Home / Performance issues / Performance issues -Network

Performance issues -Network

Network Statistics
netstat displays the contents of various network-related data structures in depending on the options selected.This command is very useful during the network troubleshooting. In Solaris we can monitor the packets using snoop command.There are other third party tools like sniffer can used for deep level troubleshooting.


Syntax:
netstat <option/s>
multiple options can be given at one time.
Options
-a – displays the state of all sockets.
-r – shows the system routing tables
-i – gives statistics on a per-interface basis.
-m – displays information from the network memory buffers. On Solaris, this shows statistics

for STREAMS
-p [proto] – retrieves statistics for the specified protocol
-s – shows per-protocol statistics. (some implementations allow -ss to remove fileds with a value of 0 (zero) from the display.)
-D – display the status of DHCP configured interfaces.
-n do not lookup hostnames, display only IP addresses.
-d (with -i) displays dropped packets per interface.
-I [interface] retrieve information about only the specified interface.
-v be verbose
interval – number for continuous display of Statistics.

  • To monitor the packet statics with interval of 5 seconds, use the below command.
  • bash-3.00# netstat -i interval 5
    input e1000g output input (Total) output
    packets errs packets errs colls packets errs packets errs colls
    98530 0 18658 0 0 131776 0 51904 0 0
    1 0 1 0 0 1 0 1 0 0
    1 0 1 0 0 1 0 1 0 0
    1 0 1 0 0 1 0 1 0 0
    1 0 1 0 0 1 0 1 0 0
  • Using the below command,we can monitor the network Statistics for particular interface with specified interval.
  • bash-3.00# netstat -i -I e1000g0 interval 5
    input e1000g output input (Total) output
    packets errs packets errs colls packets errs packets errs colls
    98561 0 18684 0 0 131807 0 51930 0 0
    1 0 1 0 0 1 0 1 0 0
    1 0 1 0 0 1 0 1 0 0
    2 0 2 0 0 2 0 2 0 0
    1 0 1 0 0 1 0 1 0 0
  • To see the summary of the network  statics    
  • bash-3.00# netstat -i
    Name Mtu Net/Dest Address Ipkts Ierrs Opkts Oerrs Collis Queue
    lo0 8232 loopback localhost 33216 0 33216 0 0 0
    e1000g0 1500 sfos sfos 98417 0 18582 0 0 0

This option is used to diagnose the network problems when the connectivity is there but it is slow in response .Values to look at:
Collisions (Collis)
Output packets (Opkts)
Input errors (Ierrs)
Input packets (Ipkts)

If the Colis and Input errors are more, definitively system has some network issue.Need to check with network team for “collis”.Ierrs: most of the time happened in layer 4 .Need to check with Operating system vendor.If your system is overloaded in network,better to add one more interface in the aggregation .

To troubleshoot in packet level,snoop is very useful tool which is available in  in Solaris.Using this tool you can determined end to end transfer packed and packet drop.


Thank you for reading this article.Please leave a comment if you have any doubt ,i will get back to you as soon as possible.

VMTURBO-CLOUD-CAPACITY

Leave a Reply

Your email address will not be published. Required fields are marked *