LinuxQuestions.org
Visit Jeremy's Blog.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking
User Name
Password
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

Notices


Reply
  Search this Thread
Old 10-29-2014, 05:33 PM   #1
psycroptic
Member
 
Registered: Aug 2011
Location: USA
Distribution: ArchLinux - 3.0 kernel
Posts: 349

Rep: Reputation: Disabled
Duplicate & Reordered packets?


The "netalyzr" network information site, located below:

http://netalyzr.icsi.berkeley.edu/

reports under the "Network Link Access Properties" unit that it observed 2 duplicate & 1 redordered packet on the upload bandwidth test, and 49 duplicate & 60 reordered packets on the downoad test. During a few long-term pings i've left running from my site to various others on the internet, it is rare but i have seen a "DUP!" message there as well.

Would this be cause for concern? And if so, what would be the possible cause/solution? My router is a PC running ArchLinux, with an Intel I350 T4 quad-port PCIe NIC handling the WAN/LAN interfaces.
 
Old 10-30-2014, 04:32 PM   #2
unSpawn
Moderator
 
Registered: May 2001
Posts: 29,415
Blog Entries: 55

Rep: Reputation: 3600Reputation: 3600Reputation: 3600Reputation: 3600Reputation: 3600Reputation: 3600Reputation: 3600Reputation: 3600Reputation: 3600Reputation: 3600Reputation: 3600
Quote:
Originally Posted by psycroptic View Post
Would this be cause for concern?
Depends on how often you experience it and if you're the receiver asking for or the sender of copies. What does this return:
Code:
ifconfig -a; netstat -s

Quote:
Originally Posted by psycroptic View Post
And if so, what would be the possible cause/solution?
The kernels network stack will automagically attempt to compensate using a host of measures that are part of TCP/IP like congestion control but as to the solution this may or may not be yours to implement where adverse network conditions are beyond your realm of influence as you can't control or compensate for problems caused by the likes of traffic shaping, route problems, hardware glitches in routers or firewalls, etc, etc. For more see for example http://www.tcpipguide.com/index.htm.
 
Old 11-01-2014, 10:39 PM   #3
psycroptic
Member
 
Registered: Aug 2011
Location: USA
Distribution: ArchLinux - 3.0 kernel
Posts: 349

Original Poster
Rep: Reputation: Disabled
"ifconfig -a"
Code:
external: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 68.52.---:---  netmask 255.255.254.0  broadcast 255.255.255.255
        inet6 fe80::a236:9fff:fe14:1ec  prefixlen 64  scopeid 0x20<link>
        ether a0:36:9f:14:01:ec  txqueuelen 1000  (Ethernet)
        RX packets 91887771  bytes 36681894926 (34.1 GiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 110899791  bytes 138721443589 (129.1 GiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device memory 0xdfa00000-dfafffff

internal: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.16.16.1  netmask 255.255.0.0  broadcast 172.16.255.255
        inet6 -:-:-:-:-:-:-:-  prefixlen 64  scopeid 0x0<global>
        inet6 fe80::a236:9fff:fe14:1ed  prefixlen 64  scopeid 0x20<link>
        ether a0:36:9f:14:01:ed  txqueuelen 1000  (Ethernet)
        RX packets 110623596  bytes 138147693542 (128.6 GiB)
        RX errors 0  dropped 783  overruns 0  frame 0
        TX packets 89044695  bytes 35981848024 (33.5 GiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device memory 0xdfb00000-dfbfffff

