From: Brian Hescock (bhescock@xxxxxxxxx)
Date: Mon May 28 2001 - 23:35:07 GMT-3
I can't think of any way using a 0.0.0.0 wildcard bits would affect
redistribution, unless it's a bug. All the ospf network command does is turn o
n ospf on
the interface(s) covered by the network statement, that's all it does. It
has zero effect on the network mask being advertised and no effect on
redistribution. To everyone that said use a 0.0.0.0 mask (wildcard bits
actually), thumbs up, it's the preferred method unless you have a lot of interf
aces you need to turn
ospf on. Not just for lab use but for production networks as well. Less
chance for error and easier to troubleshoot.
Brian
On Mon, 28 May 2001, Jeff K. wrote:
> You are exactly right with all the shortcuts. I've never considered using
> aliases because I never use them day to day and know that it will wind up
> slowing me down since I type pretty fast. I know that I can calculate a
> wildcard mask easily and don't have a problem with it. Not my point,
> though... I was merely asking for an explanation as to why using the
> 0.0.0.0 area mask would affect route redistribution, which is a question
> that hasn't been answered. In my opinion, it makes good common sense as you
> put it to use the 0.0.0.0 mask except when using a wildcard mask that will
> allow you to group multiple interfaces into a single area (i.e., a single
> statement versus multiple statements). Since I always use logic when
> assigning my interface addressing schemes, the all 0 mask allows me to
> double check everything quickly and easily - I know what interface has what
> address and where it should be. Not that the wildcard mask makes that any
> more difficult - just my personal preference. If a bug or other
> 'undocumented feature' requires me to use the exact mask, I will be fine as
> well... Anyway, if you have an answer for my original question about why
> the area mask affects route redistribution (what I originally responded to),
> please respond. I am more curious than anything.
>
> Thanks,
>
> -Jeff
> ----- Original Message -----
> From: "Mike Hess" <mahess@home.com>
> To: <ccielab@groupstudy.com>
> Sent: Monday, May 28, 2001 7:06 PM
> Subject: RE: how anal is the lab grading
>
>
> > Why not just be smart and use a network statement and the right wildcard
> > mask for every interface that you are putting into OSPF? It seems common
> > sense to me not to try and get too pretty or cut too many corners and then
> > get end up with a problem with 15 minutes left just because you were too
> > lazy to be more specific in the first place.
> >
> > Some people advocate the use of too many shortcuts. I see a lot of people
> > advocating shortcuts such as this, using a whold slew of alias commands,
> > etc. Just learn the material and don't try to save seconds when it's the
> > minutes and hours that really matter.
> >
> > Back to my original point, if you cannot at this point calculate a simple
> > wildcard mask then you are going for the wrong certification. Perhaps it
> is
> > not the grading.... :-)
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> > Jeff K.
> > Sent: Monday, May 28, 2001 5:27 PM
> > To: Walter Chen; Peter Van Oene; ccielab@groupstudy.com
> > Subject: Re: how anal is the lab grading
> >
> >
> > You lost me on the second paragraph. Why would using the 0.0.0.0
> wild-card
> > mask for interface area identification affect redistribution? This mask
> > just allows you to use the interface's address. Obviously the subnet mask
> > of your interfaces will affect redistribution, but I don't see how the
> > 0.0.0.0 area mask will. You can definitely mess up your OSPF topology by
> > using the wrong mask (i.e., interfaces in the wrong area, interfaces added
> > to OSPF that weren't supposed to be). Let me know what your thoughts are
> on
> > this. Maybe I am forgetting something or am just misunderstanding
> > something.
> >
> > Thanks,
> >
> > -Jeff
> > ----- Original Message -----
> > From: "Walter Chen" <wchen@iloka.com>
> > To: "Peter Van Oene" <pvo@usermail.com>; <ccielab@groupstudy.com>
> > Sent: Monday, May 28, 2001 3:04 PM
> > Subject: Re: how anal is the lab grading
> >
> >
> > > IMHO, you can use 0.0.0.255 mask if you have other 1.1.1.x/29 networks
> > onthe
> > > same router and they also belong to the same OSPF area. However, if
> these
> > > networks should not be in OSPF or in the same area, you definitely
> should
> > > not use 0.0.0.255 mask. The absolutely sure and correct way is to use
> > > 0.0.0.7 mask for 1.1.1.0/29 network.
> > >
> > > You can use 0.0.0.0 mask in cases if you do not need to redistribute
> > > 1.1.1.0/29 into other routing protocols on this same router. However,
> if,
> > > say, your 192.168.1.0/24 belongs to EIGRP and you want to reistribute
> > > between OSPF and EIGRP, the 1.1.1.0/29 network will NOT be passed into
> > EIGRP
> > > if you have used 0.0.0.0 mask.
> > >
> > > Walter
> > >
> > > ----- Original Message -----
> > > From: Peter Van Oene <pvo@usermail.com>
> > > To: <ccielab@groupstudy.com>
> > > Sent: Monday, May 28, 2001 9:35 AM
> > > Subject: Re: how anal is the lab grading
> > >
> > >
> > > > Personally, I'd not use 0.0.0.255 in any case, lab or otherwise. The
> > full
> > > 0's mask is the safe and accurate way to add interfaces to the OSPF
> > process
> > > and unless you need to add 20 odd interfaces, I'd suggest you use it.
> As
> > > far as the lab goes, I can attest that lab grading is fair. You
> shouldn't
> > > worry about trivial semantics. If your prepared, you'll likely have a
> > good
> > > idea when you are using an illegal shortcut.
> > > >
> > > > Pete
> > > >
> > > >
> > > > *********** REPLY SEPARATOR ***********
> > > >
> > > > On 5/28/2001 at 7:48 AM Don Dettmore wrote:
> > > >
> > > > >Question - How nit-picky are the graders of the lab? F0r example,
> > > > >something
> > > > >occurred to me when I was working in the lab:
> > > > >
> > > > >192.168.1.0 /24 ------ R1 ----- 1.1.1.0 /29
> > > > >
> > > > >When configuring R1 for OSPF, would the following be acceptable:
> > > > >
> > > > >network 1.1.1.0 0.0.0.255 area 0.0.0.0
> > > > >
> > > > >Or would that be considered wrong because of the 'wrong' (or I should
> > > say -
> > > > >not specific enough) wildcard mask.
> > > > >
> > > > >Just wondering how anal I must train myself to be.
> > > > >
> > > > >Don Dettmore
> > > > >**Please read:http://www.groupstudy.com/list/posting.html
> > > > **Please read:http://www.groupstudy.com/list/posting.html
> > > **Please read:http://www.groupstudy.com/list/posting.html
> > **Please read:http://www.groupstudy.com/list/posting.html
> > **Please read:http://www.groupstudy.com/list/posting.html
> **Please read:http://www.groupstudy.com/list/posting.html
**Please read:http://www.groupstudy.com/list/posting.html
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