From: Brian Dennis (bdennis@internetworkexpert.com)
Date: Sun Oct 26 2003 - 18:33:06 GMT-3
This is very simple to test. Just configure two EIGRP enabled routers with
the same router-id. Then try to advertise external routes from one router to
the other. You will see that the other router will not see the externals.
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
bdennis@internetworkexpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
matijevi@bellsouth.net
Sent: Sunday, October 26, 2003 11:58 AM
To: Brian Dennis; ccielab@groupstudy.com
Subject: Re: OSPF router-id in real lab
Thanks Again Brian,
I will have to play around with this and see it.
Sincerely,
John
----- Original Message -----
From: "Brian Dennis" <bdennis@internetworkexpert.com>
To: <matijevi@bellsouth.net>; <ccielab@groupstudy.com>
Sent: Sunday, October 26, 2003 2:20 PM
Subject: RE: OSPF router-id in real lab
> EIGRP uses router-id's to protect against routing loops for external
routes.
> If a router receives an external route that has the same router-id as its
> own router ID it will reject the route.
>
> Here is a part of an earlier e-mail I sent regarding using 1.1.1.1,
2.2.2.2,
> etc as router-id's:
>
> <Quote>
> In a lab environment where you might have to interact with backbone
routers
> that are shared with other candidates, I would recommend using a router ID
> that is unique. 1.1.1.1, 2.2.2.2 and 3.3.3.3 may not be unique. In a home
> lab they will be unique. In an environment with shared backbone routers
and
> other candidates also doing labs you could possibly end up using the same
> router ID as someone else. To help guard against this possibility pick an
> existing loopback address to hard code as your OSPF, EIGRP and/or BGP
router
> ID or pick X.X.Y.Y where X is your rack number and Y is the device number
> (1=R1, 2=R2, etc).
> </Quote>
>
> Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
> bdennis@internetworkexpert.com
> Toll Free: 877-224-8987
> Direct: 775-745-6404 (Outside the US and Canada)
> Internetwork Expert, Inc.
> http://www.InternetworkExpert.com
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> matijevi@bellsouth.net
> Sent: Sunday, October 26, 2003 10:28 AM
> To: Brian Dennis; 'Shafi, Shahid'; ccielab@groupstudy.com
> Subject: Re: OSPF router-id in real lab
>
> Hello Brian,
> I am curious as to what type of issue an eigrp router-id would solve, I
> havent encountered one yet, but I know that having a router-id for ospf
can
> solve a virtual-link issue, I also know that having a router-id for bgp is
> good for synchronization issue with ospf, so that the bgp router-id should
> match the ospf router-id. Finally, when using router-ids I like to make up
> my own number it doesnt have to be a loopback, I like to use 1.1.1.1 for
> Router 1, 2.2.2.2 for Router 2, etc.
> Sincerely,
> Matijevic
> ----- Original Message -----
> From: "Brian Dennis" <bdennis@internetworkexpert.com>
> To: "'Shafi, Shahid'" <sshafi@qualcomm.com>; <ccielab@groupstudy.com>
> Sent: Sunday, October 26, 2003 1:04 PM
> Subject: RE: OSPF router-id in real lab
>
>
> > Rack1R6(config)#router eigrp 10
> > Rack1R6(config-router)#eigrp router-id ?
> > A.B.C.D EIGRP Router-ID in IP address format
> >
> > Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
> > bdennis@internetworkexpert.com
> > Toll Free: 877-224-8987
> > Direct: 775-745-6404 (Outside the US and Canada)
> > Internetwork Expert, Inc.
> > http://www.InternetworkExpert.com
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> > Shafi, Shahid
> > Sent: Sunday, October 26, 2003 9:54 AM
> > To: Brian Dennis; Alec; ccielab@groupstudy.com
> > Subject: RE: OSPF router-id in real lab
> >
> > Hi Brian,
> >
> > Can you router's id for EIGRP? Never did it and never thought about it??
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> > Brian Dennis
> > Sent: Sunday, October 26, 2003 9:34 AM
> > To: 'Alec'; ccielab@groupstudy.com
> > Subject: RE: OSPF router-id in real lab
> >
> > Yes, use a loopback interface's IP address for your OSPF, BGP and to
> > play it
> > safe, EIGRP router-id.
> >
> > Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
> > bdennis@internetworkexpert.com
> > Toll Free: 877-224-8987
> > Direct: 775-745-6404 (Outside the US and Canada)
> > Internetwork Expert, Inc.
> > http://www.InternetworkExpert.com
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> > Alec
> > Sent: Sunday, October 26, 2003 9:28 AM
> > To: ccielab@groupstudy.com
> > Subject: OSPF router-id in real lab
> >
> > If the lab exam does not require you to configure OSPF router-id, will
> > you
> > make up your own router-id using the highest loopback IP ? It will be
> > easier
> > to more safe for OSPF virtual link configuration. Your comments are
> > welcome.
> >
> > alec
> >
> > _______________________________________________________________________
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