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RE: EIGRP Summary-address behavior - LAST response posted 01/09/2003
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RE: "EIGRP summary routes are given an administrative distance value of
5. The administrative distance metric is used to advertise a summary
without installing "IT" in the routing table."
---
Yes, you're right. There is some ambiguity in that sentence. The
solution is in the context, as it is in any language.

If you knew nothing about Cisco IOS, grammatically the
pronoun/antecedent relationship could be between "it" and the antecedent
"administrative distance" or it could be between "it" and "summary." But
in a discussion of IOS routing tables, Cisco (and most other sources)
almost always refer to a *route* being installed in a routing table. So
the summary route is what "it" refers to in the sentence, not the
administrative distance.

HTH

-----Original Message-----
From: cebuano [mailto:cebu2ccie@xxxxxxx] 
Sent: Thursday, January 09, 2003 10:04 AM
To: 'Jonathan V Hays'; ccielab@xxxxxxxxxxxxxx
Cc: amarks@xxxxxxxxx
Subject: RE: EIGRP Summary-address behavior - LAST response


Hi,

I just figured out my own confusion on this topic, and yes, there is
something unclear in my English interpretation of this sentence. If you
speak the language natively, you probably won't see my stumbling block.

Here's a copy/paste of the CCO documentation...
EIGRP summary routes are given an administrative distance value of 5.
The administrative distance metric is used to advertise a summary
without installing "IT" in the routing table.

You see, when I read that word "IT" in this sentence, is it referring to
"metric" or "summary"? In my language, since it is closer in syntax to
the word "summary", then I would conclude "summary" is the NOUN this
"IT" PRONOUN is representing.

Ugghh!!
Another layer of complexity to deal with. I thought after 13 years in
the U.S. that I'd have a very good command of the language. ;-> For
non-English members on this list, allow me to repeat Clinton's words...
"I feel your pain."

Elmer

-----Original Message-----
From: Jonathan V Hays [mailto:jhays@xxxxxxxx] 
Sent: Thursday, January 09, 2003 9:22 AM
To: 'cebuano'
Subject: RE: EIGRP Summary-address behavior

Elmer,

>From what I can see of your posts, your English is much better than 
>most
native speakers!

I don't think that the language is a barrier for non-native speakers.
Speaking as someone who has one attempt under his belt, almost everyone
will be talking to the proctor about ambiguities in the lab test
booklet. Parts of the booklet are very ambiguous and WILL require
clarification. I'm sure Cisco does this deliberately. I even found a
typo in the first couple of pages. 

Ask the proctor. That's what they are there for. If no one is asking
questions they work on their own projects or surf the web or whatever. I
probably went up about 12-15 times and neither proctor seemed
particularly put out about all my questions. A couple of times they
wouldn't answer, saying, "well, that's what you are supposed to figure
out.."

HTH,

Jonathan

-----Original Message-----
From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx] On Behalf Of
cebuano
Sent: Tuesday, January 07, 2003 9:02 PM
To: 'Solomon Ghebremariam'
Cc: ccielab@xxxxxxxxxxxxxx
Subject: RE: EIGRP Summary-address behavior


Hi,
I am not saying I want the summary to Null0 removed. All I'm saying is
if I follow the wording on CCO, that's what is supposed to happen. I
guess this is coming from an Instructor's point of view where a student
reading this would interpret it like it says, that "no summary route is
installed in the route table". So it's safe to say this is not 100%
accurate as documented online. I hope that makes sense. Now my other
concern was that people whose native language is not English might
interpret lab questions/requirements differently and how proctors handle
this situation. Are they considerate or do they take the position that
the candidate is soliciting direct answers to lab questions? I am not
making a big fuss about this though, but considering that each point
earned is important, as a friend put it, a big part of the lab is a test
on a person's comprehension.

I hope I'm making sense.
Thanks.
Elmer


-----Original Message-----
From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx] On Behalf Of
Solomon Ghebremariam
Sent: Tuesday, January 07, 2003 8:00 PM
To: cebuano
Cc: 'Aidan Marks'; ccielab@xxxxxxxxxxxxxx
Subject: RE: EIGRP Summary-address behavior

Elmer
         I am a little confused here. You summarize it for a reason and
why 
do you want to remove the route to Null0 from the table?  Can we achieve
both?

