From: Logan, Harold (loganh@xxxxxxxxx)
Date: Mon Jun 03 2002 - 11:32:07 GMT-3
I think that's a sound practice regardless. OSPF and BGP aren't the only pitfal
ls that can cause trouble if you create a loopback midway through the lab. By r
eading the whole thing and creating (or at least being aware of) all the loopba
ck interfaces, you'll also know what networks need to be filtered if you end up
doing a redistribute connected, or when you activate a routing protocol that d
oesn't let you use a mask in the network commands, ie rip or igrp.
Assuming that 1. the router-id command is permitted and 2. all of the routers a
re running an ios that supports the router-id command, then Nick's approach of
hard-coding the router id when ospf is first configured sounds like the safest
way to do it.
Hal
> -----Original Message-----
> From: Denise Donohue [mailto:denise@dtxnet.com]
> Sent: Tuesday, May 21, 2002 8:40 PM
> To: 'Nick Shah'
> Cc: ccielab@groupstudy.com
> Subject: RE: OSPF - practice approach (pseudo loopbacks)
>
>
> Sorry for the misunderstanding. I was responding to what I read into
> Bruce's answer. If you weren't allowed to nail the router
> id, then that's a
> good argument for at least skimming the entire test before
> starting. Then
> you could go ahead and put on any loopbacks before
> configuring the routing
> protocols.
>
> -----Original Message-----
> From: Nick Shah [mailto:nshah@connect.com.au]
> Sent: Sunday, June 02, 2002 8:33 PM
> To: Denise Donohue; 'Bruce Williams'; 'Michael Snyder'
> Cc: ccielab@groupstudy.com
> Subject: Re: OSPF - practice approach (pseudo loopbacks)
>
>
> Denise,
>
> Of course what you are telling is true, however, the discussion was
> revolving around 2 aspects, one being that *what if* we are
> not allowed to
> use pseudo router id's ?
>
> Nick
> -----Original Message-----
> From: Denise Donohue <denise@dtxnet.com>
> To: 'Nick Shah' <nshah@connect.com.au>; 'Bruce Williams'
> <bruce@williamsnetworking.com>; 'Michael Snyder' <msnyder@ldd.net>
> Cc: ccielab@groupstudy.com <ccielab@groupstudy.com>
> Date: Monday, 3 June 2002 8:22
> Subject: RE: OSPF - practice approach (pseudo loopbacks)
>
>
> >One thing you should know about all this is that the router
> id doesn't have
> >to be an actual interface address on the router, in OSPF or
> in BGP either.
> >It's just a number the router uses to identify itself. You
> can use 1.1.1.1
> >etc without creating any new interfaces.
> >
> >-----Original Message-----
> >From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On
> Behalf Of
> >Nick Shah
> >Sent: Sunday, June 02, 2002 2:42 PM
> >To: Bruce Williams; Michael Snyder
> >Cc: ccielab@groupstudy.com
> >Subject: Re: OSPF - practice approach (pseudo loopbacks)
> >
> >
> >Guys,
> >
> >There are 2 approaches here ...We are..
> >
> >* allowed/disallowed to use our own router-id's (what we
> call pseudo id's)
> >* allowed/disallowed to *nail* the router-id's
> >
> >In the first scenario, if allowed we can use router-id
> 1.1.1.1 (for RTRA)
> >and so on. This obviously has its benefits (easy
> recognizability for one,
> >stability of virtual links etc. the other).
> >
> >Even if we are not allowed to do the first, we can still do
> the second,
> how.
> >Say for example, after turning on OSPF processes on all of
> the routers in
> >the lab, see what has been selected in terms of router-ids,
> say RtrA is
> >192.168.250.250, still nail it as, router-id 192.168.250.250. This is
> better
> >because now whatever new loopbacks are added or if new ip
> addresses are
> >assigned at a later stage in lab, the router id wont change
> on reload.
> >
> >What do you think of this ?
> >
> >rgds
> >Nick
> >----- Original Message -----
> >From: "Bruce Williams" <bruce@williamsnetworking.com>
> >To: "Michael Snyder" <msnyder@ldd.net>
> >Cc: <ccielab@groupstudy.com>
> >Sent: Monday, June 03, 2002 1:03 AM
> >Subject: RE: OSPF - practice approach
> >
> >
> >> That is what I figured. I will ask the proctor, but at
> least I know that
> I
> >> am not the only one who does that. I guess that is all I was really
> >looking
> >> for. I kind of wanted to see if anyone else did the same
> thing and you
> >> validated that for me.
> >>
> >> Thanks,
> >>
> >> Bruce
> >>
> >> -----Original Message-----
> >> From: Michael Snyder [mailto:msnyder@ldd.net]
> >> Sent: Sunday, June 02, 2002 10:38 AM
> >> To: 'Bruce Williams'
> >> Cc: ccielab@groupstudy.com
> >> Subject: RE: OSPF - practice approach
> >>
> >>
> >> Save that question for the proctor. I suspect each test would be
> >> different. Aren't you assuming all tests have ospf? Heck
> you may get
> >> ISIS.
> >>
> >> The short answer is that we don't know, and if we did
> know, we couldn't
> >> tell you.
> >>
> >> BTW, I do the same thing, it seems to be a standard
> practice. Here's my
> >> routing table from last night's lab.
