ON YOUTUBE:
Please find playlist in Hindi & English below:https://www.youtube.com/playlist?list=PL1PiPEQOeKMYqOvyKpym_dkoFY2y5BKt0https://www.youtube.com/playlist?list=PL1PiPEQOeKMY3r659R5gyWt4ScTzpyg6w
About the Protocol
· The algorithm used for this advanced Distance Vector protocol is the Diffusing Update Algorithm.
· The metric is based upon Bandwidth and Delay values.
· For updates, EIGRP uses Update and Query packets that are sent to a multicast address.
· Split horizon and DUAL form the basis of loop prevention for EIGRP.
· EIGRP is a classless routing protocol that is capable of Variable Length Subnet Masking.
· Automatic summarization is on by default, but summarization and filtering can be accomplished anywhere inside the network.
Neighbor Adjacencies
EIGRP forms “neighbor relationships” as a key part of its operation. Hello packets are used to help maintain the relationship. A hold time dictates the assumption that a neighbor is no longer accessible and causes the removal of topology information learned from that neighbor. This hold timer value is reset when any packet is received from the neighbor, not just a Hello packet.
EIGRP uses the network type in order to dictate default Hello and Hold Time values:
· For all point-to-point types – the default Hello is 5 seconds and the default Hold is 15
· For all links with a bandwidth over 1 MB – the default is also 5 and 15 seconds respectively
· For all multi-point links with a bandwidth less than 1 MB – the default Hello is 60 seconds and the default Hold is 180 seconds
Interestingly, these values are carried in the Hello packets themselves and do not need to match in order for an adjacency to form (unlike OSPF).
Reliable Transport
By default, EIGRP sends updates and other information to multicast 224.0.0.10 and the associated multicast MAC address of 01-00-5E-00-00-0A.
For multicast packets that need to be reliably delivered, EIGRP waits until a RTO (retransmission timeout) before beginning a recovery action. This RTO value is based off of the SRTT (smooth round-trip time) for the neighbor. These values can be seen in the show ip eigrp neighbor command.
If the router sends out a reliable packet and does not receive an Acknowledgement from a neighbor, the router informs that neighbor to no longer listen to multicast until it is told to once again. The local router then begins unicasting the update information. Once the router begins unicasting, it will try for 16 times or the expiration of the Hold timer, whichever is greater. It will then reset the neighbor and declare a Retransmission Limit Exceeded error.
Note that not all EIGRP packets follow this reliable routine – just Updates and Queries. Hellos and acknowledgements are examples of packets that are not sent reliably.
EIGRP TUNNING AUTHENTICATION SUMMARIZATION LOAD BALANCING
Taken from wonderful blog : http://cisqueros.blogspot.in/search/label/EIGRP
EIGRP Authentication and some EIGRP “tuning” options
EIGRP Authentication
Like in OSPF – the configuration is done in the Interface Configuration mode. Unlike OSPF – EIGRP supports only MD5 authentication. Set the mode to MD5, even though it’s the default mode on most devices.
This is an example of Frame relay P2P Interface and EIGRP authentication
interface Serial4/1.25 point-to-point
ip address 134.12.122.2 255.255.255.0
ip authentication mode eigrp 100 md5
ip authentication key-chain eigrp 100 EIGRP_CHAIN
frame-relay interface-dlci 201
end
ip address 134.12.122.2 255.255.255.0
ip authentication mode eigrp 100 md5
ip authentication key-chain eigrp 100 EIGRP_CHAIN
frame-relay interface-dlci 201
end
EIGRP: Maximum Hops
Another attribut that can be useful for controlling the routes is the “maximum-hops”. To see each routes hop count:
#show ip route 172.28.185.0
Known via “eigrp 100″, distance 90, metric 2297856, type internal
Redistributing via eigrp 100
Last update from 131.1.12.2 on Serial1/0.12, 00:13:47 ago
Routing Descriptor Blocks:
* 131.1.12.2, from 131.1.12.2, 00:13:47 ago, via Serial1/0.12
Route metric is 2297856, traffic share count is 1
Total delay is 25000 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 12 <– 12 HOPS TO THIS ROUTE!!!
Known via “eigrp 100″, distance 90, metric 2297856, type internal
Redistributing via eigrp 100
Last update from 131.1.12.2 on Serial1/0.12, 00:13:47 ago
Routing Descriptor Blocks:
* 131.1.12.2, from 131.1.12.2, 00:13:47 ago, via Serial1/0.12
Route metric is 2297856, traffic share count is 1
Total delay is 25000 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 12 <– 12 HOPS TO THIS ROUTE!!!
