Configuring Routing Interfaces 859switch management. The loopback interface IP address is a good choice forcommunicating with the switch in these cases because the loopback interfacecannot go down when the switch is powered on and operational.Tunnel InterfaceTunnels can be used in networks that support both IPv6 and IPv4. The tunnelallows non-contiguous IPv6 networks to be connected over an IPv4infrastructure.Default Routing Interface ValuesBy default, no routing interfaces are configured.When you create a VLAN, no IP address is configured, and DHCP is disabled.After you configure an IP address, routing is automatically enabled on theinterface, and the interface has the default configuration shown inTable 30-1.Most interface configuration parameters are not applicable to loopbackinterfaces, so you cannot change the default values. However, when you createa loopback interface, the default values are similar to those of VLAN routinginterfaces, as Table 30-1 shows. Is this true - the show interface loopbackcommand lists all these features and values, but it looks like there is no way toconfigure them.Table 30-1. VLAN Routing Interface and Loopback Interface DefaultsParameter Default ValueForward Net Directed Broadcasts DisabledEncapsulation Type Ethernet (N/A for loopbacks)Proxy Arp EnabledLocal Proxy Arp DisabledIP MTU 1500Bandwidth Not configured.Destination Unreachables EnabledICMP Redirects Enabled