Solomon

At 04:44 PM 1/7/2003 -0500, cebuano wrote:
>Aidan,
>Once again, thanks for redirecting my attention. This is the basis of
my
>original post on CCO....
>http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_command
_
>reference_chapter09186a00800917e8.html#1021694
>
>What I am worried about in the lab is my misinterpretation of
>words/phrases since English is NOT my native tongue. The URL above, to 
>my understanding, says a summary address is NOT installed in the route 
>table (i.e. if I do a "sh ip route" it should NOT be there).
>
>Anyone from non-English background with experience getting
words/phrases
>clarified by the proctor? Were they helpful/snobby/etc...?
>
>Thank you all.
>Elmer
>
>-----Original Message-----
>From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx] On Behalf Of

>Aidan Marks
>Sent: Tuesday, January 07, 2003 5:12 AM
>To: Sage Vadi
>Cc: ccielab@xxxxxxxxxxxxxx
>Subject: Re: EIGRP Summary-address behavior
>
>7200-1#sh ip route eigrp | i Null
>D    172.0.0.0/8 is a summary, 03:27:37, Null0
>7200-1#sh ip route 172.0.0.0
>Routing entry for 172.0.0.0/8, supernet
>    Known via "eigrp 1", distance 5, metric 18944, type internal
>    Redistributing via eigrp 1
>    Routing Descriptor Blocks:
>    * directly connected, via Null0
>        Route metric is 18944, traffic share count is 1
>        Total delay is 80 microseconds, minimum bandwidth is 151515
Kbit
>        Reliability 255/255, minimum MTU 4470 bytes
>        Loading 1/255, Hops 0
>
>[snip]
>
>interface ATM6/0
>   description #TO LS1010-3-0-0#
>   ip address 172.31.69.9 255.255.255.0
>   ip authentication mode eigrp 1 md5
>   ip authentication key-chain eigrp 1 ccie
>   ip summary-address eigrp 1 172.0.0.0 255.0.0.0 5
>   atm pvc 1 0 5 qsaal
>   atm pvc 2 0 16 ilmi
>   atm esi-address 999999999999.00
>   atm ilmi-keepalive
>   atm arp-server nsap 47.111122223333444455556666.666666666666.00
>
>[snip]
>
>router eigrp 1
>   passive-interface default
>   no passive-interface ATM6/0
>   network 172.31.69.0 0.0.0.255
>   no auto-summary
>   no eigrp log-neighbor-changes
>
>[snip]
>
>The creation of a null0 route for an ip eigrp summary address with an
AD
>of
>5 is stated here in the docs, e.g.
>
>http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/
n
>p1_c/1cprt1/1ceigrp.htm
>
>If there is a place on CCO suggesting that the summary address is not
>installed in the RIB when AD < 255, then this is probably a doc bug.
>
>Aidan
>
>At 07:30 PM 7/01/2003, Sage Vadi wrote:
>
> >As Tim indicated,
> >
> >R7#sh ip route 192.168.0.0
> >~cut~
> >* directly connected, via Null0 <--
> >~cut~
> >
> >Q) Why should it show admin distance locally, when it
> >has a directly connected Null0? Have you got this in
> >your lab? Please paste your output and show commands
> >if you do.
> >
> >
> >  --- Aidan Marks <amarks@xxxxxxxxx> wrote: > sh ip
> >route 192.168.0.0 and it will show the
> > > distance in the verbose view.
> > >
> > > At 05:55 PM 7/01/2003, Sage Vadi wrote:
> > >
> > > >Aidan,
> > > >
> > > >Locally on the ABR this is what it gets -
> > > >
> > > >D 192.168.0.0/22 is a summary, 00:52:38, Null0
> > > >
> > > >There is no indication of AD.
> > > >
> > > >I'm going to test with another IOS.
> > > >
> > > >Cheers,
> > > >Sage
> > > >
> > > >
> > > >  --- Aidan Marks <amarks@xxxxxxxxx> wrote: > At
> > > 05:11
> > > >PM 7/01/2003, Sage Vadi wrote:
> > > > >
> > > > > >Elmer/Cebuano,
> > > > > >
> > > > > >On my core router:
> > > > > >D 192.168.0.0/22 [90/2169856] via 116.16.37.2
> > > > > >
> > > > > >On my ABR I have configured:
> > > > > >ip summary-add eigrp 100 192.168.0.0
> > > 255.255.252.0
> > > > > 5
> > > > > >
> > > > > >A# To me it DOES seems that the core router
> > > learns
> > > > > the
> > > > > >summarization as a InternalEIGRP route with AD
> > > of
> > > > > 90.
