Calcul du metric EIGRP

Le calcul du metric EIGRP est le résultat composite de 5 paramétrés :

  • La bande passante
  • La Charge
  • Le Délais
  • La Fiabilité

Par défaut, K1 et K3 sont à 1, et le reste à zéro, réduisant la formule à :

R1#show ip protocols
Routing Protocol is "eigrp 100"
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Default networks flagged in outgoing updates
  Default networks accepted from incoming updates
  EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
  EIGRP maximum hopcount 100
  EIGRP maximum metric variance 1
  Redistributing: eigrp 100, eigrp 300
  EIGRP NSF-aware route hold timer is 240s
  Automatic network summarization is not in effect
  Maximum path: 4
  Routing for Networks:
    1.1.1.1/32
    10.1.111.1/32
  Routing Information Sources:
    Gateway         Distance      Last Update
    10.1.111.111          90      00:42:05
  Distance: internal 90 external 170

Exemple :

Pour atteindre l`IP 111.1.1.111 depuis R1, il nécessaire de traverser l`interface fa0/0 de R1 et l`interface Lo0 de BB1

R1#show int fa0/0 | inc MTU
  MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
BB1#show interfaces lo0 | inc MTU
  MTU 1514 bytes, BW 8000000 Kbit, DLY 5000 usec,

 

  • la plus petite bande passante est utilisée (celle de fa0/0)
  • les delay sont additionnés

METRIC = 256 * (10000000 / 100000) + ( (5000 + 100) / 10 )
METRIC = 156160

R1#show ip route 111.1.1.0
Routing entry for 111.1.1.0/24
  Known via "eigrp 100", distance 90, metric 156160, type internal
  Redistributing via eigrp 100, eigrp 300
  Advertised by eigrp 300
  Last update from 10.1.111.111 on FastEthernet0/0, 00:31:18 ago
  Routing Descriptor Blocks:
  * 10.1.111.111, from 10.1.111.111, 00:31:18 ago, via FastEthernet0/0
      Route metric is 156160, traffic share count is 1
      Total delay is 5100 microseconds, minimum bandwidth is 100000 Kbit
      Reliability 255/255, minimum MTU 1500 bytes
      Loading 1/255, Hops 1

Pour ne plus prendre en considération le délai, il suffit de mettre K3 a 0 :

R1(config)#router eigrp 100
R1(config-router)#metric weights 0 1 0 0 0 0

*Feb 19 21:02:49.767: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.1.111.111 (FastEt
hernet0/0) is down: metric changed
*Feb 19 21:02:50.351: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.1.111.111 (FastEt
hernet0/0) is down: K-value mismatch

 

Vérifications :

R1#show ip protocols
Routing Protocol is "eigrp 100"
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Default networks flagged in outgoing updates
  Default networks accepted from incoming updates
  EIGRP metric weight K1=1, K2=0, K3=0, K4=0, K5=0
  EIGRP maximum hopcount 100
  EIGRP maximum metric variance 1
  Redistributing: eigrp 100, eigrp 300
  EIGRP NSF-aware route hold timer is 240s
  Automatic network summarization is not in effect
  Maximum path: 4
  Routing for Networks:
    1.1.1.1/32
    10.1.111.1/32
  Routing Information Sources:
    Gateway         Distance      Last Update
    10.1.111.111          90      00:00:11
  Distance: internal 90 external 170
R1#show ip route eigrp 100
     111.0.0.0/24 is subnetted, 3 subnets
D       111.2.2.0 [90/25600] via 10.1.111.111, 00:02:17, FastEthernet0/0
D       111.1.1.0 [90/25600] via 10.1.111.111, 00:02:17, FastEthernet0/0
D       111.0.0.0 [90/25600] via 10.1.111.111, 00:02:17, FastEthernet0/0
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