Corrected FEC errors are pretty normal for 400G FR4 On Wednesday, April 17th, 2024 at 3:36 PM, Aaron Gould <aar...@gvtc.com> wrote:
> We recently added MPC10E-15C-MRATE cards to our MX960's to upgrade our core > to 400g. During initial testing of the 400g interface (400GBASE-FR4), I see > constant FEC errors. FEC is new to me. Anyone know why this is occurring? > Shown below, is an interface with no traffic, but seeing constant FEC errors. > This is (2) MX960's cabled directly, no dwdm or anything between them... > just a fiber patch cable. > > {master} > me@mx960> clear interfaces statistics et-7/1/4 > > {master} > me@mx960> show interfaces et-7/1/4 | grep rror | refresh 2 > ---(refreshed at 2024-04-17 14:18:53 CDT)--- > Link-level type: Ethernet, MTU: 1514, MRU: 1522, Speed: 400Gbps, BPDU > Error: None, Loop Detect PDU Error: None, Loopback: Disabled, Source > filtering: Disabled, > Bit errors 0 > Errored blocks 0 > Ethernet FEC statistics Errors > FEC Corrected Errors 0 > FEC Uncorrected Errors 0 > FEC Corrected Errors Rate 0 > FEC Uncorrected Errors Rate 0 > ---(refreshed at 2024-04-17 14:18:55 CDT)--- > Link-level type: Ethernet, MTU: 1514, MRU: 1522, Speed: 400Gbps, BPDU > Error: None, Loop Detect PDU Error: None, Loopback: Disabled, Source > filtering: Disabled, > Bit errors 0 > Errored blocks 0 > Ethernet FEC statistics Errors > FEC Corrected Errors 4302 > FEC Uncorrected Errors 0 > FEC Corrected Errors Rate 8 > FEC Uncorrected Errors Rate 0 > ---(refreshed at 2024-04-17 14:18:57 CDT)--- > Link-level type: Ethernet, MTU: 1514, MRU: 1522, Speed: 400Gbps, BPDU > Error: None, Loop Detect PDU Error: None, Loopback: Disabled, Source > filtering: Disabled, > Bit errors 0 > Errored blocks 0 > Ethernet FEC statistics Errors > FEC Corrected Errors 8796 > FEC Uncorrected Errors 0 > FEC Corrected Errors Rate 146 > FEC Uncorrected Errors Rate 0 > ---(refreshed at 2024-04-17 14:18:59 CDT)--- > Link-level type: Ethernet, MTU: 1514, MRU: 1522, Speed: 400Gbps, BPDU > Error: None, Loop Detect PDU Error: None, Loopback: Disabled, Source > filtering: Disabled, > Bit errors 0 > Errored blocks 0 > Ethernet FEC statistics Errors > FEC Corrected Errors 15582 > FEC Uncorrected Errors 0 > FEC Corrected Errors Rate 111 > FEC Uncorrected Errors Rate 0 > ---(refreshed at 2024-04-17 14:19:01 CDT)--- > Link-level type: Ethernet, MTU: 1514, MRU: 1522, Speed: 400Gbps, BPDU > Error: None, Loop Detect PDU Error: None, Loopback: Disabled, Source > filtering: Disabled, > Bit errors 0 > Errored blocks 0 > Ethernet FEC statistics Errors > FEC Corrected Errors 20342 > FEC Uncorrected Errors 0 > FEC Corrected Errors Rate 256 > FEC Uncorrected Errors Rate 0 > > {master} > me@mx960> show interfaces et-7/1/4 | grep "put rate" > Input rate : 0 bps (0 pps) > Output rate : 0 bps (0 pps) > > {master} > me@mx960> show interfaces et-7/1/4 > Physical interface: et-7/1/4, Enabled, Physical link is Up > Interface index: 226, SNMP ifIndex: 800 > Link-level type: Ethernet, MTU: 1514, MRU: 1522, Speed: 400Gbps, BPDU > Error: None, Loop Detect PDU Error: None, Loopback: Disabled, Source > filtering: Disabled, > Flow control: Enabled > Pad to minimum frame size: Disabled > Device flags : Present Running > Interface flags: SNMP-Traps Internal: 0x4000 > Link flags : None > CoS queues : 8 supported, 8 maximum usable queues > Schedulers : 0 > Last flapped : 2024-04-17 13:55:28 CDT (00:36:19 ago) > Input rate : 0 bps (0 pps) > Output rate : 0 bps (0 pps) > Active alarms : None > Active defects : None > PCS statistics Seconds > Bit errors 0 > Errored blocks 0 > Ethernet FEC Mode : FEC119 > Ethernet FEC statistics Errors > FEC Corrected Errors 801787 > FEC Uncorrected Errors 0 > FEC Corrected Errors Rate 2054 > FEC Uncorrected Errors Rate 0 > Link Degrade : > Link Monitoring : Disable > Interface transmit statistics: Disabled > > Logical interface et-7/1/4.0 (Index 420) (SNMP ifIndex 815) > Flags: Up SNMP-Traps 0x4004000 Encapsulation: ENET2 > Input packets : 1 > Output packets: 1 > Protocol inet, MTU: 1500 > Max nh cache: 75000, New hold nh limit: 75000, Curr nh cnt: 1, Curr new > hold cnt: 0, NH drop cnt: 0 > Flags: Sendbcast-pkt-to-re > Addresses, Flags: Is-Preferred Is-Primary > Destination: 10.10.10.76/30, Local: 10.10.10.77, Broadcast: > 10.10.10.79 > > -- > -Aaron