To change the Maximum number of Hops to, for example, 10 (Its 100 by Default):
Cisqueros_1(config-router)#metric maximum-hops 10
EIGRP Administrative Distance
By default EIGRP has the following Administrative Distance values:
170 – External EIGRP Routes
90 – Internal EIGRP Routes
5 – EIGRP Summary Routes
170 – External EIGRP Routes
90 – Internal EIGRP Routes
5 – EIGRP Summary Routes
You can make EIGRP External routes smaller if you need them to not be less prefered then, for example, OSPF, that has AD 110 for External routes:
Cisqueros_1(config-router)#distance eigrp 90 100
EIGRP: Route Summarization
The EIGRP route summarization is done exactly the same like RIP summarization, which makes sense because both protocols have the Distance Vector nature. It can also be done on ANY of the routers within the same EIGRP process, unlike the Link State protocols. It’s done on the Interface using the command:
R2(config-if)#ip summary-address eigrp 100 3.0.0.0 255.0.0.0
And dont be afraid when you see the following message:
*Apr 27 12:53:32.203: %DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 10.1.12.1 (Serial1/0) is resync: summary configured
*Apr 27 12:53:32.203: %DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 10.1.12.1 (Serial1/0) is resync: summary configured
The interface towards Null0 Interface is created automatically. So dont worry, because EIGRP adds this “”discard route” for Loop Avoidance.
Check if “it worked”:
R2#show ip route | i summ
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
D 3.0.0.0/8 is a summary, 00:02:52, Null0
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
D 3.0.0.0/8 is a summary, 00:02:52, Null0
EIGRP Unequal Load Balancing – “variance” command
VARIANCE Command
Variance is a EIGRP feature that enables UNEQUAL load balancing. The only condition that needs to be met is: Paths need to be in the routing table and MEAT THE FEASIBILITY CONDITION!
(Routes ADVERTISED Distance must be lower then the local routes Feasable Distance)
(Routes ADVERTISED Distance must be lower then the local routes Feasable Distance)
Its configured in the EIGRP configuration mode:
(config-router)#variance 2
(config-router)#variance 2
This means that it will include the routes with the metric value up to 2 times greater then the Best Route metric.
EIGRP Default Gateway
The command we all know from OSPF and BGP “default-information originate [always]” will not work in EIGRP. Instead we need to:
Option 1: Configure the static route and redistribute it into the EIGRP
Option 2: Summarize the routes into a Default Route using the previously described summarization method (leak map is added if we wish to inject another routes besides the default route)
Option 1: Configure the static route and redistribute it into the EIGRP
Option 2: Summarize the routes into a Default Route using the previously described summarization method (leak map is added if we wish to inject another routes besides the default route)
R2(config-if)#ip summary-address eigrp 100 0.0.0.0 0.0.0.0 [leak-map ROUTE_MAP]
EIGRP: Timers, k-values, “neighbor” command
EIGRP Timers
The EIGRP timers are configured (a bit non-intuitive commands from my point of view) on the interface towards the EIGRP neighbor:
Set the Hello timer for the EIGRP 100 process:
(config-if)#ip hello-interval eigrp 100 30
Set the Dead timer for the EIGRP 100 process:
(config-if)#ip hold-time eigrp 100 120
Check the configured Timers using the command:
#show ip eigrp interface static
EIGRP “show neighbors” command
Cisqueros1#show ip eigrp neighbors
EIGRP-IPv4 Neighbors for AS(100)
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
0 10.1.12.2 Se1/0.12 115 00:10:04 26 200 0 32
EIGRP-IPv4 Neighbors for AS(100)
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
0 10.1.12.2 Se1/0.12 115 00:10:04 26 200 0 32
How to interpret this output:
H – The order in which neighbors were found, starting from 0
Address – Neighbors IP
Interface – from where we see the Neighbor
Holdtime – how long we have left before we declare the neighbor down (if no Hello is received)
Uptime – How long since we first found out about the neighbor
SRTT – Smooth Round Trip Time. time required for EIGRP packet to reach the neighbor and receive the ACK
RTO – Retransmission Timeout – how long before the packet is re-transmitted
Q Count – Number of packets in the EIGRP queue
SeqNum – Sequence Number of the last received EIGRP packet
EIGRP Metric – K Values
5 K-Values are used to calculate the EIGRP Metric. It´s pretty important to know at least which one is which of the K values:
K1 – Bandwidt
K2 – Load
K3 – Delay
K4 – Reliability
K5 – Reliability
K2 – Load
K3 – Delay
K4 – Reliability
K5 – Reliability
Metric = (K1*BW + (K2*BW)/(256-Load) + K3*Delay) * 256
By default K2 = K4 = K5 = 0, so the Metric depends on the Bandwidth and Delay only
If you need the EIGRP Metric to depend on some other values the command is (ToS should be left 0):
(config-router)#metric weight tos k1 k2 k3 k4 k5
¡¡¡BE CAREFULL BECAUSE K VALUES NEED TO MATCH BETWEEN THE EIGRP NEIGHBORS!!!
l
an network is 192.168.1.0/24 and network between R2 & R4 is 10.1.24.0/30
network between R1 & R3 is 10.1.13.0/30
!
hostname R1
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
ip cef
!
key chain rat
key 1
key-string cisco
accept-lifetime 21:00:00 Jun 11 2013 12:00:00 Jul 15 2013
send-lifetime 21:00:00 Jun 11 2013 12:00:00 Jul 15 2013
!
!
interface FastEthernet0/0
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0
ip address 10.1.15.1 255.255.255.252
clock rate 2000000
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/1
bandwidth 5000
ip address 10.1.13.1 255.255.255.252
ip summary-address eigrp 100 5.5.5.0 255.255.255.248 5
clock rate 2000000
!
interface Serial0/2
ip address 10.1.12.1 255.255.255.252
ip authentication mode eigrp 100 md5
ip authentication key-chain eigrp 100 rat
ip summary-address eigrp 100 5.5.5.0 255.255.255.248 5
clock rate 2000000
!
interface Serial0/3
no ip address
shutdown
clock rate 2000000
!
router eigrp 100
variance 3
redistribute ospf 1 metric 1 1 1 1 1
network 10.0.0.0
no auto-summary
!
router ospf 1
log-adjacency-changes
network 10.1.15.0 0.0.0.3 area 0
!
ip forward-protocol nd
ip route 10.0.0.0 255.0.0.0 10.1.15.0
!
!
no ip http server
no ip http secure-server
!
control-plane
!
!
line con 0
exec-timeout 0 0
logging synchronous
line aux 0
line vty 0 4
login
!
!
end
===================================================================
!
hostname R2
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
ip cef
!
no ip domain lookup
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
!
!
!
!
!
key chain rat
key 1
key-string cisco
accept-lifetime 21:00:00 Jun 11 2013 12:00:00 Jul 15 2013
send-lifetime 21:00:00 Jun 11 2013 12:00:00 Jul 15 2013
!
interface FastEthernet0/0
ip address 192.168.1.2 255.255.255.0
ip authentication mode eigrp 100 md5
ip authentication key-chain eigrp 100 rat
duplex auto
speed auto
!
interface Serial0/0
ip address 10.1.12.2 255.255.255.252
ip authentication mode eigrp 100 md5
ip authentication key-chain eigrp 100 rat
clock rate 2000000
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/1
ip address 10.1.24.1 255.255.255.252
clock rate 2000000
!
router eigrp 100
variance 3
redistribute rip metric 1 1 1 1 1
passive-interface default
no passive-interface FastEthernet0/0
no passive-interface Serial0/0
network 10.0.0.0
network 192.168.1.0
no auto-summary
!
router rip
version 2
network 10.0.0.0
no auto-summary
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
!
line con 0
exec-timeout 0 0
logging synchronous
line aux 0
line vty 0 4
login
!
!
end
========================================================================
!
hostname R3
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
ip cef
!
!
!
!
no ip domain lookup
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3!
key chain rat
key 1
key-string cisco
accept-lifetime 21:00:00 Jun 11 2013 12:00:00 Jul 15 2013
send-lifetime 21:00:00 Jun 11 2013 12:00:00 Jul 15 2013
!
!
!
!
interface FastEthernet0/0
ip address 192.168.1.3 255.255.255.0
ip authentication mode eigrp 100 md5
ip authentication key-chain eigrp 100 rat
duplex auto
speed auto
!
interface Serial0/0
ip address 10.1.13.2 255.255.255.252
ip authentication mode eigrp 100 md5
ip authentication key-chain eigrp 100 rat
clock rate 2000000
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/1
no ip address
shutdown
clock rate 2000000
!
router eigrp 100
variance 3
network 10.0.0.0
network 192.168.1.0
no auto-summary
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
!
!
line con 0
exec-timeout 0 0
logging synchronous
line aux 0
line vty 0 4
login
!
!
end
====================================================================
!
hostname R4
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
ip cef
!
interface Loopback1
ip address 4.4.4.4 255.255.255.255
!
interface Serial0/1
ip address 10.1.24.2 255.255.255.252
clock rate 2000000
!
router rip
version 2
network 4.0.0.0
network 10.0.0.0
no auto-summary
!
ip forward-protocol nd
!
!
end
=========================================================================
!
hostname R5
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
memory-size iomem 5
ip cef
!
!
!
!!
!
interface Loopback1
no ip address
!
interface Loopback2
ip address 5.5.5.2 255.255.255.255
!
interface Loopback3
ip address 5.5.5.3 255.255.255.255
!
interface Loopback4
ip address 5.5.5.4 255.255.255.255
!
interface FastEthernet0/0
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0
ip address 10.1.15.2 255.255.255.252
clock rate 2000000
!
router ospf 1
log-adjacency-changes
network 5.5.5.1 0.0.0.0 area 0
network 5.5.5.2 0.0.0.0 area 0
network 5.5.5.3 0.0.0.0 area 0
network 5.5.5.4 0.0.0.0 area 0
network 10.1.15.0 0.0.0.3 area 0
!
end
No comments:
Post a Comment