Data flow for 1 PC w/ 2 NICs
From a testing perspective, if a PC has 2 NIC's, each configured for a different subnet, does traffic actually cross the LAN since each unique MAC is represented by a unique IP according to its ARP cache? Would not the destination network need to be resolved by a router? I guess a better question would be, is there an application that could actually choose a specfic NIC on which to send traffic. Is there? Question is based on VM images and would like to create the least number of VM images as possible to simulate a network.
Software/Hardware used:
Software/Hardware used:
ASKED:
March 23, 2009 8:20 PM
UPDATED:
March 24, 2009 2:39 PM
Answer Wiki:
Depends on the client device routing table. If you put a route on each interface for a particular network in the OS then it would choose the appropriate interface route. If the traffic is destined for the same subnet as a NIC has, then the traffic would go out that NIC. Traffic from both NICs could go to a common router if that router is listening on both subnets. You will need to provide more information for us to help you design a network using VM's.
To see all answers submitted to the Answer Wiki: View Answer History.
use traceroute to find out which way the packets are traveling for a specific IP address.
Do a “route print” (Windows) or netstat -rn (unix/Linux) to find out which NIC cards are used for what. Traffic directly for the subnets on the 2 NIC’s will go to the appropriate one; but make sure you don’t have a default route on BOTH NIC’s. route delete… can get rid of the undesired one; and if you like you can route add to force downstream traffic to choose one or the other.