Fibre Channel (SAN)

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Occasional Contributor
Posts: 12
Registered: ‎04-08-2016
Accepted Solution

SFP RX power is low

Hi could anyone of you please help me in getting this understand? and provide the solution.

 

Switch1:admin> portstatsshow 46
stat_wtx                27392576    4-byte words transmitted
stat_wrx                873596      4-byte words received
stat_ftx                79234       Frames transmitted
stat_frx                22034       Frames received
stat_c2_frx             0           Class 2 frames received
stat_c3_frx             22034       Class 3 frames received
stat_lc_rx              0           Link control frames received
stat_mc_rx              0           Multicast frames received
stat_mc_to              0           Multicast timeouts
stat_mc_tx              0           Multicast frames transmitted
tim_rdy_pri             0           Time R_RDY high priority
tim_txcrd_z             65544059    Time TX Credit Zero (2.5Us ticks)
tim_txcrd_z_vc  0- 3:  0           0           0           0
tim_txcrd_z_vc  4- 7:  117486881   0           0           0
tim_txcrd_z_vc  8-11:  0           0           0           0
tim_txcrd_z_vc 12-15:  0           0           0           0
er_enc_in               79          Encoding errors inside of frames
er_crc                  74          Frames with CRC errors
er_trunc                0           Frames shorter than minimum
er_toolong              0           Frames longer than maximum
er_bad_eof              3           Frames with bad end-of-frame
er_enc_out              1287697719  Encoding error outside of frames
er_bad_os               2065937207  Invalid ordered set
er_rx_c3_timeout        0           Class 3 receive frames discarded due to timeout
er_tx_c3_timeout        1637        Class 3 transmit frames discarded due to timeout
er_c3_dest_unreach      0           Class 3 frames discarded due to destination unreachable
er_other_discard        1           Other discards
er_type1_miss           0           frames with FTB type 1 miss
er_type2_miss           0           frames with FTB type 2 miss
er_type6_miss           0           frames with FTB type 6 miss
er_zone_miss            0           frames with hard zoning miss
er_lun_zone_miss        0           frames with LUN zoning miss
er_crc_good_eof         71          Crc error with good eof
er_inv_arb              0           Invalid ARB
open                    0           loop_open
transfer                0           loop_transfer
opened                  0           FL_Port opened
starve_stop             0           tenancies stopped due to starvation
fl_tenancy              0           number of times FL has the tenancy
nl_tenancy              0           number of times NL has the tenancy
zero_tenancy            0           zero tenancy

Please find the above statics of the port46's portstats. And its SFP's RX power is -15.4 the device which is connected to this port is a server's FC port. This server is registered in 2Node IBM-SVC CG8 where this particular WWPN is showing as degraded ( logged in only on one node of SVC) i just wonder how this is able to login to one node of SVC when its RX is -15.4? Still why not its not able to login to another node of SVC?

Brocade Moderator
Posts: 251
Registered: ‎08-31-2009

Re: SFP RX power is low

[ Edited ]

Hello,

 

There are physical layer issues on the link between the Brocade port and the server.

The problem is most likely on the fiber or sfp. SFP need to be checked on server side in priority.

Any and all information provided by me is not reviewed, approved or endorsed by Brocade and is provided solely as a convenience for Brocade customers. All systems and all networks are different and unique. If you have a service affecting network problem, please open a TAC service request for service through Brocade, or through your OEM equipment provider. If this provided you with a solution to this issue, please mark it with the button at the bottom "Accept as solution"
Occasional Contributor
Posts: 6
Registered: ‎11-28-2016

Re: SFP RX power is low

Hello expert,

Would you please help me in getting this understand too? this port is connected to san server, and has strange behavior.