> >>
> >> Gateway of last resort is not set
> >>
> >> 1.0.0.0 0xFFFFFF00 is subnetted, 1 subnets
> >> C 1.1.1.0 is directly connected, Loopback0
> >> 2.0.0.0 0xFFFFFF00 is subnetted, 1 subnets
> >> D 2.2.2.0 [90/2809856] via 10.1.1.26, 14:30:33, Serial0
> >> 3.0.0.0 0xFFFFFF00 is subnetted, 1 subnets
> >> D 3.3.3.0 [90/2297856] via 10.1.1.2, 14:30:24, Serial1
> >> 4.0.0.0 0xFFFFFF00 is subnetted, 1 subnets
> >> D 4.4.4.0 [90/3321856] via 10.1.1.26, 07:42:02, Serial0
> >> 5.0.0.0 0xFFFFFF00 is subnetted, 1 subnets
> >> D 5.5.5.0 [90/2297856] via 10.1.1.26, 14:30:33, Serial0
> >> 6.0.0.0 0xFFFFFF00 is subnetted, 1 subnets
> >> D 6.6.6.0 [90/3321856] via 10.1.1.2, 07:42:02, Serial1
> >> 7.0.0.0 0xFFFFFF00 is subnetted, 1 subnets
> >> D 7.7.7.0 [90/2809856] via 10.1.1.2, 14:30:24, Serial1
> >> 10.0.0.0 0xFFFFFFFC is subnetted, 7 subnets
> >> D 10.1.1.8 [90/3193856] via 10.1.1.2, 14:30:24, Serial1
> >> D 10.1.1.12 [90/3705856] via 10.1.1.2, 07:42:02, Serial1
> >> [90/3705856] via 10.1.1.26, 07:42:02, Serial0
> >> C 10.1.1.0 is directly connected, Serial1
> >> D 10.1.1.4 [90/2681856] via 10.1.1.2, 14:31:24, Serial1
> >> C 10.1.1.24 is directly connected, Serial0
> >> D 10.1.1.16 [90/3193856] via 10.1.1.26, 14:31:34, Serial0
> >> D 10.1.1.20 [90/2681856] via 10.1.1.26, 14:31:34, Serial0
> >>
> >>
> >> -----Original Message-----
> >> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]
> On Behalf Of
> >> Bruce Williams
> >> Sent: Sunday, June 02, 2002 8:47 AM
> >> To: Andre Riscalla; Michael Popovich
> >> Cc: Bauer, Rick; 'Jerry Haverkos'; Ademola Osindero;
> >> ccielab@groupstudy.com
> >> Subject: RE: OSPF - practice approach
> >>
> >> I know this is a queston for the proctor, but I am curious
> now. In the
> >> lab,
> >> do you know if you are allowed to create your own
> loopbacks and make
> >> those
> >> loopbacks your router ids. For example, could I create a
> loopback with
> >> addresss 1.1.1.1 for R1 and 2.2.2.2 for R2 etc?
> >>
> >> Bruce Williams
> >>
> >> -----Original Message-----
> >> From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com]On Behalf Of
> >> Andre Riscalla
> >> Sent: Saturday, June 01, 2002 11:41 PM
> >> To: Michael Popovich
> >> Cc: Bauer, Rick; 'Jerry Haverkos'; Ademola Osindero;
> >> ccielab@groupstudy.com
> >> Subject: Re: OSPF - practice approach
> >>
> >>
> >> In that case, i think a good practice is to nail it down
> and configure a
> >> router-id under each and every OSPF process... if it's not
> otherwise
> >> specified in the lab, you can do it.
> >>
> >> AR-
> >>
> >> On Wed, 29 May 2002, Michael Popovich wrote:
> >>
> >> > You'll just need to remember the rules that if you have loopback
> >> interfaces
> >> > the highest IP wins. If you add them later you'll need
> to change the
> >> > configurations for the virtual link or upon a reboot it
> is broken.
> >> >
> >> > MP
> >> > ----- Original Message -----
> >> > From: "Bauer, Rick" <BAUERR@toysrus.com>
> >> > To: "'Jerry Haverkos'" <jhaverkos@columbus.rr.com>;
> "Ademola Osindero"
> >> > <osindero@lagos.sns.slb.com>; <ccielab@groupstudy.com>
> >> > Sent: Wednesday, May 29, 2002 3:34 PM
> >> > Subject: RE: OSPF - practice approach
> >> >
> >> >
> >> > > And what happens when you add more loopback interfaces
> and reload
> >> the
> >> > > router? What if you have virtual links? Nail it up!
> >> > >
> >> > > -----Original Message-----
> >> > > From: Jerry Haverkos [mailto:jhaverkos@columbus.rr.com]
> >> > > Sent: Wednesday, May 29, 2002 3:56 PM
> >> > > To: Ademola Osindero; ccielab@groupstudy.com
> >> > > Subject: RE: OSPF - practice approach
> >> > >
> >> > >
> >> > > A router-id will be picked for you, automatically.
> >> > >
> >> > > -----Original Message-----
> >> > > From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com]On Behalf
> >> Of
> >> > > Ademola Osindero
> >> > > Sent: Wednesday, May 29, 2002 12:02 PM
> >> > > To: ccielab@groupstudy.com
> >> > > Subject: OSPF - practice approach
> >> > >
> >> > >
> >> > > Hi Group,
> >> > >
> >> > > I working on approaches of answering ques in the lab.
> Do I really
> >> need
> >> to
> >> > > put a router id on my routers while configuring
> OSPF....am I allowed
> >> to
> >> > > just pick up an ip address and use it?
> >> > >
> >> > > Regards
> >> > >
> >> > > Osindero Ademola
> >> > > Schlumberger Network Solutions
> >> > > Tel: 234 1 261 0446 Ext 5427
> >> > > Fax 234 1 262 1034
> >> > > email:osindero@lagos.sns.slb.com
> >> > >
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