Table of Contents
What is an inter area route?
Inter area routes are routes that originated in some other OSPF area and are advertised into your area. Inter area routes are advertised with LSA type 3. The type 3 LSA is generated by Border routers. So for example let us consider a Border router that has interfaces in area 0 and in area 5.
What is OSPF summarization?
Route summarization helps reduce OSPF traffic and route computation. OSPF, unlike EIGRP, doesn’t support automatic summarization. Also, unlike EIGRP, where you can summarize routes on every router in an EIGRP network, OSFP can summarize routes only on ABRs and ASBRs.
What does route summarization mean?
Route summarization — also known as route aggregation — is a method to minimize the number of routing tables in an IP network. It consolidates selected multiple routes into a single route advertisement. This differentiates it from flat routing, in which every routing table carries a unique entry for each route.
How do you perform an inter area summarization in OSPF?
Procedure
- Enter system view.
- Enter OSPF view. ospf [ process-id | router-id router-id | vpn-instance vpn-instance-name ] *
- Enter OSPF area view. area area-id.
- Configure ABR route summarization. abr-summary ip-address { mask-length | mask } [ advertise | not-advertise ] [ cost cost-value ]
What is the difference between Inter area and intra area?
Note: Intra-area routes refer to updates that are passed within the area. Inter-area routes refer to updates that are passed between areas. External routes refer to updates passed from another routing protocol into the OSPF domain by the Autonomous System Border Router (ASBR).
What are two features of OSPF inter area route summarization?
What are two features of OSPF interarea route summarization? (Choose two.)
- Route summarization results in high network traffic and router overhead.
- Routes within an area are summarized by the ABR.
- Type 3 and type 5 LSAs are used to propagate summarized routes by default.
- ASBRs perform all OSPF summarization.
What is BGP summarization?
Route Aggregation (RA) also known as BGP Route Summarization is a method to minimize the size of the routing table, announcing the whole address block received from the Regional Internet Registry (RIR) to other ASes.
What is the main difference between ripv1 and RIPv2?
RIP v1 is an older, no longer much used routing protocol. RIP v2 is a classless protocol and it supports classful, variable-length subnet masking (VLSM), CIDR, and route summarization. RIPv2 supports authentication of RIPv2 update messages (MD5 or plain-text).
What are the two reasons why route summarization is important?
Summarization reduces the size of route tables, prevents route table instability due to flapping routes, and reduces the size of routing updates. Summarization enforces router authentication, preventing spurious updates from excessively loading the router.
Where do inter area route summarization be performed in an OSPF network?
There are two types of summarization in OSPF; Inter-Area Summarization and External Summarization. Inter-Area route summarization can only be done on the Area Boarder Router (ABR) and summarize routes from a particular area into the backbone area.
Which protocols are performed at Asbr?
Autonomous system boundary router (ASBR) An autonomous system boundary router is a router that is connected by using more than one routing protocol and that exchanges routing information with routers autonomous systems. ASBRs typically also run an exterior routing protocol (e.g., BGP), or use static routes, or both.
What is ABR OSPF?
An area border router (ABR) is a kind of router that is located near the border between one or more Open Shortest Path First (OSPF) areas. It is used to establish a connection between backbone networks and the OSPF areas.
What are the advantages of using OSPF summarization?
The use of summarization allows a smaller number of route entries in your table, with the added benefits of decreasing the amount of memory used. Specifically, it is much faster for a router to look up a summarized single route to find a match than it is to look up smaller /24 routes, for example.
What is a benefit to route summarization?
The advantages of summarization are that it reduces the number of entries in the route table, which reduces load on the router and network overhead, and hides instability in the system behind the summary, which remains valid even if summarized networks are unavailable.
What is RIPv1 routing protocol?
RIPv1 is a Distance-Vector Routing protocol. RIPv1 is a Classful routing protocol. Classful routing protocols support only the networks which are not subnetted. Classful routing protocols do not send subnet mask information with their routing updates.
How does RIPv1 work?
RIP uses a distance vector algorithm to decide which path to put a packet on to get to its destination. Each RIP router maintains a routing table, which is a list of all the destinations the router knows how to reach. Each router broadcasts its entire routing table to its closest neighbors every 30 seconds.