Date created: Thursday, April 10, 2025 2:23:08 PM. Last modified: Friday, April 11, 2025 11:42:32 AM
Service Activation Test (SAT) Link Qualification
Compatibility
Even though the Arista docs states that 7280SR3-48Y variants are not supported, this was tested on:
lab#show ver | inc SR3K
Arista DCS-7280SR3K-48YC8A-F
lab#show hardware system forwarding-chips
Slot Chip Label Chip Version Chip Name Forwarding Agent
------ ------------ ------------ --------- ----------------
Switch SwitchAsic-0 88820A1 Jericho2c Sand
lab#show platform fap Switches currently in the system Name Type Device Revision ---------- -------------- --------------- -------------- Fap0 Jericho2 Jericho2c A1
BCM88800 is the Jericho2C chip, but BCM88820 is the Qumran2C chip. The CLI output is not quite right here. Perhaps in EOS Jericho is reported because the overall Broadcom family is Jericho ("Sand" in EOS terminology), because the only difference between these two chips is that Q has no fabric ports.
After speaking with Arista, devices with the Q2C-T2 ASIC aren't supported (which is used in 7280SR3-* and 7280SR3M-*, it seems 7280SR3K-* has different Q2C chip which is why it worked).
Testing
A cable is looping two 10Gbps interfaces on the same router together (Et11 and Et12). Eth11 is Tx, Eth12 is Rx. Here almost 10Gbps is sent and reflected back. The test is set to 9.8Gbps. This is not the layer 1 traffic rate, which means that setting this test to 10Gbps will result in a layer 1 speed greater than the port speed, and the test will measure packet loss and mark the test as a failure:
lab#conf t
lab(config)#monitor link qualification generators
lab(config-mon-lq-gen)#show active
monitor link qualification generators
profile jt
traffic rate 9800 mbps
packet size 1500 bytes
traffic duration 100 seconds
interface Ethernet11 profile jt
no disabled
lab(config-mon-lq-gen)#exit
lab(config)#monitor ethernet reflectors
lab(config-reflectors)#show active
monitor ethernet reflectors
reflector interface Ethernet12
direction in
lab(config-reflectors)#end
lab#show monitor link qualification generators
Interface: Ethernet11
State: not started
lab#show monitor link qualification generators profiles
Link Qualification Profile: jt
Packet size: 1500 bytes
Link qualification duration: 100 seconds
Traffic rate: 9800 mbps
lab#show monitor ethernet reflectors
Ethernet reflector interface: Ethernet12
Direction: in
MAC action: not configured
Status: active
lab#clear counters ethernet 11
lab#clear counters ethernet 12
lab#start monitor link qualification generators interface ethernet 11
lab#show monitor link qualification generators
Interface: Ethernet11
State: complete (successful)
Start time: 0:02:11 ago
End time: 0:00:31 ago
Packet size: 1500
Link qualification duration: 100
Traffic rate: 9780517 kbps
Packets sent: 81504316
Packets received: 81504316
Packets dropped: 0
Packet transmit errors: 0
Packet receive errors: 0
Octets sent: 122256474000
Octets received: 122256474000
# After the test is completed, all packets sent and received with no errors or drops:
lab#show int ethernet 11
Ethernet11 is up, line protocol is up (connected)
Hardware is Ethernet, address is
generator
Ethernet MTU 10218 bytes, Ethernet MRU 10240 bytes, BW 10000000 kbit
Full-duplex, 10Gb/s, auto negotiation: off, uni-link: disabled
Up 101 days, 22 hours, 41 minutes, 49 seconds
Loopback Mode : None
0 link status changes since last clear
Last clearing of "show interface" counters 0:02:21 ago
5 seconds input rate 88.2 Mbps (0.9% with framing overhead), 7350 packets/sec
5 seconds output rate 88.2 Mbps (0.9% with framing overhead), 7350 packets/sec
81504316 packets input, 122256474000 bytes
Received 0 broadcasts, 0 multicast
0 runts, 0 giants
0 input errors, 0 CRC, 0 alignment, 0 symbol, 0 input discards
0 PAUSE input
81504316 packets output, 122256474000 bytes
Sent 0 broadcasts, 0 multicast
0 output errors, 0 collisions
0 late collision, 0 deferred, 0 output discards
0 PAUSE output
# After the test is completed, all packets sent and received with no errors or drops:
lab#show int ethernet 12
Ethernet12 is up, line protocol is up (connected)
Hardware is Ethernet, address is
ingress reflector
Ethernet MTU 10218 bytes, Ethernet MRU 10240 bytes, BW 10000000 kbit
Full-duplex, 10Gb/s, auto negotiation: off, uni-link: disabled
Up 101 days, 22 hours, 42 minutes, 13 seconds
Loopback Mode : None
0 link status changes since last clear
Last clearing of "show interface" counters 0:02:46 ago
5 seconds input rate 478 kbps (0.0% with framing overhead), 40 packets/sec
5 seconds output rate 478 kbps (0.0% with framing overhead), 40 packets/sec
81504316 packets input, 122256474000 bytes
Received 0 broadcasts, 0 multicast
0 runts, 0 giants
0 input errors, 0 CRC, 0 alignment, 0 symbol, 0 input discards
0 PAUSE input
81504316 packets output, 122256474000 bytes
Sent 0 broadcasts, 0 multicast
0 output errors, 0 collisions
0 late collision, 0 deferred, 0 output discards
0 PAUSE output
With the test rate set to 9.8Gbps we can see the interface just touches 100% utilisation when framing overhead is taken into account:
lab#show interfaces eth11 | inc Gbps 5 seconds input rate 9.87 Gbps (100.1% with framing overhead), 822734 packets/sec 5 seconds output rate 9.87 Gbps (100.0% with framing overhead), 822796 packets/sec lab#show interfaces eth11 counters rates Port Name Intvl In Mbps % In Kpps Out Mbps % Out Kpps Et11 0:05 9842.7 99.7% 820 9842.2 99.7% 820
This Q2C ASIC also has no problems generating 100Gbps of traffic:
lab#show interfaces et52/1 counters rates
Port Name Intvl In Mbps % In Kpps Out Mbps % Out Kpps
Et52/1 0:05 98523.1 99.8% 8210 98523.6 99.8% 8210
lab#show int eth52/1 | inc Gbps
5 seconds input rate 98.5 Gbps (99.8% with framing overhead), 8211274 packets/sec
5 seconds output rate 98.5 Gbps (99.8% with framing overhead), 8211316 packets/sec