From: Ben (bmunyao@gmail.com)
Date: Mon Jun 18 2007 - 15:34:13 ART
Thanks Tarun
You are right, "distribute-list acl ..." only accepts standard ACLs (hadn't
checked it out).
Except for the link you sent, I could not find "distribute-list prefix ..."
in DocCD. Perhaps I'm going blind from spending the last 14hrs hunched in
front of my laptop (lab, reading etc) :)
Ben
On 6/18/07, Tarun Pahuja <pahujat@gmail.com> wrote:
>
> Ben,
> My comments were based on the following document and I was
> referring to standard ACLs.
>
> http://www.cisco.com/warp/public/103/eigrpfaq.shtml
>
> "The use of ACL and distribute-list under EIGRP does not work in this
> case. This is because ACLs do not check the mask, they just check the
> network portion. Since the network portion is the same, when you allow
> 172.16.1.0/24, you also allow 172.16.1.0/28."
>
> I usually use Prefix-list for route filtering as it gives me more control.
> I have seen cases where extended ACLs are used to match subnet mask, but the
> logic is slightly different as you suggested. Destination portion becomes
> the subnet mask portion. You will find prefix list must easier to implement
> specially when dealing with VLSM addresses.
>
> HTH,
> Tarun
>
>
> On 6/18/07, Ben <bmunyao@gmail.com> wrote:
> >
> > Tarun
> >
> > "remember ACLs will not match subnet mask."
> >
> >
> > Correct me if I'm off track but I was under the impression an ACL can
> > also match a subnet mask as follow:
> >
> > access-list 100 permit ip host 150.4.5.0 host 255.255.255.0
> >
> > I haven't tested it in a lab yet, so I'm still unsure if it works. I'd
> > sure appreciate any input on this ACL usage.
> >
> > Ben
> >
> >
> >
> >
> > On 6/18/07, Tarun Pahuja < pahujat@gmail.com> wrote:
> >
> > > Yan,
> > > You are right about the use to route-map for advanced
> > > filtering. I
> > > am not aware of any limitations of distributing routes in and out of
> > > eigrp
> > > in terms of routing protocols. Remember, to specify the metric when
> > > redistributing in eigrp as their is no default metric, also use
> > > prefix-list
> > > in place of ACLs for better control, remember ACLs will not match
> > > subnet
> > > mask.
> > >
> > > For your second question, It is more useful in many cases to configure
> > > the
> > > route map that includes matching the route type based on the source
> > > protocol
> > > and AS using the distribute-list command for EIGRP.
> > >
> > > In the following example, the source protocol is specified as Border
> > > Gateway
> > > Protocol (BGP) and the AS number is 2, which permits external EIGRP
> > > routes
> > > of BGP:
> > >
> > > match source-protocol bgp 2
> > >
> > > HTH,
> > > Tarun
> > >
> > >
> > > On 6/17/07, Filyurin, Yan <yan.filyurin@eds.com> wrote:
> > > >
> > > > Hello Groupstudy. Recently I've reading up EIGRP support for route
> > > maps
> > > > and the way they explain it is that it almost works like a
> > > distribute
> > > > list where you can do advanced matching on incoming routes. However
> > > > according to some playing around and documentation, use of route-map
> > > in
> > > > a distribute list is only supported with OSPF. So here I was
> > > reading
> > > > this URL:
> > > >
> > > >
> > > http://www.cisco.com/en/US/products/sw/iosswrel/ps5207/products_feature_
> > > > guide09186a0080220721.html
> > > >
> > > > And the part that confused me the most was this
> > > >
> > > > "
> > > > The EIGRP Route Map Support feature enables Enhanced Interior
> > > Gateway
> > > > Routing Protocol (EIGRP) to interoperate with other protocols by
> > > > filtering inbound and outbound traffic based on complex route map
> > > > options.
> > > > "
> > > >
> > > > Am I just confused by the description and that URL gives nothing
> > > more
> > > > than ability to redistribute the routes better by matching on some
> > > of
> > > > the parameters of other protocols, or is actual route filtering
> > > > involved. And in case of the second, how would it even know which
> > > > source protocol it originally came from. Sounds very logical, so
> > > just
> > > > wanted to do a sanity check.
> > > >
> > > > Thank you
> > > >
> > > > Yan
> > > >
> > > >
> > > _______________________________________________________________________
> > > > Subscription information may be found at:
> > > > http://www.groupstudy.com/list/CCIELab.html
> > >
> > >
> > > _______________________________________________________________________
> > > Subscription information may be found at:
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> > >
> >
> >
> >
> > --
> > Benedict Munyao
> > Dimension Data
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