SW6510:FID128:admin> portstatsshow 0
stat_wtx             1509602918  4-byte words transmitted
stat_wrx             4258714392  4-byte words received
stat_ftx             4184696882  Frames transmitted
stat_frx             3913439957  Frames received
stat_c2_frx          0           Class 2 frames received
stat_c3_frx          3913439957  Class 3 frames received
stat_lc_rx           0           Link control frames received
stat_mc_rx           0           Multicast frames received
stat_mc_to           0           Multicast timeouts
stat_mc_tx           0           Multicast frames transmitted
tim_rdy_pri          0           Time R_RDY high priority
tim_txcrd_z          34896661    Time TX Credit Zero (2.5Us ticks)
tim_txcrd_z_vc  0- 3:  0           0           34896661    0        
tim_txcrd_z_vc  4- 7:  0           0           0           0        
tim_txcrd_z_vc  8-11:  0           0           0           0        
tim_txcrd_z_vc 12-15:  0           0           0           0        
tim_latency_vc  0- 3:  1           1           1           1        
tim_latency_vc  4- 7:  1           1           1           1        
tim_latency_vc  8-11:  1           1           1           1        
tim_latency_vc 12-15:  1           1           1           1        
fec_cor_detected     0           Count of blocks that were corrected by FEC
fec_uncor_detected   0           Count of blocks that were left uncorrected by FEC
er_enc_in            0           Encoding errors inside of frames
er_crc               0           Frames with CRC errors
er_trunc             0           Frames shorter than minimum
er_toolong           0           Frames longer than maximum
er_bad_eof           0           Frames with bad end-of-frame
er_enc_out           141946      Encoding error outside of frames
er_bad_os            139463      Invalid ordered set
er_pcs_blk           0           PCS block errors
er_rx_c3_timeout     0           Class 3 receive frames discarded due to timeout
er_tx_c3_timeout     0           Class 3 transmit frames discarded due to timeout
er_unroutable        24          Frames that are unroutable
er_unreachable       31          Frames with unreachable destination
er_other_discard     24          Other discards
er_type1_miss        0           frames with FTB type 1 miss
er_type2_miss        0           frames with FTB type 2 miss
er_type6_miss        0           frames with FTB type 6 miss
er_zone_miss         0           frames with hard zoning miss
er_lun_zone_miss     0           frames with LUN zoning miss
er_crc_good_eof      0           Crc error with good eof
er_inv_arb           0           Invalid ARB
er_single_credit_loss 0           Single vcrdy/frame loss on link
er_multi_credit_loss 0           Multiple vcrdy/frame loss on link
phy_stats_clear_ts   0           Timestamp of phy_port stats clear
lgc_stats_clear_ts   0           Timestamp of lgc_port stats clear

Brocade Moderator
Posts: 251
Registered: ‎08-31-2009

Re: SFP RX power is low

Hello,

 

Please can you share the sfpshow output also?

If sfp rx power is very low, the issue is pobably on the other end on SFP side you have to replace first. Could be also due to a cable issue between the 2 ports. CRC errors associated to encoding errors were showing in the first portstatsshow output which means a physical layer issue on the data path.

Any and all information provided by me is not reviewed, approved or endorsed by Brocade and is provided solely as a convenience for Brocade customers. All systems and all networks are different and unique. If you have a service affecting network problem, please open a TAC service request for service through Brocade, or through your OEM equipment provider. If this provided you with a solution to this issue, please mark it with the button at the bottom "Accept as solution"
Occasional Contributor
Posts: 12
Registered: ‎04-08-2016

Re: SFP RX power is low

Hi Thierry,

 

Thank you for reply. Yes am working with server team here, to find the fault in server's SFP. However i wonder how this WWPN is able to login to one node of the SVC though its RX is very low here it is -15.4.

 

If it is able to login to one of node of the SVC  why not to another node  ( its 2node SVC ) ? Though its zoned with both the nodes.

 

Please share your thoughts..

Brocade Moderator
Posts: 251
Registered: ‎08-31-2009

Re: SFP RX power is low

[ Edited ]

Due to the physical layer issue and very low power received on the switch, all operations and logins on that port are by nature unpredictable. Suspicion is the login on one node has been completed and has failed due to frames lost to the other node. 

Any and all information provided by me is not reviewed, approved or endorsed by Brocade and is provided solely as a convenience for Brocade customers. All systems and all networks are different and unique. If you have a service affecting network problem, please open a TAC service request for service through Brocade, or through your OEM equipment provider. If this provided you with a solution to this issue, please mark it with the button at the bottom "Accept as solution"
Occasional Contributor
Posts: 12
Registered: ‎04-08-2016

Re: SFP RX power is low

Thank you so much.

Brocade Moderator
Posts: 251
Registered: ‎08-31-2009

Re: SFP RX power is low

You are welcome!

Please mark the post as accept as a solution if this match with your expectation.

 

 

Any and all information provided by me is not reviewed, approved or endorsed by Brocade and is provided solely as a convenience for Brocade customers. All systems and all networks are different and unique. If you have a service affecting network problem, please open a TAC service request for service through Brocade, or through your OEM equipment provider. If this provided you with a solution to this issue, please mark it with the button at the bottom "Accept as solution"

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