> > > > > >
> > > > > >This is testing with 12.2(12.5)T, I can also
> > > test
> > > > > with
> > > > > >12.2(10b) if you like.
> > > > > >
> > > > > >Q) Anybody else know why? According to AD
> > > charts
> > > > > >summarized EIGRP routes = 5
> > > > >
> > > > > AD is local.  If you look at the AD of the
> > > summary
> > > > > to null0 via show ip
> > > > > route it should be 5 i.e. "distance 5".  The
> > > other
> > > > > router picks it up as
> > > > > just another EIGRP route (internal) and
> > > therefore
> > > > > gets AD 90 on the other
> > > > > router.
> > > > >
> > > > > Yes?
> > > > >
> > > > > Aidan
> > > > >
> > > > >
> > > > > >Cheers,
> > > > > >Sage
> > > > > >
> > > > > >  --- cebuano <cebu2ccie@xxxxxxx> wrote: >
> > > Hello.
> > > > > > > I'd like to know if the command "ip
> > > > > summary-address
> > > > > > > eigrp" as documented
> > > > > > > on CCO has changed. It is described under
> > > the
> > > > > > > command reference as
> > > > > > > follows.
> > > > > > >
> > > > > > > EIGRP summary routes are given an
> > > administrative
> > > > > > > distance value of 5.
> > > > > > > The administrative distance metric is used
> > > to
> > > > > > > advertise a summary
> > > > > > > without installing it in the routing table.
> > > > > > > But I'm getting two conflicting results.
> > > > > > > 1.    I don't see the admin distance of 5.
> > > > > > > 2.    I see the summary installed in the
> > > routing
> > > > > table.
> > > > > > >
> > > > > > > MC3810a(config-if)#ip summary-address eigrp
> > > 2001
> > > > > > > 150.100.200.0
> > > > > > > 255.255.255.0
> > > > > > >
> > > > > > > MC3810a#ir
> > > > > > >
> > > > > > >      150.100.0.0/16 is variably subnetted, 7 subnets, 2
> > > > > > > masks
> > > > > > > D       150.100.200.0/24 is a summary,
> > > 00:02:41,
> > > > > > > Null0
> > > > > > > C       150.100.200.0/30 is directly
> > > connected,
> > > > > > > Serial0
> > > > > > > D       150.100.100.0/24 [90/2681856] via
> > > > > > > 150.100.200.1, 00:02:07,
> > > > > > > Serial0
> > > > > > > D EX    150.100.2.0/24 [170/2195456] via
> > > > > > > 150.100.200.1, 00:02:07,
> > > > > > > Serial0
> > > > > > > C       150.100.3.0/24 is directly
> > > connected,
> > > > > > > Ethernet0
> > > > > > > D EX    150.100.1.0/24 [170/2195456] via
> > > > > > > 150.100.200.1, 00:02:07,
> > > > > > > Serial0
> > > > > > > D       150.100.10.0/24 [90/2185984] via
> > > > > > > 150.100.200.1, 00:02:09,
> > > > > > > Serial0
> > > > > > >
> > > > > > > MC3810a#sh ip eigrp topo
> > > > > > > IP-EIGRP Topology Table for
> > > > > > > AS(2001)/ID(192.168.254.1)
> > > > > > >
> > > > > > > P 150.100.200.0/24, 1 successors, FD is
> > > 2169856
> > > > > > >          via Summary (2169856/0), Null0
> > > > > > > P 150.100.200.0/30, 1 successors, FD is
> > > 2169856
> > > > > > >          via Connected, Serial0
> > > > > > > P 150.100.100.0/24, 1 successors, FD is
> > > 2681856
> > > > > > >          via 150.100.200.1
> > > (2681856/2169856),
> > > > > > > Serial0
> > > > > > > P 150.100.2.0/24, 1 successors, FD is
> > > 2195456
> > > > > > >          via 150.100.200.1 (2195456/281600),
> > > > > Serial0
> > > > > > > P 150.100.3.0/24, 1 successors, FD is 281600
> > > > > > >          via Connected, Ethernet0
> > > > > > > P 150.100.1.0/24, 1 successors, FD is
> > > 2195456
> > > > > > >          via 150.100.200.1 (2195456/281600),
> > > > > Serial0
> > > > > > > P 150.100.10.0/24, 1 successors, FD is
> > > 2185984
> > > > > > >          via 150.100.200.1 (2185984/176128),
> > > > > Serial0
> > > > > > >
> > > > > > > Any comments?
> > > > > > > Thanks.
> > > > > > > Elmer
> > > > > > > .
> > > > > > >
> > > > >
> > > >
> > >
> > >__________________________________________________________________
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