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-   -   can't delete arp entries (https://www.linuxquestions.org/questions/linux-networking-3/cant-delete-arp-entries-887928/)

YaMaHaBoB 06-23-2011 08:03 AM

can't delete arp entries
 
So I have some entries like the ones below. I have a system setup to do all the routing/dhcp/dns. This is a private network for education purposes only, and I have no idea how half of these addresses got in the arp table.

shell>arp -n
192.58.128.30 (incomplete) eth0
192.228.79.201 (incomplete) eth0
192.36.148.17 (incomplete) eth0
192.168.1.100 ether 00:11:22:33:44:55 C eth0
192.8.10.90 (incomplete) eth0
10.0.0.100 ether 00:11:22:33:44:55 C eth0
10.0.0.1 * <from_interface> MP eth0

I have a private network with 10.x.x.x, mask 255.0.0.0, and one addition computer with a static 192.168.1.100. There are only three computers (hooked up through a switch).

I've tried deleting entries manually i.e.:
arp -d 192.58.128.30

and get the error:
SIOCDARP(dontpub): Network is unreachable

I can't figure out how to just clear the table. That's all I want. Is that too much to ask? I also noticed in Wireshark that packets are constantly being sent to find the MAC address that these IPs belong too. I really want that to stop happening.

EDIT:
I have also tried using ip neighbor. I ran "ip neighbor del 192.58.128.30 dev eth0", and it gave no errors but didn't remove the entry. All the ones without a MAC are also listed as FAILED in ip neighbor.

Ideas?
Thanks in advance

YaMaHaBoB 06-23-2011 08:16 AM

I absolutely can't believe this. Two days looking at this problem, I finally make a post and found a solution. I accidentally stumbled up where you can turn ARP off! For anyone with the same issue, I used ip link to fix the issue by first turning ARP off and turning ARP back on.

Code:

ip link set arp off dev eth0
ip link set arp on dev eth0


usman317 12-28-2022 01:17 AM

If you turn off the arp link, how would your device be able to get the mac address of any other device added to the network.

jefro 12-28-2022 09:29 AM

Generally arp command is 10-10- or 10:10: form. Not sure I've seen a 10.10. but maybe.

Use arp option to show static and dynamic entries.

xlfs-0.2 02-01-2023 04:11 PM

you don't want to delete arp entries. it messes things up no matter what you think the situation is.

let the kernel do it. it will do it correctly.


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