Posted on November 26, 2018 6:57 pm
 |  Asked by Emmanuel Arrazola Flores
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I have configured a pair of ports on an Arista DCS-7280SR2A-48YC6-R / 4.19.10M, that will be used by an Cisco UCS240, but the ports appears not to be connected.

Arista_dummy#sh int status
Port Name Status Vlan Duplex Speed Type Flags
Et3 notconnect 100 a-full a-1G 1000BASE-T
Et4 notconnect 101 a-full a-1G 1000BASE-T
Et5 notconnect 100 a-full a-1G 1000BASE-T
Et6 notconnect 101 a-full a-1G 1000BASE-T

We are using a 1000BASE-T transceiver. When we validate the negotiation detail, it`s appears that we don`t receive the singnal from the DTE/DCE, even when they are physically connected.

Arista_dummy#sh int eth1 negotiation detail
Ethernet1 :

Auto-Negotiation Mode 10/100/1000 BASE-T (IEEE Clause 28)
Auto-Negotiation Status Negotiating

Advertisements Speed Duplex Pause
————— ———- ——————–
Local 1G full None
Link Partner None None None

Resolution Auto-speed auto None

Arista_dummy#sh int eth1 phy detail
Current System Time: Thu Nov 22 06:58:35 2018
Current State Changes Last Change
PHY state linkDown 2 10 days, 8:21:56 ago
Interface state down 3 4:32:42 ago
HW resets 0 never
Transceiver 1000BASE-T 4 4:32:42 ago
Transceiver SN AHN1839000ER
Oper speed 25Gbps
Interrupt Count 0
Diags mode normalOperation
Model BCM88675/BCM88375 (0x18c086,0x37,0x0)
Loopback none
Xcvr EEPROM read timeout 0 never
Spurious xcvr detection 0 never
DOM control/status fail 0
Presence indication xcvrPresent 5 4:32:42 ago
Bad EEPROM checksums 0 never
RX_LOS since system boot False 3 4:39:01 ago
RX_LOS since insertion 0
TX_FAULT since system boot False 4 4:32:42 ago
TX_FAULT since insertion 1
PMA/PMD RX signal detect ok 3 4:32:36 ago
Forward Error Correction None
PCS RX link status down 0 never
PCS high BER ok 0 never
PCS err blocks 0 never
PCS block lock no block lock 0 never
PCS BER 0 0 never
LN RXPPM CLK90 CLKP1 PF(M,L) VGA DCO DFE(1, 2, 3, 4, 5, 6) TXPPM TXEQ(n1, m ,p1,p2,p3) BIP
0 36 32 0 10,0 13 63 35, 0, 0, 0, 0, 0 0 12,100, 0, 0, 0 0

– UTP were validted and they are fine
– Transcivers are fine
– End ports are enable

Do you know why this is happened?

Posted by Alexis Dacquay
Answered on November 28, 2018 6:46 am

How are your earlier ports Eth1 and Eth2?
Check whether the 4 ports Eth 1-4 have got the same speed, and also 5-8 got the same speed.
Do you have anything Err-disable?

interface Ethernet1
speed forced
interface Ethernet2
speed forced

interface Ethernet3
speed forced

interface Ethernet4
speed forced




25G SFP Port Grouping
The 10G/25G capable SFP ports on the 7280R are arranged as a group of 4
ports sharing common speed configurations. The set of 4 ports in each group
have a single port speed setting – 1/10G or 25G. The first configured port
determines the speed of all other ports in the group. This also applies to 100G QSFP ports
in break out mode for 1/10G or 25G speeds.

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