VLSM question
chelseaCA
Registered Users Posts: 2 ■□□□□□□□□□
in CCNA & CCENT
Hi,
I'm preparing for my CCNA ... I cam across a question on book that I wasn't sure if I got it right.
Question : Given network 10.10.4.0/22
R1 fa0/0 – 100 hosts
R2 fa0/0 – 200 hosts
R2 fa0/1 – 50 hosts
Assign network addresses efficiently – ie so that the routers can be configured to the fewest number of routes in their routing tables. Write the network addresses into the diagram below.
MY ANSWER :
R1 fa0/0 – 100 hosts - 10.10.4.0/25
R2 fa0/0 – 200 hosts - 10.10.5.0/24
R2 fa0/1 – 50 hosts - 10.10.6.0/26
btw routers – 2 hosts - 10.10.6.64/30
I was wondering if my IP addressing will result in the fewest number of routes or is there a better solution ?
I'm preparing for my CCNA ... I cam across a question on book that I wasn't sure if I got it right.
Question : Given network 10.10.4.0/22
R1 fa0/0 – 100 hosts
R2 fa0/0 – 200 hosts
R2 fa0/1 – 50 hosts
Assign network addresses efficiently – ie so that the routers can be configured to the fewest number of routes in their routing tables. Write the network addresses into the diagram below.
MY ANSWER :
R1 fa0/0 – 100 hosts - 10.10.4.0/25
R2 fa0/0 – 200 hosts - 10.10.5.0/24
R2 fa0/1 – 50 hosts - 10.10.6.0/26
btw routers – 2 hosts - 10.10.6.64/30
I was wondering if my IP addressing will result in the fewest number of routes or is there a better solution ?
Comments
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RouteMyPacket
Member Posts: 1,104
Ok, so we don't even need a /22 for this IP design but with it we have
10.10.4.0 - 10.10.7.0
Always start with the largest network first so
R2 F0/0 - 200 Hosts
10.10.4.0/24
R1 F0/0 - 100 Hosts
10.10.5.0/25
R2 F0/1 - 50 Hosts
10.10.5.128/26
Serial Link between Routers
10.10.5.192/30
You are going to have "4" networks no matter what you do. The deal is subnet it out so that the routing table has the least amount of routes right? I mean if you are using EIGRP, then
router eigrp 100
network 10.10.0.0
The thing is, to really answer your own question. Fire up GNS3 and create this topology, what does the routing table look like?
My thoughts above would make your routing table look like this
R1
10.0.0.0/8 is variably subnetted, 4 subnets, 4 masks
D 10.10.4.0/24 [90/2172416] via 10.10.5.194, 00:00:23, Serial1/0
C 10.10.5.0/25 is directly connected, FastEthernet0/0
D 10.10.5.128/26 [90/2172416] via 10.10.5.194, 00:00:23, Serial1/0
C 10.10.5.192/30 is directly connected, Serial1/0
R2
10.0.0.0/8 is variably subnetted, 4 subnets, 4 masks
C 10.10.4.0/24 is directly connected, FastEthernet0/0
D 10.10.5.0/25 [90/2172416] via 10.10.5.193, 00:01:10, Serial1/0
C 10.10.5.128/26 is directly connected, FastEthernet0/1
C 10.10.5.192/30 is directly connected, Serial1/0
What would yours look like?Modularity and Design Simplicity:
Think of the 2:00 a.m. test—if you were awakened in the
middle of the night because of a network problem and had to figure out the
traffic flows in your network while you were half asleep, could you do it? -
theodoxa
Member Posts: 1,340 ■■■■□□□□□□
R2 Fa0/0 – 10.10.4.0/24
R2 Fa0/1 – 10.10.5.0/24
SUMMARY ADDRESS placed on R2's Serial Port - 10.10.4.0/23
Serial Link - 10.10.7.252/30 (I used the last possible subnet so that you could add more subnets in between if need be.)
R1 fa0/0 – 10.10.6.0/25R&S: CCENT → CCNA → CCNP → CCIE [ ]
Security: CCNA [ ]
Virtualization: VCA-DCV [ ]