ccna 200-301 network simulator tools plus wilmington

ccna 200-301 network simulator tools plus wilmington.Figure 244ARP JThe "arp" command can be used to check the ARP cache table.The "arp" command can be used to check the ARP cache table of the local machine, from which you can find the MAC address corresponding to a certain IP address. Readers can also use the "arp -d" command to delete the local ARP cache and the "arp -s" command to bind the IP address to the MAC address.For an explanation and demonstration of how ARP works and the message format, please watch the video file "Video \2-l.wrPoQ" on the CD.Note: If a host needs to access a remote host, the destination MAC address encapsulated in the data frame is not the MAC address of the remote host, but the MAC address of the gateway.This is explained later in this chapter.Proxy ARP (Proxy ARP) The ARP protocol introduced earlier can help a host or router to know the MAC address corresponding to an IP address on the local Ethernet, but it cannot know the 1P address corresponding to a remote host because ARP packets are broadcast packets and the router has the function of isolating the broadcast, so the ARP query packets cannot pass through the router and reach the remote destination host. The ARP packets cannot traverse the router and reach the remote destination host. A host on the LAN can configure a default gateway to access the remote host, but hosts are not allowed to configure multiple default gateways. Even if there is another exit router on the LAN, . The host will not send data to the other router, at which point the host's gateway will need to be reconfigured. Proxy ARP can automatically help those hosts on a subnet in this situation to send data to the remote host without reconfiguring the route or even the default gateway.Using proxy ARP can add a separate router to the network without affecting the routing tables of other routers. However, the use of proxy ARP also brings serious shortcomings: using proxy ARP will significantly increase the amount of traffic transmitted in the network segment, and the hosts in the network will remain much larger than normal192168.14 c 00-1B-24-7D-25-04The ARP table will be used to handle the full IP-to-MAC address mapping. For more information on this, you can use the "arp. a" command on hosts with proxy ARP-enabled segments to look at them and see that there are many mapping entries for IP addresses in non-local subnets, and that without proxy ARP enabled, hosts will only have ARP caches for hosts in their local subnets.