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Lets suppose we have a computer with three NICs:




We send a packet with the destination IP address being

1) if the default gw is on the 103.55.34/24 network, will the packet be sent through NIC_3 or will the packet be sent through every NIC?

2) If we make an assumption that the whole internet is a one big network and this network network address is, the address looks like a broadcast address for the whole network (for the internet), right?

3) What would be the meaning of a network address like this: (is this correct and if not, why not)

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1 cannot be a network address because a network address has all the host bits set to zero. Since /0 means all the bits are host bits, the only valid /0 network address is – David Schwartz Jan 9 '12 at 1:24
up vote 5 down vote accepted
  1. It will be sent through the first interface in the route table that matches the destination, evaluated in the order static route>route>gateway>metric. If you type route print you'll see something similar to the following:

    Network Destination        Netmask          Gateway       Interface  Metric
    [Loads of entries for your various NICs, routes and static routes]       1
    Default Gateway:

    Indicating that the broadcast/multicast test ping will use your NIC_3

  2. Assuming you had a network, then yes WOULD be the broadcast address. The Internet however is not one big network, it's a series of interconnected completely separate networks (hence inter-net!)

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See my answer here for an explanation of the broadcast address:… – joeqwerty Jan 8 '12 at 23:09

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