Re: distance 0.0.0.0 255.255.255.255 [word] - standard ip

Arron:

Thanks for response. I am about to login to rack and look at this in more
detail but I did want to entertain your questions first.

How would ospf *set AD on an eigrp route? *Eigrp is being redistributed
into OSPF. To the OSPF neighbors, it is an OSPF OE2 route.

Isn't AD for setting/adjusting AD on intra-igp prefixes? AD is 2nd decision
made by a router to populate RIB. First decision is prefix legnth. 2
routes can exist in a routing table to the same destination but the on with
longer prefix length wins. A striking difference between AD compared to
prefix legnth is that with decisions made based on AD will stop an
advertisement from making the routing table.

Correct me if I'm wrong but I don't think IGP A can set AD on IGPB. That is
right but to get full reachibilty, redistribution might be needed. When
that is the case that IGP A's routes will be IGP B's when advertising to
neighbors.

Anyways. All good food for thought. I am logging into routers now. Will
have an update in the AM.

Cheers,

Marc

On Wed, Jan 25, 2012 at 5:04 PM, Aaron <aaron1_at_gvtc.com> wrote:

> I think someone already pointed out that AD isn't advertised to neighbors
> but is only locally significant. So that clears up why R1 doesn't see or
> wouldn't possibly see an AD 171 put on R4 and then sent to R1, won't
> happen.
>
> And then it seems that there is the question about not seeing hits on the
> acl read into ospf via distance command....it seems that this might be
> because the route prefixes (specifically the one from SW3 (lo7 -
> 135.15.107.0) that shows up at R4, shows up on R4 via EIGRP. How would
> ospf
> set AD on an eigrp route? Isn't AD for setting/adjusting AD on intra-igp
> prefixes? Correct me if I'm wrong but I don't think IGP A can set AD on
> IGP
> B. In other words, I don't think OSPF can set AD on eigrp learned routes.
> I think you would have to go into eigrp router process and set AD to 171
> there on R4 if that's what you wanted to do.
>
> Aaron
>
> ************ sent in previous email *****************************
>
> lo7-SW3->EIGRP->R4->OSPF->R1
>
> lo7 shows up in r4 table as eigrp external:
>
> D EX 135.15.107.0 [170/261120] via 135.15.20.7, 04:47:15,
> FastEthernet0/0
>
> Here is relevant config on R4:
>
> router ospf 1
> log-adjacency-changes
> area 10 virtual-link 135.15.101.1
> redistribute connected subnets route-map connected->ospf
> redistribute eigrp 30 subnets route-map eigrp->ospf
> network 135.15.10.4 0.0.0.0 area 0
> network 135.15.14.4 0.0.0.0 area 10
> network 135 15.34.4 0.0.0.0 area 10
> distance 171 0.0.0.0 255.255.255.255 ospf-distance
>
> R4#sh ip access-lists ospf-distance
> Standard IP access list ospf-distance
> 10 permit 135.15.107.0
> 20 permit 135.15.110.0
> 30 permit 135.15.120.0
>
> I am not seeing any hits on ACL nor am these routes on R1 with a distance
> of
> 171:
>
> O E2 135.15.107.0 [110/20] via 135.15.14.4, 00:00:17, Serial0/0/0.14
>
> *****************************************************************
>
>
> -----Original Message-----
> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> marc
> edwards
> Sent: Wednesday, January 25, 2012 2:43 PM
> To: Christian Hunter
> Cc: Nick E; Cisco certification
> Subject: Re: distance 0.0.0.0 255.255.255.255 [word] - standard ip access
> list
>
> sorry i keep confusing AD with metric. I still don't see AD change. In any
> event I will be working through this and most likely post a follow up.
> thanks for help so far.
>
> On Wed, Jan 25, 2012 at 8:40 AM, marc edwards <renorider_at_gmail.com> wrote:
>
> > Thanks Christian:
> >
> > I am working through a redistribution-heavy Cisco 360 lab. Commands came
> > from the CLI mentor (answer key). I understand that this is
