From: Joseph Brunner (joe@affirmedsystems.com)
Date: Wed Aug 15 2007 - 18:49:31 ART
The network statement is often misunderstood for IGP's. I'll help you out.
The network statement, (UNLIKE BGP) does not advertise the route into the
protocol. Rather, it simply matches ip addresses configured on interfaces.
Once those interfaces are matched by the network statement, eigrp/ospf/rip,
etc. send hellos (in the case of eigrp/ospf) and establish adjacencies. In
the case of RIP, they send routing updates, as rip does not build neighbor
adjacencies.
If you put the network statement under BGP, the route is checked in the
routing table and if it exists, the network IS advertised into BGP
(providing all other bgp conditions are met).
It's a discrete difference, but one worth noting in your studies. As far as
what is actually advertised, well that is the mask configured on the
interface.
-Joe
-----Original Message-----
From: Cecil Wilson [mailto:Cecil.Wilson@flextronics.com]
Sent: Wednesday, August 15, 2007 5:41 PM
To: Joseph Brunner; Narbik Kocharians; Julio Carrasco
Cc: ccielab@groupstudy.com
Subject: RE: Little question about EIGRP summary address
Yes but my point was; there are 2 ways advertize route into EIGRP
or any routing protocol
1. network STM under the routing protocol
2. Redistribute into routing protocol
Cecil G. Wilson
IT Network Services
Office: (901) 215-2710
Cell: (901) 601-6201
cecil.wilson@flextronics.com
-----Original Message-----
From: Joseph Brunner [mailto:joe@affirmedsystems.com]
Sent: Wednesday, August 15, 2007 4:23 PM
To: Cecil Wilson; 'Narbik Kocharians'; 'Julio Carrasco'
Cc: ccielab@groupstudy.com
Subject: RE: Little question about EIGRP summary address
Remember my earlier example?
Ip route 10.10.0.0 255.255.255.0 null0254
Router eigrp 1
Redis static metric 1 1 1 1 1
Int f0/0
Ip summary-address eigrp 1 10.0.0.0 255.0.0.0 5
Now the eigrp route entered the eigrp topology database via the
redistribution from static.
Consider this...
Router#Show ip int brief
R2#sh ip int brief
Interface IP-Address OK? Method Status
Protocol
FastEthernet0/0 173.17.180.3 YES NVRAM up
up
FastEthernet0/1 193.1.180.3 YES NVRAM up
up
Router eigrp 1
Network 10.10.0.0
Int f0/0
Ip summary-address eigrp 1 10.0.0.0 255.0.0.0 5
No interface matches the network command, so the eigrp top db does not
include 10.x.x.x anything, so the summary is not created...
-Joe
-----Original Message-----
From: Cecil Wilson [mailto:Cecil.Wilson@flextronics.com]
Sent: Wednesday, August 15, 2007 5:16 PM
To: Joseph Brunner; Narbik Kocharians; Julio Carrasco
Cc: ccielab@groupstudy.com
Subject: RE: Little question about EIGRP summary address
Seems contratictory by your own eg
-redistribution from another protocol, including static -learned from an
eigrp neighbor -network command matching an up/up interface on the
router.
Cecil G. Wilson
IT Network Services
Office: (901) 215-2710
Cell: (901) 601-6201
cecil.wilson@flextronics.com
-----Original Message-----
From: Joseph Brunner [mailto:joe@affirmedsystems.com]
Sent: Wednesday, August 15, 2007 4:11 PM
To: Cecil Wilson; 'Narbik Kocharians'; 'Julio Carrasco'
Cc: ccielab@groupstudy.com
Subject: RE: Little question about EIGRP summary address
"That is not advertising the routes in eigrp". The "network" command
determines on which interfaces we run eigrp on. Using the network
command with a non-existent interface for the purpose of later
generating a summary does not work.
You can get the constituent routes for creating the summary into eigrp
via
-redistribution from another protocol, including static -learned from an
eigrp neighbor -network command matching an up/up interface on the
router.
-Joe
CCNA
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Cecil Wilson
Sent: Wednesday, August 15, 2007 3:43 PM
To: Narbik Kocharians; Julio Carrasco
Cc: ccielab@groupstudy.com
Subject: RE: Little question about EIGRP summary address
Do you mean advertisizing those routes in Eigrp?
Eg
Router eigrp 100
Net 10.10.10.1 0.0.0.0
Net 10.10.11.1 0.0.0.0
Net 10.10.12.1 0.0.0.0
Int e0/0
Summary eigrp 10.10.0.0 0.0.255.255
Cecil G. Wilson
IT Network Services
Office: (901) 215-2710
Cell: (901) 601-6201
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Narbik Kocharians
Sent: Wednesday, August 15, 2007 1:31 PM
To: Julio Carrasco
Subject: Re: Little question about EIGRP summary address
When ever you need to generate a summary route, those routes need to be
advertised in the specific routing protocol before a summary is
generated.
On 8/15/07, Julio Carrasco <julio.carrasco@ya.com> wrote:
>
> Hello Group,
>
> It4s necessary to configure a component of a summary route under the
> EIGRP proccess to announce the summary address ?, or it is just enough
> having a component of the sumary route in the routing table ?
>
> i.e.
>
> R1 s0/0-------------------------------- s0/0 R2 .2 -------10.0.0.0/24
> lan segment
> .1 1.1.1.0/24 network .2
>
> R2 config:
>
> interface s0/0
> ip address 1.1.1.2 255.255.255.0
> ip summary-address eigrp 10 10.0.0.0 255.0.0.0 !
> router eigrp 10
> network 1.1.1.2 0.0.0.0
> network 10.0.0.2 0.0.0.0 --> Do I need to add this to my config if I
> want
> R2
> to announce the summary route ??
> !
>
> Is this enough so R2 announces 10.0.0.0/8 network to R1,
>
> or do I need to configure a component of the 10.0.0.0/8 network unter
> the EIGRP 10 proccess ??
>
> TIA
> Julio
>
> ______________________________________________________________________
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--Narbik Kocharians
CCIE# 12410 (R&S, SP, Security)
CCSI# 30832
www.Net-WorkBooks.com
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