From: Mark Stephanus Chandra (mark.chandra@gmail.com)
Date: Wed Aug 13 2008 - 07:56:46 ART
HI Fahad,
Thanks for your Input,
I immediately test on my lab environment, but the result is not what We
Expect, please correct me if I'm Wrong.
The topology is like this :
R1 ------ R3 ----- SW2
1. R1 summary Route 212.18.0.0 255.255.0.0 distance 5
and get this route : D 212.18.0.0/16 is a summary, 00:11:41, Null0 (As we
agree that this route AD should be 5 right ? How to verify this ?)
2. R3 get the summary route with AD 90
D 212.18.0.0/16 [90/8234010] via 162.1.13.1, 00:17:40, Serial1/1
3. And I summary this route to SW2 with this command :
ip summary-address eigrp 200 212.18.0.0 255.255.0.0 5
IF I get you right, this command will over rule the summary address D
212.18.0.0/16 [90/8234010] via 162.1.13.1, 00:17:40, Serial1/1
as this summary will install in the routing table with AD 5 right ? The
route in R3 should be D 212.18.0.0/16 is a summary, 00:11:41, Null0
but As I see, the route is not change :
D 212.18.0.0/16 [90/8234010] via 162.1.13.1, 00:17:40, Serial1/1
DO I Miss something here ?
Thanks a lot for looking into this.
Regards
Mark Stephanus Chandra
IT Consultant
From: Fahad Khan [mailto:fahad.khan@gmail.com]
Sent: Wednesday, August 13, 2008 3:16 PM
To: Mark Stephanus Chandra
Cc: Hong Chan; Hobbs; ccielab@groupstudy.com
Subject: Re: Eigrp SUmmarization
Dear Mark,
I posted regarding this query on19th july,08. This "distance" keyword in "ip
summary-address eigrp" command is used to modify the AD of the discard route
populated in the routing table when a router sends a summary route to its
neighbour and absolutely not for modifying the AD of the routes in
neighbour's routing table. consider this scenario,
1.1.1.1/24----(lo0)
R1(s1/0)10.0.0.1-------10.0.0.2(s1/0)R2(s1/1)11.0.0.1-----11.0.0.2(s1/0)R3
|
(lo0)1.1.2.1/24
-R1 is sending summary (1.0.0.0/8) to R2 through "ip summ-add" command
-R1 will have discard route to null0 in its routing table
-R2 gets this summary with AD of 90 from R1 ( as its normal eigrp update for
R2's perception)
-if R2 needs to generate summary route(1.0.0.0/8) towards R3 through "ip
summ-add" command, then here comes a conflit, R2 will create discard route
entry in its routing table for 1.0.0.0/8 since it has deafilt AD of 5 and
that will suppress the summary update got from R1. In order to prevent this
behaivour , increase the AD of summary route more than 90 when configuring
on R2 for R3. Then , R2 wont be having any discard route in its routing
table and R3 will be having a summary in its routing table as 1.0.0.0/8 and
will be able to ping 1.1.2.1 <http://1.1.2.1/> and 1.1.1.1
<http://1.1.1.1/> .
-This is how we can play with discard route through modifing AD.
HTH
On 8/13/08, Mark Stephanus Chandra <mark.chandra@gmail.com> wrote:
Hi Hong,
The problem is, The Distance is not propagated to the neighbor router.
Just like I said, whatever your distance is, the AD on your neighbor would
still the same, which is 90
On Wed, Aug 13, 2008 at 12:54 PM, Hong Chan <howard.chan34@gmail.com> wrote:
> For my understanding, the distance is used if you 2 router doing
> summarization and you don't want to load balance them. you can adjust 1 of
> the summary route to be larger than 90 on 1 of the routers which perform
the
> summarization. Then the router should only have 1 summary route, which is
> learned from another summary router.
> Please correct me if I am wrong
> 2008/8/13 Mark Stephanus Chandra <mark.chandra@gmail.com>
>
>> Hi expert,
>>
>>
>>
>> I'm wondering about EIGRP summarization,
>>
>>
>>
>> IP summary address eigrp 200 192.168.10.0 255.255.255.0 160
>>
>>
>>
>> The distance value seems don't do anything.
>>
>>
>>
>> I check in my neighboring router, I have the eigrp summarization route
>> with
>> AD 90 (Internal).
>>
>>
>>
>> So what the distance is for in eigrp summarization
>>
>>
>>
>> Thanks
>>
>>
>>
>> Regards
>>
>>
>>
>> Mark Stephanus Chandra
>> IT Consultant
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
>> _______________________________________________________________________
>> Subscription information may be found at:
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>>
>>
>>
>>
>>
>>
>>
>>
>
-- Mark Stephanus Chandra IT ConsultantBlogs and organic groups at http://www.ccie.net
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