Apr 242008
 


Not so often we would end up troubleshooting or manipulating ARP and ARP tables in Sun Solaris. However, following are some of the useful commands which can help when required. The following commands will help you display,modify,add,delete ARP entries in Sun Solaris ARP table.

Display ARP table

sunsolaris# arp -a
Net to Media Table: IPv4
Device   IP Address               Mask      Flags   Phys Addr
—— ——————– ————— —– —————
pcn0   192.168.0.1          255.255.255.255       00:18:4d:f8:a4:6e
pcn0   192.168.0.2          255.255.255.255       00:13:ce:85:0e:e1
pcn0   sunsolaris            255.255.255.255 SP    00:0c:29:d3:76:89
pcn0   BASE-ADDRESS.MCAST.NET 240.0.0.0       SM    01:00:5e:00:00:00

Delete an ARP entry

sunsolaris# arp -d 192.168.0.1
192.168.0.1 (192.168.0.1) deleted

To verify the entry indeed is deleted

sunsolaris# arp -a
Net to Media Table: IPv4
Device   IP Address               Mask      Flags   Phys Addr
—— ——————– ————— —– —————
pcn0   192.168.0.2          255.255.255.255       00:13:ce:85:0e:e1
pcn0   solaris10            255.255.255.255 SP    00:0c:29:d3:76:89
pcn0   BASE-ADDRESS.MCAST.NET 240.0.0.0       SM    01:00:5e:00:00:00

You can see the ARP entry for 192.168.0.1 is longer found.

Add a Static entry

sunsolaris# arp -s 192.168.0.1 00:18:4d:f8:a4:6e

Syntax is

arp -s HOSTNAME MAC-Address <pub/temp/trail>

where

pub – publishes the ARP entries to other hosts on the network

temp – Temporary entry

trail – Allows Trailer Encapsulations to be sent to host

You can also read static entries from a file. This can come handy if you decide that all ARP entries are static and no ARP requests are sent and received from the system. You can add the static entries onto a file and add the arp command onto the network init scripts in /etc/rc2.d/

To read from file

sunsolaris# arp -f /etc/host_mac

where /etc/host_mac is my file name from where the ARP entries are read.

To check the current ARP caching time

sunsolaris# ndd -get /dev/arp arp_cleanup_interval
500000

where 500000 in milliseconds indicates 5mins

To modify ARP Cache timing, click here

  7 Responses to “Display/Add/Delete/modify ARP entries in ARP Table”

  1. very good useful details.
    Thank you so much

  2. useful info.
    Thank you

  3. “where 500000 in milliseconds indicates 5mins”

    That is wrong. 500.000 ms = 500 seconds diferent from 5 minutes
    ;)

    The info in this post is usefull.
    thanks

  4. Is there any way to clear the entire ARP table?

  5. which command is used to clear the ARP table?

  6. Hi,
    I have accidentally deleted a ARP entry in my sun solaris machine. The session got terminated immediately thereafter. And I could no longer login to the machine.

    The comand I used was arp -d SERVER01 , where SERVER01 was the hostname of the machine i was logged in and executing the command.

    I can no longer login into the system. Could you please suggest me a way to solve this ?

    Thanks and Regards, A

  7. thanks so much, very clear

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