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 0  (Local Loopback)
        RX packets 52  bytes 5428 (5.3 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 52  bytes 5428 (5.3 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

tun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1500
        inet 10.11.12.1  netmask 255.255.255.255  destination 10.11.12.2
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 100  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

vpn: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.172.172.1  netmask 255.255.255.252  broadcast 10.172.172.3
        inet6 fe80::a236:9fff:fe14:1ee  prefixlen 64  scopeid 0x20<link>
        ether a0:36:9f:14:01:ee  txqueuelen 1000  (Ethernet)
        RX packets 310633  bytes 433245469 (413.1 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 156085  bytes 9332152 (8.8 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device memory 0xdfc00000-dfcfffff
"netstat -s"
Code:
Ip:
    185399320 total packets received
    3 with invalid headers
    179467111 forwarded
    0 incoming packets discarded
    5859842 incoming packets delivered
    181628186 requests sent out
    2 dropped because of missing route
    372 fragments dropped after timeout
    19836 reassemblies required
    9708 packets reassembled ok
    372 packet reassembles failed
    54 fragments received ok
    139 fragments created
Icmp:
    2991 ICMP messages received
    2406 input ICMP message failed.
    InCsumErrors: 135
    ICMP input histogram:
        destination unreachable: 2332
        timeout in transit: 19
        echo requests: 489
        echo replies: 16
    77430 ICMP messages sent
    0 ICMP messages failed
    ICMP output histogram:
        destination unreachable: 76601
        time exceeded: 275
        echo request: 65
        echo replies: 489
IcmpMsg:
        InType0: 16
        InType3: 2332
        InType8: 489
        InType11: 19
        OutType0: 489
        OutType3: 76601
        OutType8: 65
        OutType11: 275
Tcp:
    22 active connections openings
    18 passive connection openings
    0 failed connection attempts
    8 connection resets received
    1 connections established
    146512 segments received
    217040 segments send out
    138 segments retransmited
    0 bad segments received.
    2219 resets sent
Udp:
    184186 packets received
    3405 packets to unknown port received.
    0 packet receive errors
    1582 packets sent
    0 receive buffer errors
    0 send buffer errors
UdpLite:
TcpExt:
    1 invalid SYN cookies received
    8 ICMP packets dropped because they were out-of-window
    12 TCP sockets finished time wait in fast timer
    270 delayed acks sent
    Quick ack mode was activated 5 times
    49752 packets directly queued to recvmsg prequeue.
    237006 bytes directly in process context from backlog
    85898170 bytes directly received in process context from prequeue
    9900 packet headers predicted
    61918 packets header predicted and directly queued to user
    57292 acknowledgments not containing data payload received
    5707 predicted acknowledgments
    9 times recovered from packet loss by selective acknowledgements
    Detected reordering 1 times using FACK
    1 congestion windows recovered without slow start by DSACK
    1 timeouts in loss state
    13 fast retransmits
    3 forward retransmits
    3 retransmits in slow start
    3 other TCP timeouts
    TCPLossProbes: 107
    TCPLossProbeRecovery: 100
    5 DSACKs sent for old packets
    110 DSACKs received
    2 connections reset due to unexpected data
    3 connections aborted due to timeout
    TCPDSACKIgnoredNoUndo: 100
    TCPSackShiftFallback: 75
    IPReversePathFilter: 10
    TCPRcvCoalesce: 340
    TCPOFOQueue: 3553
    TCPAutoCorking: 73835
    TCPSynRetrans: 1
    TCPOrigDataSent: 171943
IpExt:
    InTruncatedPkts: 1
    InBcastPkts: 14310
    InOctets: 174614653790
    OutOctets: 338940895012
    InBcastOctets: 4259341
    InNoECTPkts: 203426130
    InECT1Pkts: 111861
    InECT0Pkts: 190854
    InCEPkts: 41036
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
[SOLVED] NS2: How receive CBR packets at my own agent and duplicate them for new destination?? fahimeh_ak Programming 5 09-06-2016 11:12 PM
Drives reordered, now it won't boot? JamesGT Slackware 1 03-28-2014 10:21 PM
VDE Swtich- Packets Duplicate? dman777 Linux - Networking 0 09-27-2011 08:43 PM
SAN devices get reordered every now and then epolanco Linux - Enterprise 1 07-22-2009 10:58 AM
SAN devices get reordered every now and then epolanco Linux - Hardware 1 07-22-2009 10:45 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Networking

All times are GMT -5. The time now is 03:23 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration