arping – a utility that sends arp packets to a specified host and displays responses.
Continue reading “Using the arping utility”
It is executed from the root user, in Linux, for this, from under a regular user, you can append before each sudo command.
Let’s look at the status of Proxy ARP (1 – enabled, 0 – disabled):
You can look at a specific network interface (where eth0 is the name of the network interface):
You can enable Proxy ARP as follows:
echo 1 > /proc/sys/net/ipv4/conf/all/proxy_arp
echo 1 > /proc/sys/net/ipv4/conf/eth0/proxy_arp
sudo sysctl net.ipv4.conf.all.proxy_arp=1
sudo sysctl net.ipv4.conf.eth0.proxy_arp=1
sudo sysctl -p
To turn off the Proxy ARP commands are similar, you only need to specify 0 instead of 1.
The above changes will be reset after restarting the system so that this does not happen, open the file /etc/sysctl.conf in any text editor:
sudo nano /etc/sysctl.conf
If necessary, you can see the incoming ARP packets via tcpdump:
sudo tcpdump -n -i eth0 -e arp
Here is an example of searching ARP records for mac address:
Continue reading “How to view ARP and MAC addresses on Cisco”