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Contributor
Posts: 35
Registered: ‎06-21-2011
Accepted Solution

Creating ISL trunk between gen4 DCX and gen6 DCX - problems!

Hi all,

 

We are experiencing problems trying to form ISLs between a gen4 and a gen6 DCX.

 

When we enable the ports on both switches, we see enc_out count going up in millions on both sides on the ISL on one link and on the other it also goes up but at a slower rate. The trunk will form but this enc_out counter is not good. Config of ports:

 

DCX gen4:

 

Area Number:              169
Speed Level:              8G
Fill Word(On Active)      0(Idle-Idle)
Fill Word(Current)        0(Idle-Idle)
AL_PA Offset 13:          OFF
Trunk Port                ON
Long Distance             OFF
VC Link Init              OFF
Locked L_Port             OFF
Locked G_Port             OFF
Disabled E_Port           OFF
Locked E_Port             OFF
ISL R_RDY Mode            OFF
RSCN Suppressed           OFF
Persistent Disable        OFF
LOS TOV mode              0(OFF)
NPIV capability           ON
QOS Port                  AE
Port Auto Disable:        OFF
Rate Limit                OFF
EX Port                   OFF
Mirror Port               OFF
SIM Port                  OFF
Credit Recovery           ON
F_Port Buffers            OFF
E_Port Credits            OFF
Fault Delay:              0(R_A_TOV)
NPIV PP Limit:            126
NPIV FLOGI Logout:        OFF
CSCTL mode:               OFF
TDZ mode:                 OFF

 

DCX gen6:

 

Area Number:              157
Octet Speed Combo:        1(32G|16G|8G|4G)
Speed Level:              8G
AL_PA Offset 13:          OFF
Trunk Port                ON
Long Distance             OFF
VC Link Init              OFF
Locked L_Port             OFF
Locked G_Port             OFF
Disabled E_Port           OFF
Locked E_Port             OFF
ISL R_RDY Mode            OFF
RSCN Suppressed           OFF
Persistent Disable        OFF
LOS TOV mode              0(OFF)
NPIV capability           ON
QOS Port                  AE
Port Auto Disable:        OFF
EX Port                   OFF
Mirror Port               OFF
SIM Port                  OFF
Credit Recovery           ON
F_Port Buffers            OFF
E_Port Credits            OFF
Fault Delay:              0(R_A_TOV)
NPIV PP Limit:            126
NPIV FLOGI Logout:        OFF
CSCTL mode:               OFF
TDZ mode:                 OFF
D-Port mode:              OFF
D-Port over DWDM:         OFF
Compression:              OFF
Encryption:               OFF
10G/16G FEC:              ON
16G FEC via TTS:            OFF

 

Furthermore we note a very low RX power (sub 50uW) on both ends on both trunk ports.

 

RX Power:    -13.7   dBm (42.2 uW)

TX Power:    -2.6    dBm (545.5 uW)

 

My first concern is the cables, but we are having them tested. If the cables come back okay, is there something else that could be an issue? Do the configs look okay on the ports?

 

Thanks for reading, hope someone can help!

 

Frequent Contributor
Posts: 124
Registered: ‎03-20-2018

Re: Creating ISL trunk between gen4 DCX and gen6 DCX - problems!

[ Edited ]

ENC_OUT coupled with low RX Power usually indicates a cable issue.

 

There are many factors that could be in play here.

 

Essentially, this is a drop in signal. (Decibel drop)

 

Distance could be a factor. Exceeding bend radius could be a factor. Pinched cables could be a factor. The number of connections between switch 1 and switch 2 could be a factor. (Cable panels). Dirty optics could be a factor.

 

 

Frequent Contributor
Posts: 124
Registered: ‎03-20-2018

Re: Creating ISL trunk between gen4 DCX and gen6 DCX - problems!

On your Gen4 switch, you might consider setting fillword to 3. Though, this usually doesn't effect RX Power.

Contributor
Posts: 35
Registered: ‎06-21-2011

Re: Creating ISL trunk between gen4 DCX and gen6 DCX - problems!

Hi,

We are having the cables checked out today.
I also think the issue points towards damaged cables. Length of cables are between 80-100 metres.

Thanks for your information :-)
Contributor
Posts: 35
Registered: ‎06-21-2011

Re: Creating ISL trunk between gen4 DCX and gen6 DCX - problems!

On the Gen 6 you cannot change the fillword settings.

 

Is 3 definitely the correct value? I thought this parameter was related to invalid fillwords.

Frequent Contributor
Posts: 87
Registered: ‎01-19-2018

Re: Creating ISL trunk between gen4 DCX and gen6 DCX - problems!

I'd even set the fillword to 2.

 

Did you specifically set the VC Link Init to OFF? How big is the distance between the switches? What kind of equipment do you have in the middle? Do you have a proper combination of single mode and multi mode cables/connectors?

Contributor
Posts: 35
Registered: ‎06-21-2011

Re: Creating ISL trunk between gen4 DCX and gen6 DCX - problems!

I did not change the VC Link init off value, it is default. The distance is 100m. I am not sure of the existence of patch panels or what lies in between them. The cables are multimode OM-3.
Frequent Contributor
Posts: 124
Registered: ‎03-20-2018

Re: Creating ISL trunk between gen4 DCX and gen6 DCX - problems!

On Gen5/6, fillword is automatic. On Gen4, fillword is dependent on what is attached. Some vendors require a 2. As @Alexey Stepanov said, a fillword of 2 could work as well. I would set to 3.

Contributor
Posts: 35
Registered: ‎06-21-2011

Re: Creating ISL trunk between gen4 DCX and gen6 DCX - problems!

I don't think the fillword values are causing the enc_out counter to increment. We did change these values to 3 as you mentioned and the errors did not stop going up.


@ussenterprise-bda wrote:

On Gen5/6, fillword is automatic. On Gen4, fillword is dependent on what is attached. Some vendors require a 2. As @Alexey Stepanov said, a fillword of 2 could work as well. I would set to 3.


 

Frequent Contributor
Posts: 124
Registered: ‎03-20-2018

Re: Creating ISL trunk between gen4 DCX and gen6 DCX - problems!

They are most likely not causing ENC_OUT errors.

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