Which router is elected as the DR?

Which router is elected as the DR?

Two rules are used to elect a DR and BDR: router with the highest OSPF priority will become a DR. By default, all routers have a priority of 1. if there is a tie, a router with the highest router ID wins the election.

What will an OSPF router prefer to use first as a router ID?

What will an OSPF router prefer to use first as a router ID? Explanation: The first preference for an OSPF router ID is an explicitly configured 32-bit address. This address is not included in the routing table and is not defined by the network command.

What are two purposes of an OSPF router ID?

What are the two purposes of an OSPF router ID? (Choose two.)

• to uniquely identify the router within the OSPF domain.
• to facilitate router participation in the election of the designated router.
• to enable the SPF algorithm to determine the lowest cost path to remote networks.
• to facilitate the establishment of network convergence.

How is router ID determined?

If there is no OSPF Router ID configured, the highest IP address on any of the Routers Loopback Interfaces is selected as the OSPF Router ID. If there is no Loopback Interfaces configured, the highest IP address on its active interfaces is selected as the OSPF Router ID.

What will an OSPF router prefer?

What will an OSPF router prefer to use first as a router ID?

• a loopback interface that is configured with the highest IP address on the router.
• any IP address that is configured using the router-id command.
• the highest active interface IP that is configured on the router.

What are two reasons for creating an OSPF network with multiple areas?

the use of multiple areas OSPF supports the concept of areas to prevent larger routing tables, excessive SPF calculations, and large LSDBs. Only routers within an area share link-state information. This allows OSPF to scale in a hierarchical fashion with all areas that connect to a backbone area.

What algorithm does RIP use?

RIP Protocol Overview The RIP IGP uses the Bellman-Ford, or distance-vector, algorithm to determine the best route to a destination. RIP uses the hop count as the metric. RIP enables hosts and routers to exchange information for computing routes through an IP-based network.

Why do we need router ID in OSPF?

By default, when the OSPF process initializes, it selects the highest IP address on a router as the router ID for the OSPF process. The router ID uniquely identifies a router within an OSPF domain. As explained in Configuring OSPF, OSPF uses the largest IP address configured on the interfaces as its router ID.

What is router ID in BGP?

BGP normally uses the highest IP address assigned to an interface as the router ID. If loopback interfaces are used, the BGP router ID is the highest address assigned to a loopback interface, regardless of the IP addresses assigned to any physical interface.

Do OSPF neighbors show ip?

The Neighbor ID is the router ID of the neighbor router. The router ID is the highest IP address or the highest ip address among loopback addresses (if one is configured) on the Cisco router or can be configured manually by “router-id x.x.x.x”.

Why loopback address is used in OSPF?

Loopback provides redundancy if there are multiple paths to the router and it is also used to identify the router in OSPF because the loopback address is used as the router ID. In the OSPF section, you’ll see routers being identified by their router ID which is the highest loopback address on that router.

Why is loopback address used?

A loopback address is a special IP address, 127.0. 0.1, reserved by InterNIC for use in testing network cards. The loopback address allows for a reliable method of testing the functionality of an Ethernet card and its drivers and software without a physical network.

Why loopback interface is used in BGP?

BGP and Loopback interfaces Using a loopback interface to define neighbors is commonly used with IBGP rather than EBGP. Normally the loopback interface is used to make sure that the IP address of the neighbor stays up and is independent of a hardware that might be flaky.

What is the loopback IP address 127.0 0.1 used for?

127.0. 0.1 is the loopback Internet protocol (IP) address also referred to as the localhost. The address is used to establish an IP connection to the same machine or computer being used by the end-user.

What is the difference between 127.0 0.1 and localhost?

# localhost name resolution is handled within DNS itself. localhost is also called local, usually referred as the local machine, while 127.0. 0.1 is usually considered as local address. It’s very important to know that it will not go through network card when using localhost while it will when using 127.0.

What is the 0.0 0.0 IP address?

In the Internet Protocol Version 4, the address 0.0. 0.0 is a non-routable meta-address used to designate an invalid, unknown or non-applicable target. This address is assigned specific meanings in a number of contexts, such as on clients or on servers.

Is 0.0 0.0 is a valid IP?

It is valid inasmuch as it contains four octets, each within the range 0 through 255 inclusive. However, it is not usable as a real IP address. RFC1700 (a) states that 0.0. 0.0/8 ( 0.

What is 255.255 255.255 used for?

255.255. 255.255 is a special broadcast address, which means “this network”: it lets you send a broadcast packet to the network you’re connected to, without actually caring about its address; in this, is similar to 127.0. 0.1, which is a virtual address meaning “local host”.

Is 255.255 255.255 IP address valid?

A special definition exists for the IP address 255.255. 255.255. It is the broadcast address of the zero network or 0.0. 0.0, which in Internet Protocol standards stands for this network, i.e. the local network.

What is a 255.255 255.255 subnet mask?

A network with a subnet mask of 255.255. 255.255 puts each device inside its own subnet, forcing them to communicate with the router before communicating with any other device.

What is FFFF FFFF MAC address?

ffff. ffff , this is the special reserved MAC address indicating a broadcast frame. This is what makes an ARP Request a broadcast. Had Host A chosen to send this frame using a specific host’s MAC address in the destination, then the ARP request would have been unicast.

What happens to a frame with destination MAC address FFFF FFFF FFFF?

Once the Ethernet frame reaches the network switch, if the destination MAC address is broadcast MAC address (ff:ff:ff:ff:ff:ff), the network switch will forward the Ethernet frame to all its active ports, so that all the devices in the broadcast domain will receive a copy.

What does a destination of FF FF FF FF FF FF signify?

Use FF:FF:FF:FF:FF:FF for both cases. When a device sends a packet to the broadcast MAC address (FF:FF:FF:FF:FF:FF), it is delivered to all stations on the local network. It needs to be used in order for all devices to receive your packet at the datalink layer. For IP, 255.255.

Is ARP layer 2?

ARP is layer 2. The reason being is that a broadcast is sent on layer 2 (data link layer) and ARP will normally not traverse to layer 3 (network layer). However it can provide extra features to the layer 3 protocol. The truth is that not all protocols fit the OSI model exactly, because after all it’s just a model.