Join Log in
Score:1
skb007 avatar Server

iperf3 showing packetloss between 2 directly connected servers

in flag
skb007

I have 2 Dell PowerEdge-R620 servers with following configuration Processor: 2 X Intel(R) Xeon(R) CPU E5-2637 v2 @ 3.50GHz RAM: 64GB Storage: 10 SAS drives (10K RPM) with RAID 10. NIC: QUAD Ports 2 X 10GB (INTEL X540-AT2)and 2 X 1GB (INTEL I-350) OS: RHEL 8.3

Both servers are directly connected to each other using cat7 cable via 10G interface. We want to test the network performance for UDP packets matching the size of a VOIP/RTP packet.

server2 is running as iperf3 server server2# iperf3 -s

I get 20%-25% packet loss on receiving side when I run the following on server1 command server1# iperf3 -u --length 238 -t 30 -c server1 -b 0

I don't get any packet loss if I limit bitrate to 200Mbps (b 200M). I start to see the packet loss as soon as bitrate goes beyond 200Mbps.

NIC driver and firmware are latest. Cable has tested good. #tuned-adm list shows that the current active profile: throughput-performance.

ethtool -g eno1 shows that ring RX/TX set to 512. Changing RX/TX to 1024 or 2048 did not make any difference.

iperf3 being a single thread application, I though may be cpu core is getting chocked up and dropping packets. But I see packet loss happening if I run 2 parallel tests with bitrate 200Mbps each.

I see "packet receive errors" and "receive buffer errors" increasing while I run the test.

# netstat -su
IcmpMsg:
    InType0: 5962
    InType3: 2188543
    InType5: 25970
    InType8: 169
    OutType0: 169
    OutType3: 2201341
    OutType8: 6451
Udp:
    798970636 packets received
    488445853 packets to unknown port received
    **50427006 packet receive errors**
    2017757523 packets sent
    **50427006 receive buffer errors**
    0 send buffer errors
    IgnoredMulti: 20927
UdpLite:
IpExt:
    InMcastPkts: 68164
    OutMcastPkts: 621
    InBcastPkts: 20927
    InOctets: 338232375898
    OutOctets: 418403184273
    InMcastOctets: 2628618
    OutMcastOctets: 29705
    InBcastOctets: 3387318
    InNoECTPkts: 1350444521
    InECT0Pkts: 9
MPTcpExt:

Any thoughts?

77
0 + 0
ธงชาติไทย
Elon Musk
I sit in a Tesla and translated this thread with Ai:

mangohost

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.