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New Member

summarizing addresses

Can anyone please tell me how much I can summarize the and networks, I am using eigrp and want to summarize the best I can, would I just advertise the network i eigrp, and could I summarize this down to say a /26 on my serial interface ?

Cisco Employee

Re: summarizing addresses


the 27 mask would give you 32 address blocks. What about and Were you really referring to /27 or rather to /26?

If the latter, you could summarize the two first blocks (0/26 and 64/26) to

Hope this helps,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
México móvil: +52 1 55 8312 4915
Cisco México 
Paseo de la Reforma 222 Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
New Member

Re: summarizing addresses

Hi there, thanks for your help, your right, It should of said /26 not /27, how would I summarize these then ? how did you work it out to a /25, can you show me how you did this ?

thanks a million


New Member

Re: summarizing addresses

can anyone help me on this ?

New Member

Re: summarizing addresses

Hi Carl...

it is easy to summarise.

in summarisation you have to check the same number of high order bits.

so in binary it would be

so if you check that in fourth octet only first bit is same in all the address,so in subnet mask we can on the first bit to summarise all the subnets.

so summarised address will be...

Hope it hepls.

P.S:- Rate the post if find it useful.



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