----- -------- -------- -------- -------- --------- -------
0 1 6 81 7 324 31 313 0 0 3 976 En
1 1 5 0 8 488 31 472 8 122 3 976 En
2 1 5 0 6 0 0 0 0 0 3 976 En
3 1 5 0 6 0 0 0 0 0 3 976 En
4 1 5 0 6 0 0 0 0 0 3 976 En
5 1 5 0 6 0 0 0 0 0 3 976 En
6 1 5 0 6 0 0 0 0 0 3 976 En
7 1 5 0 6 0 0 0 0 0 3 976 En
Priority Shaped/shared weight shaping_step sharpedWeight
-------- ------------- ------ ------------ -------------
0 0 Shared 50 0 0
1 0 Shared 75 0 0
2 0 Shared 10000 0 0
3 0 Shared 10000 0 0
4 0 Shared 10000 0 0
5 0 Shared 10000 0 0
6 0 Shared 10000 0 0
7 0 Shared 10000 0 0
Port Port Port Port
Priority Shaped/shared weight shaping_step
-------- ------------- ------ ------------
2 Shaped 254 255

Weight0 Max_Th0 Min_Th0 Weigth1 Max_Th1 Min_Th1 Weight2 Max_Th2 Min_Th2
------- ------- ------- ------- ------- ------- ------- ------- ------
0 0 322 0 0 360 0 0 405 0
1 0 388 0 0 434 0 0 488 0
2 0 0 0 0 0 0 0 0 0
3 0 0 0 0 0 0 0 0 0
4 0 0 0 0 0 0 0 0 0
5 0 0 0 0 0 0 0 0 0
6 0 0 0 0 0 0 0 0 0
7 0 0 0 0 0 0 0 0 0

port-channel: 

show platform hardware fed switch active qos queue config interface po6
Interface Port-channel6 not found, err 18 

-->Interface po6 still exists, dont know what this error means 

[MHM Cisco World]

the issue as I see is QoS misconfig, 
first the LACP is priority is 0 or 1 since it is management traffic, BUT the weight compare to other Queue is so low 
25 or 75 compare to 10000

so there is drop in management interface include LACP and this make port flapping.
try increase the weight to be 10000 and see if the port is stable.

[balaji.bandi]

why there is a mismatch config, po4 vs Po6 on the interface config. is this config of TenGigabitEthernet1/0/19 ?

what interface other side router side?  The interface of Distribution Router (what router ?) 

[moritz.orphall]

T2/1/2 is the interface of the access switch (C9200l) and t1/0/19 is the interface on the side of the link on a distribution router (C9500)

They are bundled in po6, so there is no port channel mismatch.

[balaji.bandi]

We lost track of this thread  to be honestly -

Let me ask you again to get clarity of the problem

1. One side Cat 9500 Switch ( is this SVL ?)

2. Another side Cat 9200 Switch ( is this stack switch or single ?)

3. you try to build port-channel  - using how many ports 1 port or more than 1 port ?

4. what SFP Module is this ?

5. what patch cable you using Multi mode or single mode ?

From Cat 9200 post below information :

1. show interface te x/x  ( all the ports in port-channel)

2. show etherchannel 6 summary

From Cat 9300 post below information :

1. show interface te x/x  ( all the ports in port-channel)

2. show etherchannel 6 summary