Chapter 4

    Cards (36)

    • Static routes
      Commonly implemented on a network, even when there is a dynamic routing protocol configured
    • Types of static routes
      • Standard static route
      • Default static route
      • Floating static route
      • Summary static route
    • Static routes
      Configured using the ip route and ipv6 route global configuration commands
    • Next-hop options when configuring a static route
      • Next-hop route (only the next-hop IP address is specified)
      • Directly connected static route (only the router exit interface is specified)
      • Fully specified static route (the next-hop IP address and exit interface are specified)
    • Configuring IPv4 static routes
      ip route network-address subnet-mask { ip-address | exit-intf [ip-address]} [distance]
    • Configuring IPv6 static routes
      ipv6 route ipv6-prefix/prefix-length {ipv6-address | exit-intf [ipv6-address]} [distance]
    • Dual-stack topology

      • No static routes configured for either IPv4 or IPv6
    • R1 can ping R2, but cannot ping the R3 LAN
    • Configuring IPv4 next-hop static route on R1
      1. ip route 172.16.1.0 255.255.255.0 172.16.2.2
      2. ip route 192.168.1.0 255.255.255.0 172.16.2.2
      3. ip route 192.168.2.0 255.255.255.0 172.16.2.2
    • Configuring IPv6 next-hop static route on R1
      1. ipv6 route 2001:db8:acad:1::/64 2001:db8:acad:2::2
      2. ipv6 route 2001:db8:cafe:1::/64 2001:db8:acad:2::2
      3. ipv6 route 2001:db8:cafe:2::/64 2001:db8:acad:2::2
    • Configuring IPv4 directly connected static route on R1
      1. ip route 172.16.1.0 255.255.255.0 s0/1/0
      2. ip route 192.168.1.0 255.255.255.0 s0/1/0
      3. ip route 192.168.2.0 255.255.255.0 s0/1/0
    • Configuring IPv6 directly connected static route on R1
      1. ipv6 route 2001:db8:acad:1::/64 s0/1/0
      2. ipv6 route 2001:db8:cafe:1::/64 s0/1/0
      3. ipv6 route 2001:db8:cafe:2::/64 s0/1/0
    • Fully specified static route
      Both the exit interface and the next-hop IP address are specified
    • When the exit interface is an Ethernet network, it is recommended to use a fully specified static route that includes both the exit interface and the next-hop address
    • Configuring IPv6 fully specified static route on R1
      ipv6 route 2001:db8:acad:1::/64 s0/1/0 2001:db8:acad:2::2
    • Link-local addresses

      Not contained in the IPv6 routing table, only unique on a given link or network
    • When using an IPv6 link-local address as the next-hop address, a fully specified static route must be used
    • Commands to verify static routes
      • show ip route static
      • show ip route network
      • show running-config | section ip route
    • Default route
      A static route that matches all packets, used as the Gateway of Last Resort
    • Routers commonly use default routes that are either configured locally or learned from another router
    • Default static routes are commonly used when connecting an edge router to a service provider network, or a stub router
    • Default static route
      A static route that matches all packets. A single default route represents any network that is not in the routing table.
    • Default static routes
      • Commonly used when connecting an edge router to a service provider network, or a stub router (a router with only one upstream neighbor router)
    • Configure IPv4 default static route

      ip route 0.0.0.0 0.0.0.0 {ip-address | exit-intf}
    • Configure IPv6 default static route
      ipv6 route ::/0 {ipv6-address | exit-intf}
    • Configure IPv4 default static route
      • ip route 0.0.0.0 0.0.0.0 172.16.2.2
    • Configure IPv6 default static route
      • ipv6 route ::/0 2001:db8:acad:2::2
    • Floating static route
      A static route used to provide a backup path to a primary static or dynamic route. The floating static route is only used when the primary route is not available.
    • Administrative distance
      Represents the trustworthiness of a route. If multiple paths to the destination exist, the router will choose the path with the lowest administrative distance.
    • Configure IPv4 floating static route
      ip route 0.0.0.0 0.0.0.0 10.10.10.2 5
    • Configure IPv6 floating static route
      ipv6 route ::/0 2001:db8:feed:10::2 5
    • Host route
      An IPv4 address with a 32-bit mask, or an IPv6 address with a 128-bit mask
    • Ways a host route can be added to the routing table
      • Automatically installed when an IP address is configured on the router
      • Configured as a static host route
      • Host route automatically obtained through other methods
    • Configure IPv4 static host route
      ip route 209.165.200.238 255.255.255.255 198.51.100.2
    • Configure IPv6 static host route
      ipv6 route 2001:db8:acad:2::238/128 2001:db8:acad:1::2
    • Configure IPv6 static host route with link-local next-hop
      ipv6 route 2001:db8:acad:2::238/128 fe80::1 GigabitEthernet0/0