1. What is the effect of the first "ifconfig ethxx down" command on the system's ARP cache ?
Answer:
The arp table becomes empty after the first "ifconfig eth1 down"
[root@localhost ~]# arp -n Address HWtype HWaddress Flags Mask Iface 142.204.141.131 ether 00:0E:7F:3C:A8:F3 C eth1 142.204.141.129 ether 00:0E:0C:4B:31:5C C eth1 [root@localhost ~]# ifconfig eth1 down [root@localhost ~]# arp -n [root@localhost ~]# ifconfig eth1 up [root@localhost ~]# arp -n
2. What command disable ARP on a network interface?
Answer:
To disable ARP on a network interface named 'ethxxx', one would use a command of the form 'ifconfing ethxxx -arp'.
3. How do you enable ARP on a network interface if it has been disabled?
Answer:
To re-enable ARP on a network interface named 'ethxxx', one would use a command of the form 'ifconfig ethxxx arp'.
4. What is the consequence of disabling ARP on a network interface?
Answer:
If ARP has been disabled on a network interface, ARP packets recieved by that interface will be dropped. This prevents the machine from either resolving the corresponding MAC address for a particular IP address or from responding to a requestion for such resolution.