Default gateways serve an important role in
The following illustration shows the role played by two default gateways (IP routers) for two networks: Network 1 and Network 2.
Role of default gatewaysIn order for Host A on Network 1 to communicate with Host B on Network 2, Host A first checks its routing table to see if a specific route to Host B exists. If there is no specific route to Host B, Host A forwards its
The same principle applies if Host B is sending to Host A. Without a specific route to Host A, Host B forwards any
Default gateways are important to make IP routing work efficiently. In most cases, the router that acts as the default gateway for
TCP/IP hosts rely on default gateways for most of their communication needs with hosts on remote network segments. In this way, individual hosts are freed of the burden of having to maintain extensive and continuously updated knowledge about individual remote IP network segments. Only the router that acts as the default gateway needs to maintain this level of routing knowledge to reach other remote network segments in the larger internetwork.
If the default gateway fails, communication beyond the local network segment may be impaired. To prevent this, you can use the Advanced
If you have multiple interfaces and you configure a default gateway for each interface,
If multiple interfaces of the same speed have the same lowest interface metric, then, based upon the binding order, the default gateway of the first network adapter is used. The default gateway for the second network adapter is used when the first is unavailable.
In previous versions of
The automatic determination of the interface metric is enabled by default through the Automatic metric check box on the IP Settings tab on the advanced properties of the Internet Protocol (TCP/IP) protocol.
You can disable the automatic determination of the interface metric and type a new value for the interface metric.