Re: Eigrp SUmmarization

From: Fahad Khan (fahad.khan@gmail.com)
Date: Sat Aug 16 2008 - 04:53:36 ART

Yes, I was trying to convey such thing.

On 8/16/08, Hobbs <deadheadblues@gmail.com> wrote:
>
> Hi Mark, I think another example might explain. This time we want to remove
> the null route completely. I also don't think you can generate a summary you
> already have learned, it doesn't work for me just like it doesn't work for
> you.
>
> We can work with different prefix-lengths. Suppose I have the following
> topology:
>
> R5---->R2---->R1<----R4
> |
> R3
>
> R5 has a loopback 192.168.1.1/32.
> R4 has two loopbacks: 192.168.1.2/32 and 192.168.1.3/32.
> R2 sends summary to R1 192.168.0.0/22
> R1 wants to send a summary for these R4 routes to R3 of 192.168.168.1.0/30.
> R1 now has null route with a longer match than the summary from R2:
>
> R1#show ip route | inc 192.168.1|192.168.0.0
> 192.168.1.0/24 is variably subnetted, 4 subnets, 2 masks
> D 192.168.1.0/30 is a summary, 00:06:33, Null0
> D 192.168.1.3/32 [90/2297856] via 172.12.14.4, 00:06:33, Serial1/1
> D 192.168.1.2/32 [90/2297856] via 172.12.14.4, 00:06:33, Serial1/1
> D 192.168.1.4/32 [90/2297856] via 172.12.14.4, 00:06:33, Serial1/1
> D 192.168.0.0/22 [90/2809856] via 172.12.123.2, 00:06:33, Serial1/0
>
> R3#ping 192.168.1.1
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:
> U.U.U
>
> Now when R3 sends a packet to 192.168.1.1 it matches the null route not
> the summary from R2. Even in this case we can't change the AD to just be
> higher than 90 because longer match still rules over AD. So we need to
> change the AD to 255 to make it disappear completely.
>
> R1(config)#int s1/0
> R1(config-if)#ip summary-address eigrp 1 192.168.1.0 255.255.255.252 255
>
> R1#clear ip route *
> R1#show ip route | inc 192.168.1|192.168.0.0
> 192.168.1.0/32 is subnetted, 3 subnets
> D 192.168.1.3 [90/2297856] via 172.12.14.4, 00:00:02, Serial1/1
> D 192.168.1.2 [90/2297856] via 172.12.14.4, 00:00:02, Serial1/1
> D 192.168.1.4 [90/2297856] via 172.12.14.4, 00:00:02, Serial1/1
> D 192.168.0.0/22 [90/2809856] via 172.12.123.2, 00:00:02, Serial1/0
> R1#
>
> R3#ping 192.168.1.1
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:
> !!!!!
> Success rate is 100 percent (5/5), round-trip min/avg/max = 20/53/168 ms
>
> does that explain it?
>
>
> On Thu, Aug 14, 2008 at 7:33 PM, Mark Stephanus Chandra <
> mark.chandra@gmail.com> wrote:
>
>> Sorry Fahad,
>>
>>
>>
>> But even I Do with ip summar address AD of 5, the summary route form R1
>> won't dissapear either.
>>
>>
>>
>>
>>
>>
>>
>> Regards
>>
>>
>>
>> *Mark Stephanus Chandra
>> *IT Consultant
>>
>>
>>
>>
>>
>> *From:* Fahad Khan [mailto:fahad.khan@gmail.com]
>> *Sent:* Thursday, August 14, 2008 1:47 PM
>>
>> *To:* Mark Stephanus Chandra
>> *Cc:* Hong Chan; Hobbs; ccielab@groupstudy.com
>> *Subject:* Re: Eigrp SUmmarization
>>
>>
>>
>> Yeah , thats wat exacty u want to achieve. The discard route in R3 routing
>> table disappears when you increase the AD value in "ip summary-address" on
>> R3.
>>
>>
>>
>> regards,
>>
>>
>>
>> On 8/13/08, *Mark Stephanus Chandra* <mark.chandra@gmail.com> wrote:
>>
>> Hi Fahad,
>>
>>
>>
>> I have tried what you told me to do, but summary address from R1 still
>> installed on R3 and it's not defeated by discard route with AD 5.
>>
>>
>>
>> Somehow the discard route AD5 doesn't appear in the routing table.
>>
>>
>>
>> R3 route :
>>
>>
>>
>> D 212.18.0.0/16 [90/8234010] via 162.1.13.1, 00:46:06, Serial1/1
>>
>> C 212.18.5.0/24 is directly connected, Loopback2
>>
>> C 212.18.4.0/24 is directly connected, Loopback1
>>
>>
>>
>> interface FastEthernet0/0
>>
>> ip address 162.1.38.3 255.255.255.0
>>
>> ip summary-address eigrp 200 212.18.0.0 255.255.0.0 91
>>
>> duplex half
>>
>> end
>>
>>
>>
>>
>>
>> and r3 still be able to ping loopback on R1 since Summary address not
>> defeated and stil in the routing table.
>>
>>
>>
>> Sw2 also can ping all the loopback since R3 loopback have specific route
>> and route to R1 is a summary
>>
>>
>>
>> Regards
>>
>>
>>
>> *Mark Stephanus Chandra
>> *IT Consultant
>>
>>
>>
>> *From:* Fahad Khan [mailto:fahad.khan@gmail.com]
>> *Sent:* Wednesday, August 13, 2008 8:00 PM
>>
>>
>> *To:* Mark Stephanus Chandra
>> *Cc:* Hong Chan; Hobbs; ccielab@groupstudy.com
>> *Subject:* Re: Eigrp SUmmarization
>>
>>
>>
>> OK e.g,R1 is having loopbacks as 212.18.0.1/24,
>> 212.18.1.1/24....212.18.10.1/24 and u created the summary address as
>> 212.18.0.0/16 and R3 is having loopbacks as
>> 212.18.11.1/24,212.18.12.1/24....212.18.20.1/24 and u send the summary as
>> 212.18.0.0/16 towards SW2 , now you wont ping 212.18.0.1 or any of the
>> loopbacks configured on R1 since a discard route (having AD of 5) would be
>> there on R3 suppressing the summary(AD 90) got from R1. I hope you are
>> getting me now. Now inorder to prevent this situation you need to increase
>> the AD of discard route from 90 so that R3 can have summary form R1. that
>> why u have the keyword in this "ip summary-add" command.SW2 would be able to
>> ping all the loopbacks on R3 and R1.
>>
>>
>>
>> HTH
>>
>>
>>
>>
>>
>> what i am saying , the summary which R3 is getting from R1 is actually a
>> simple EIGRP update for SW2 which R3 is sending to SW2. But if R3 will
>> generate its own summary (of specific routes that are on R3 other then that
>> on R1 but having the same major net i.e 212.18) to SW2 but "ip-summary add"
>> command on R3, then R3 will create a discard route Ok i will try to
>> make an exmaple for you later.
>>
>>
>>
>> On 8/13/08, *Mark Stephanus Chandra* <mark.chandra@gmail.com> wrote:
>>
>> Yes Fahad
>>
>>
>>
>> The SW 2 getting the summary address from R3 which R3 getting this from
>> R1.
>>
>>
>>
>> I still don't understand what this distance going to effect.
>>
>>
>>
>> COuld you give me live example ?
>>
>>
>>
>> Sorry to bother you like this.
>>
>>
>>
>> Regards
>>
>>
>>
>> *Mark Stephanus Chandra
>> *IT Consultant
>>
>>
>>
>>
>>
>> *From:* Fahad Khan [mailto:fahad.khan@gmail.com]
>> *Sent:* Wednesday, August 13, 2008 6:56 PM
>>
>>
>> *To:* Mark Stephanus Chandra
>> *Cc:* Hong Chan; Hobbs; ccielab@groupstudy.com
>> *Subject:* Re: Eigrp SUmmarization
>>
>>
>>
>> Remeber! this route is not due to the "ip-summary address eigrp" command
>> used on R3. just do one thing, delete the "ip summary-add" commnad on R3 for
>> SW2, then check whether are u getting the same route in SW2?
>>
>> On 8/13/08, *Mark Stephanus Chandra* <mark.chandra@gmail.com> wrote:
>>
>> I'm Getting summary route with internal AD
>>
>>
>>
>> D 212.18.0.0/16 [90/8236570] via 162.1.38.3, 00:00:33, FastEthernet0/0
>>
>>
>>
>> Regards
>>
>>
>>
>> *Mark Stephanus Chandra
>> *IT Consultant
>>
>>
>>
>> *From:* Fahad Khan [mailto:fahad.khan@gmail.com]
>> *Sent:* Wednesday, August 13, 2008 6:23 PM
>>
>>
>> *To:* Mark Stephanus Chandra
>> *Cc:* Hong Chan; Hobbs; ccielab@groupstudy.com
>> *Subject:* Re: Eigrp SUmmarization
>>
>>
>>
>> Dear Mark,
>>
>>
>>
>> First tell me quickly, are u getting summary route installed in SW2's
>> routing table? and what is that route?
>>
>>
>>
>> On 8/13/08, *Mark Stephanus Chandra* <mark.chandra@gmail.com> wrote:
>>
>> 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) <http://1.1.1.1/24----%28lo0%29>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 1.0.0.0/8and will be able to ping
>> 1.1.2.1 and 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
>> >>
>> >> _______________________________________________________________________
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>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >
>>
>>
>> --
>> Mark Stephanus Chandra
>> IT Consultant
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
>> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>>
>>
>>
>>
>>
>> --
>> *FAHAD KHAN**
>>
>> BE Computer Systems NED,
>>
>> CCNA,CCDA,CCNP,FOUNDFE,CLSE,QOS,JNCIA,JNCIS,MCP,CCIE (Written)
>>
>> Systems Support Engineer, Premier Systems (Pvt) limited,
>>
>> Karachi, Pakistan
>>
>> 92-321-2370510.*
>>
>>
>>
>>
>> --
>> *FAHAD KHAN**
>>
>> BE Computer Systems NED,
>>
>> CCNA,CCDA,CCNP,FOUNDFE,CLSE,QOS,JNCIA,JNCIS,MCP,CCIE (Written)
>>
>> Systems Support Engineer, Premier Systems (Pvt) limited,
>>
>> Karachi, Pakistan
>>
>> 92-321-2370510.*
>>
>>
>>
>>
>> --
>> *FAHAD KHAN**
>>
>> BE Computer Systems NED,
>>
>> CCNA,CCDA,CCNP,FOUNDFE,CLSE,QOS,JNCIA,JNCIS,MCP,CCIE (Written)
>>
>> Systems Support Engineer, Premier Systems (Pvt) limited,
>>
>> Karachi, Pakistan
>>
>> 92-321-2370510.*
>>
>>
>>
>>
>> --
>> FAHAD KHAN
>>
>> BE Computer Systems NED,
>>
>> CCNA,CCDA,CCNP,FOUNDFE,CLSE,QOS,JNCIA,JNCIS,MCP,CCIE (Written)
>>
>> Systems Support Engineer, Premier Systems (Pvt) limited,
>>
>> Karachi, Pakistan
>>
>> 92-321-2370510.
>>
>>
>>
>>
>> --
>> *FAHAD KHAN**
>>
>> BE Computer Systems NED,
>>
>> CCNA,CCDA,CCNP,FOUNDFE,CLSE,QOS,JNCIA,JNCIS,MCP,CCIE (Written)
>>
>> Systems Support Engineer, Premier Systems (Pvt) limited,
>>
>> Karachi, Pakistan
>>
>> 92-321-2370510.*
>>
>
> 

-- 
*FAHAD KHAN

BE Computer Systems NED,

CCNA,CCDA,CCNP,FOUNDFE,CLSE,QOS,JNCIA,JNCIS,MCP,CCIE  (Written)

Systems Support Engineer, Premier Systems (Pvt) limited,

Karachi, Pakistan

92-321-2370510.*

Blogs and organic groups at http://www.ccie.net

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