Extended ACLs are advanced than the Standard ACLs. Unlike the Standard Access Lists where it checks only the Source IP Address to control the flow of the packets, Extended ACLs can check the
Source & Destination Address
Protocols (IP,ICMP,TCP,UDP)
Source & Destination ports
Gratuitous ARP is a feature of the Address Resolution Protocol wherein the host broadcasts an ARP request for its own hardware address.
IP packet forwarding is the process of routing packets between network interfaces on one system. A packet arriving on one network interface and addressed to a host on a different network is forwarded to the appropriate interface. While this is a job for the network router, Servers with multiple interfaces connected to different network can perform this action as well. This behaviour as a router is a default in Sun Solaris Operating Systems.
netstat is one of the most commonly used tool in Windows and UNIX & Linux operating systems to troubleshoot TCP/IP connections. Netstat displays active TCP connections, ports on which the computer is listening, Ethernet statistics, the IP routing table, IPv4 statistics (for the IP, ICMP, TCP, and UDP protocols), and IPv6 statistics (for the IPv6, ICMPv6, TCP over IPv6, and UDP over IPv6 protocols). Used without parameters, netstat displays active TCP connections. (more…)