stephtchoko Tue, 05/09/2006 - 08:07
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no auto summary is used with only RIP, EIGRP and IGRPP router.


>if you are using rip version 1(classful protocol), it can't adverstise a subnet mask in the routing.


>if you are using rip version 2 or eigrp (classless protocol), the router will advertise the subnet at classfull boudary.

But with eigrp, you can summarize manually on interface.


Please don't forget to rate this post.


Regards.


carl_townshend Tue, 05/09/2006 - 08:17
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Hi there I will be using eigrp on this router, can you tell me what this will be advertising to my other networks ? will it be 10/8

ankurbhasin Wed, 05/10/2006 - 00:48
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Hi Carl,


Nice to see that you have started appreciating and rating all the posts.


If you are using EIGRP, bydefault auto summarisation is enable so it will advertise as /8 but if you issue a command "no auto summary" under eigrp process it will advertise as /16.


Have a look at this link for clear understanding with topolgy and example for auto summarisation


http://www.cisco.com/warp/customer/103/eigrp-toc.html#auto


HTH, if yes please rate the post.


Ankur

carl_townshend Wed, 05/10/2006 - 01:24
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Hi Ankur


I cant open the doc, thanks, if I advertise a 10.1/16 address on my router and use no auto-sum on that router, another router has learnt this subnet but has auto sum switch on, would the router after that just see the 10/8 because it has auto sum on ?

ankurbhasin Wed, 05/10/2006 - 01:41
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Hi Carl,


EIGRP performs an auto-summarization each time it crosses a border between two different major networks.


So answer to your question is YES the router after that where auto summary is not diabled will advertise it as 10/8.


Try to open the link again as I made it public link now


http://www.cisco.com/warp/public/103/eigrp-toc.html#auto


HTH, if yes please rate all post.


Ankur



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