RIP & EIGRP

Done

RIP (Routing Information Protocol)

It uses Distance Vector algorithm (”routing by rumor”)

The metric is Hop Count

The maximum hop count is 15, anything greater than that will be unreachable

Has three versions:
- RIPv1 and RIPv2, which use IPv4
- RIPng (RIP Next Generation), which uses IPv6

There is two types of messages:
- Request: Ask the neighbor router to send its routing table
- Response: Sends its routing table to the neighbor device

RIP-enabled devices send messages every 30 seconds

RIPv1 vs RIPv2

RIPv1:

Only advertises classful addresses

Doesn`t support VLSM, CIDR

Doesn`t include subnet masks in the messages, it assumes the subnet mask of a neighbor router by the first octet (classful)

Messages are sent via Broadcast

RIPv2:

Supports VLSM, CIDR

Advertises the subnet mask of the destination addresses of its routing table

Advertises via Multicast 224.0.0.9

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REMEMBERING: Broadcast messages are delivered to all devices on the same LAN (Broadcast Domain) Multicast messages are delivered only to devices that have joined that multicast group.

Configuration

Enter RIP configuration mode

configure terminal
router rip

Select the RIP version

version 2 // In RIP configuration mode

Disable Auto-summary

This function saves bites in the wire by not sending the mask

no auto-summary // In RIP configuration mode

Specify which networks advertise

This command specifies which interface it will activate RIP and also what networks it will advertise

network {subnet ID}  // In RIP configuration mode

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It will resolve it to a classful ip address, activating rip in all the interfaces in that class range and advertises all networks in that same range.

Disable RIP messages on an interface

passive-interface {interface}  // IN RIP CONFIGURATION MODE

Share the same default route

default-information originate  // In RIP configuration mode

Change the number of maximum similar paths in the routing table

maximum-paths {1-32}  // In RIP configuration mode

Change de Administrative Distance

distance {value} // In RIP configuration mode

EIGRP

It was Cisco`s Proprietary routing protocol, however Cisco`s published it openly so other vendors could implement it. But, it is still not widely used, being still considered Cisco`s protocol.

Is is considered an advanced Distance Vector routing protocol.

It is much faster than RIP in reacting to changes

It doesn`t have a hop count limit of 15

Sends messages to the multicast address 224.0.0.10 (1 more than RIPv2)

Is the only IGP that can perform unequal-cost load-balancing (by default it performs ECMP over 4 paths like RIP). In other words, it can send load-balance traffic between links that have different costs.

Enter EIGRP Configuration mode

configure terminal
router eigrp {as value}

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IMPORTANT: You need to specify the autonomous system, organization, number. And all the routers that will use that EIGRP will need to have the same value, similar to the domain in VTP.

Disable Auto-Summary

It is the same as RIP, which advertises and assumes only classful IP Addresses are used, so you better disable it.

router eigrp 1
no auto-summary

Network command

It works the same as in RIP and OSPF. It will specify the range of IP Addresses, and any interface in that range will both send EIGRP messages and will advertise their subnet/network.

However, you can use a WILDMASK here (The inverse of a subnet mask), to specify only that range of ip address instead of a range which defaults to the classful rules of /8, /16 and /24.

configure terminal
router eigrp 1
no auto-summary
network 192.168.2.0 0.0.0.255

Each router in a EIGRP Autonomous System will have a unique Router ID which can be defined as followed:

Manual Configuration (eigrp router-id value)

Highest IP Address on a loopback interface (Router`s virtual interface)

Highest IP Address on a physical interface

See EIGRP Neighbors - Adjancies

show ip eigrp neighbors

See all the routes advertised (including the ones that were not selected)

show ip eigrp topology

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REMEMBER: Metric = Bandwidth of the Slowest Link + delay of all links The delay is a number that is related to an interface bandwidth.

Terminology

Feasible Distance: This router`s metric value to the route`s destination

Reported Distance (Advertised Distance): The neighbor`s metric value to the route`s destination (Basically, the neighbor`s feasible distance)

Successor: Best candidate to route in the routing table, the one with the lowest metric

Feasible Sucessor: It a alternate route to the destination (not the best route). It must meet the feasibility condition: its reported distance must be lower than the successor’s feasible distance

Unequal-Cost Load-Balancing