Routing Fundamentals Flashcards
What is routing?
The process of forwarding packets between networks.
What are the general rules of routing?
- Routers will only use routes with reachable next hops
- Routers will only use the best route
- Routes must be believable and still active
- Router will only accept routes that match it’s own active protocols
What is a connected route?
The router has a network on it’s interface and is able to figure out what network is on the cable that’s connected to the interface
What is a Static route?
A route that is manually setup within the router.
What is a Dynamic Route?
A route that was learned through one of the routing protocols
What is administrative distance?
The feature that routers use in order to select the best path when there are two or more different routes to the same destination from two different routing protocols also defines the reliability of a routing protocol
What is the administrative distance range?
0-255
What is the connected protocol administrative distance?
0
What is the static route protocol administrative distance?
1
What is the EIRGP(internal) protocol administrative distance?
90
What is the OSPF protocol administrative distance?
110
What is the IS-IS protocol administrative distance?
115
What is the RIP protocol administrative distance?
120
What is the EIRGP(EXTERNAL) protocol administrative distance?
170
What is the IBGP/EBGP protocol administrative distance?
200/20
What is the unreachable administrative distance?
255
What is an Autonomous System?
Collection of networks under 1 administrative authority
What is IGP?
Interior Gateway Protocol
Provides reachability information WITHIN an autonomous system
What is EGP?
Exterior Gateway Protocol
Provides reachability information BETWEEN DIFFERENT autonomous systems
What are the 4 categories of routing protocols?
Distance Vector - IGP
Link State - IGP
Advance Distance Vector(Hypbrid) - IGP
Path Vector - EGP
What are the 4 routing update types?
Incremental Update - Only changes are sent in the update
Full update- Full routing table is sent in the update
Periodic Update - Sent in the specified time interval
Triggered update - Sent whenever change is detected
Triggered and Incremental are basically the same thing.
What is a routing metric?
Metrics are used to determine whether one route should be chosen over another. The metric depends on the routing protocol architecture.
Rip Metric - Hop Count
OSPF Metric - Link Bandwidth
EIGRP - Composite formula utilizing link bandwidth and delay
Where is basic info of a statis route?
- Used in small networks
- No dynamic fail over
- Information on destination prefix and gateway are required
What is a floating static route?
A manually set static route with a higher administrative distance than another more preferred route.
Command:
Router(config)#ip route
What is Router on a stick?
Term frequently used to describe a setup up that consists of a router and switch connected using one Ethernet link configured as an 802.1q trunk link. In this setup, the switch is configured with multiple VLANs and the router performs all routing between the different networks/VLANs.
What do you have to do to a switch for it to route?
Enable routing on the switch
Switch(config)#ip routing
What are the characteristics of RIPv2?
IGP/ Distance Vector - no neighbor relations
Metric = Hop Count
Capable of load balacing 6 equal cost paths
Sends out routing updates every 30 seconds
What multicast addresses does RIP utilize for IPv4 and IPv6?
IPv4 - 224.0.0.9
IPv6 - FF02::9
What are the IGP dynamic routing configuration steps?
- Makes sure there is at least one functional interface with an i[ address on the device.
- Enable routing protocol
- Define networks for which the routing protocol will be active
- Enable authentication for the routing protocol (optional)
What is the command for a IPv6 address?
Router(config-if)#i[v6 address <address> / </address>
Is IPv6 enabled by default on routers or multi-layer switches?
No
Use the command
Router(config)# ipv6 unicast-routing
Permits router to send ICMPv6 Router Advertisements
Allows IPv6 routing between connected interfaces
Allows operation of IPv6 routing protocols.
How do you set a IPv6 static route?
Router(config)#ipv6 route
How do you configure a default IPv6 Route?
Router(config)# ipv6 route ::/0 2001:aa:bb:cc::77
