Hi
my self is jitendera kumar sinha.i think you are not
confused but forgetting some thing about eigrp.yeah thats
true eigrp support 100(by default) and 255 max hoop count.
now according to the your problem you have 115 router(wright?)
now one thing is that which you forget is redstribution.this
is the beauty of eigrp is that it can comunicate two diffent
nrtwork haveing diffrent autonomas sustem number.

now question is that what is redistribution-answer is 
when there is larger network than to reduse routing overhead
redistribution is applied

now let there is two network N1 and N2
now on N1
router(config)#router eigrp 10
         "    #network 192.168.0.0
now on N2
router(config)#router eigrp 11
         "    #network 193.168.0.0
NOW WHAt do you notice that router of network N1 have as
number 10 and router of network N2 have the as number 11
then what do you think will they communicate
answer is no.
so to start communication between them we have to configure
redistribution)

now question is that how and where we implement redistribution

here it is
go to router N1
router(config)#eigrp 10
              #network 192.168.0.0
              #redistribute eigrp 11 metric ****5****
****5***** that mean you have to enter here metric value of
eigrp 
that is bandwidth.load relablity,mtu and delay(this is not
in sequenced manner you have to enter it in sequantial)

ok now what to do divide your network in two half and give
thesese two network diffrent AS number and aplly
redistribution between these network.

eigrp has atomatical detect hoop count.
no need to congigure it can be done by#no root
symmetrization(i am not confirmed) 75% sure
but it will be cause of routing loop
so avoid this
your part b answer is describe in redistribution configuration
so i think no need of that

Thanks
hope this article help you lots
jitendera sinha

Hi Jitendera, If i m not wrong, then in EIGRP, Metric weight
is set to K1(Bandwidth)=1, K2(Delay)=0, K3(Reliability)=1,
K4(Load)=0, K5(MTU)=0. This is default setting for EIGRP. 

I knew about it from ICND 2 cisco press book. 

Three more questions - 

a) If we change the K value (I mean metric weight)on a
router what will happen???

b) When redistribution is necessary in EIGRP. Is there any
condition for that???

c) What is reference bandwidth for metric calculation in
EIGRP. As we know, in OSPF, on a CISCO router reference
bandwidth is 10Mbps.

hi sahin.now i am trying to giver your all three question but one thing is necessary to know that what is default. default is that which can be configurable. now in the eigrp determination of path done by cost. that is cost==10^8/bandwidth now the path which have best cost is selected as best path that is the path have lower cost selected as best path. one point is noticeable that eigrp use only bandwidth and delay to path calculation .mtu is never used for path calculation but it is a important parameter for eigrp related command. how to configure bandwidth of eigrp Set the bandwidth on your interfaces using the bandwidth command Router (config-if)# bandwidth XX(if you want bandwidth 5600 simply write 56 not 5600) this is the command by which you can configure your bandwidth now back to your first question. 1 now you are going to change the metric value that is "k" the what happen here is the answer k=ad value/bandwidth(Wright)for eigrp ok ad value is constant(let) now you can change only bandwidth value now as we discus earlier that path determination is based on bandwidth so as you increase the bandwidth cost decrees then it will be selected as best path. and if you decrease then cost increases then it kept in to routing table.

Now your second question’s have written earlier that to reduce routing overload we need redistribution in another way we can say that in the larg network we need redistribution.

Now yours 3rd questions
 
Frankly speaking I don’t know but it may be 10 mbps

hi sahin.now i am trying to giver your all three question but one thing is necessary to know that what is default. default is that which can be configurable. now in the eigrp determination of path done by cost. that is cost==10^8/bandwidth now the path which have best cost is selected as best path that is the path have lower cost selected as best path. one point is noticeable that eigrp use only bandwidth and delay to path calculation .mtu is never used for path calculation but it is a important parameter for eigrp related command. how to configure bandwidth of eigrp Set the bandwidth on your interfaces using the bandwidth command Router (config-if)# bandwidth XX(if you want bandwidth 5600 simply write 56 not 5600) this is the command by which you can configure your bandwidth now back to your first question. 1 now you are going to change the metric value that is "k" the what happen here is the answer k=ad value/bandwidth(Wright)for eigrp ok ad value is constant(let) now you can change only bandwidth value now as we discus earlier that path determination is based on bandwidth so as you increase the bandwidth cost decrees then it will be selected as best path. and if you decrease then cost increases then it kept in to routing table.

Now your second question’s have written earlier that to reduce routing overload we need redistribution in another way we can say that in the large network we need redistribution.

Now yours 3rd questions
 
Frankly speaking I don’t know

hi sahin.now i am trying to giver your all three question but one thing is necessary to know that what is default. default is that which can be configurable. now in the eigrp determination of path done by cost. that is cost==10^8/bandwidth now the path which have best cost is selected as best path that is the path have lower cost selected as best path. one point is noticeable that eigrp use only bandwidth and delay to path calculation .mtu is never used for path calculation but it is a important parameter for eigrp related command. how to configure bandwidth of eigrp Set the bandwidth on your interfaces using the bandwidth command Router (config-if)# bandwidth XX(if you want bandwidth 5600 simply write 56 not 5600) this is the command by which you can configure your bandwidth now back to your first question. 1 now you are going to change the metric value that is "k" the what happen here is the answer k=ad value/bandwidth(Wright)for eigrp ok ad value is constant(let) now you can change only bandwidth value now as we discus earlier that path determination is based on bandwidth so as you increase the bandwidth cost decrees then it will be selected as best path. and if you decrease then cost increases then it kept in to routing table.

Now your second question’s have written earlier that to reduce routing overload we need redistribution in another way we can say that in the large network we need redistribution.

Now yours 3rd questions
 
Frankly speaking I don’t know