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[CCNP 642-902 Router ] [ EIGRP OSPF Redistribution Sim ] CCNP Sim 문제 본문

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[CCNP 642-902 Router ] [ EIGRP OSPF Redistribution Sim ] CCNP Sim 문제

sungchan41 2014. 1. 6. 08:19

Question: (Hope someone will contribute the detailed requirement of this sim!)


% EIGPR AS Number 와 R2,R3 interface 의 bandwidth 가 변경 되어 출제되는 경우도 있습니다!!


Some information I have gathered so far:

R2 is an ASBR for EIGRP 100 and OSPF AREA 24

R3 is an ASBR for EIGRP 100 and OSPF AREA 34

[note: so there are TWO separate areas on TWO separate ASBRS

thus you need to do redistribution on R2 and R3

R1 is ONLY in EIGRP 100, and is THE ONLY router you can ping from. R4 has a loopback interface that must be pinged from R1.

R4 is running OSPF and has redundant link to EIGRP network over R3 router.

The requirement of this sim is traffic from R1 should go to the most optimal route to reach 172.16.100.0/24 network

Notice: You should make a ping from R1 to 172.16.100.1 network to make sure everything is working correctly.



Answer and Explanation:

Thanks to POONAM who send us the topology and configuration. She got 100% on EIGRP-OSPF lab so this solution is perfect! Please say thank to him and others who contribute this lab-sim!

SOLUTION from POONAM

First we need to find out 5 parameters (Bandwidth, Delay, Reliability, Load, MTU) of the s0/0/0 interface (the interface of R2 connected to R4) for redistribution :

R2#show interface s0/0/0

Write down these 5 parameters, notice that we have to divide the Delay by 10 because the metric unit is in tens of microsecond. For example, we get Bandwidth=1544 Kbit, Delay=20000 us, Reliability=255, Load=1, MTU=1500 bytes then we would redistribute as follows:

R2#config terminal

R2(config)# router ospf 1

R2(config-router)# redistribute eigrp 100 metric-type 1 subnets

R2(config-router)#exit

R2(config-router)#router eigrp 100

R2(config-router)#redistribute ospf 1 metric 1544 2000 255 1 1500

 

(Notice: In fact, these parameters are just used for reference and we can use other parameters with no problem. Also, a candidate said that the simulator didn’t accept the Bandwidth of 1544; in that case, we can use a lower value, like 128.

If the delay is 20000us then we need to divide it by 10, that is 20000 / 10 = 2000)

Note: “usec” here does not mean microsecond (which is 1/1000 milliseconds) but means millisecond. In short usec = msec. I don’t know why they use the word “usec” here but just think it is “msec” (According to this link: http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094cb7.shtml#eigrpmetrics: “The delay as shown in the show ip eigrp topology or show interface commands is in microseconds”)

For R3 we use the show interface fa0/0 to get 5 parameters too

R3#show interface fa0/0

For example we get Bandwidth=10000 Kbit, Delay=1000 us, Reliability=255, Load=1, MTU=1500 bytes

R3#config terminal

R3(config)#router ospf 1

R3(config-router)#redistribute eigrp 100 metric-type 1 subnets

R3(config)#exit

R3(config-router)#router eigrp 100

R3(config-router)#redistribute ospf 1 metric 10000 100 255 1 1500

Finally you should try to “show ip route” to see the 172.16.100.1 network (the network behind R4) in the routing table of R1 and make a ping from R1 to this network.

Note: If the link between R2 and R3 is FastEthernet link, we must put the command below under EIGRP process to make traffic from R1 to go through R3 (R1 -> R2 -> R3 -> R4), which is better than R1 -> R2 -> R4.

R2(config-router)# distance eigrp 90 105

This command sets the Administrative Distance of all EIGRP internal routes to 90 and all EIGRP external routes to 105, which is smaller than the Administrative Distance of OSPF (110) -> the link between R2 & R3 will be preferred to the serial link between R2 & R4.

Maybe the “copy running-config startup-config” command will not work in this lab so don’t worry, just skip it.

Note: Please check the OSPF process numbers first before typing these commands. Maybe they are not “ospf 1″ like above. 출처 : www.digitaltut.com

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