> > locally significant. If that is the case, then I am not understanding why
> > the configuration is used as this subnet was never OSPF owned.
> >
> > I did test moving the AD to 10 on OSPF. It didn't change metric on
> routing
> > table...
> >
> > Marc
> >
> > On Wed, Jan 25, 2012 at 7:38 AM, Christian Hunter
> <stasis416_at_gmail.com>wrote:
> >
> >> I'm not sure I'm understanding what your trying to achieve. However,
> your
> >> stating that your not seeing routes on R1 with a distance of 171 and the
> >> relevant config you post is for R4 where your setting distance to 171
> via
> >> the standard named ACL.
> >>
> >> Remember distance is locally significant. If you change the distance on
> a
> >> router it impacts how that router determines feasibility of routing
> >> protocols, AD doesn't get passed on the routing domain. So if you want
> to
> >> see R1 with routes of 171 AD, you need to modify the distance there.
> Your
> >> solution of how your applying distance looks fine. It just needs to be a
> >> standard ACL.
> >>
> >> Hope that helps.
> >> Christian Hunter
> >>
> >>
> >>
> >> On Wed, Jan 25, 2012 at 9:37 AM, marc edwards <renorider_at_gmail.com
> >wrote:
> >>
> >>> Btw. Still no change to AD.
> >>>
> >>> On Wednesday, January 25, 2012, marc edwards <renorider_at_gmail.com>
> >>> wrote:
> >>> > Sorry nick. I meant AD.... Thanks for clarification
> >>> >
> >>> > On Wednesday, January 25, 2012, Nick E <ccienovice_at_gmail.com> wrote:
> >>> >> Hi Marc,
> >>> >>
> >>> >> distance command will change the AD on the router and not the
> metric.
> >>> If
> >>> you want change the metric use the below command:-
> >>> >>
> >>> >> redistribute eigrp 30 metric 171 subnets
> >>> >>
> >>> >> Cheers,
> >>> >> Nick
> >>> >>
> >>> >> On Wed, Jan 25, 2012 at 11:00 AM, marc edwards <renorider_at_gmail.com
> >
> >>> wrote:
> >>> >>>
> I have :
> >>> >>>
> lo7-SW3->EIGRP->R4->OSPF->R1
> >>> >>>
> lo7 shows up in r4 table as eigrp external:
> >>> >>>
> D EX 135.15.107.0 [170/261120] via 135.15.20.7, 04:47:15,
> >>> FastEthernet0/0
> >>> >>>
> I am redistributing this into ospf 1 and sending along to r1
> >>> >>>
> Type-5 AS External Link States
> >>> >>>
> Link ID ADV Router Age Seq# Checksum Tag
> 135.15.107.0 135.15.104.1 1314 0x80000002 0x009409 0
> >>> >>>
> Furthermore this is advertised with AD of 171 not to overtake routes
> >>> that
> could potentially show up on neighbor with a 'distance 171 0.0.0.0
> 255.255.255.255 ospf-distance'
> >>> >>>
> R4#sh ip access-lists ospf-distance
> Standard IP access list ospf-distance
> 10 permit 135.15.107.0
> 20 permit 135.15.110.0
> 30 permit 135.15.120.0
> >>> >>>
> I am not seeing any hits on ACL nor am these routes on R1 with a
> >>> distance
> of 171:
> >>> >>>
> O E2 135.15.107.0 [110/20] via 135.15.14.4, 00:00:17,
> >>> Serial0/0/0.14
> >>> >>>
> >>> >>>
> Here is relavant config on R4:
> >>> >>>
> router ospf 1
> log-adjacency-changes
> area 10 virtual-link 135.15.101.1
> redistribute connected subnets route-map connected->ospf
> redistribute eigrp 30 subnets route-map eigrp->ospf
> network 135.15.10.4 0.0.0.0 area 0
> network 135.15.14.4 0.0.0.0 area 10
> network 135.15.34.4 0.0.0.0 area 10
> distance 171 0.0.0.0 255.255.255.255 ospf-distance
> >>> >>>
> ip access-list standard ospf-distance
> permit 135.15.107.0
> permit 135.15.110.0
> permit 135.15.120.0
> >>> >>>
> >>> >>>
> I thought this would redistribute eigrp learned route with metric of
> >>> 171 to
> neighbors. This isn't a big problem on R1 but it causes a recursive
> >>> routing
> problem on neighbor R5.... Am I not understanding how this command
> >>> works?
> >>> >>>
> >>> >>>
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Received on Wed Jan 25 2012 - 20:40:53 ART