From: Krake, Kris (KKrake@xxxxxxxxxxxx)
Date: Wed Nov 07 2001 - 19:33:41 GMT-3
Any chance the network is configured on a loopback? Unless you've got 11.3
or later IOS OSPF will advertise only the host route and not the network on
a loopback. Didn't see a config so I'm not sure that isn't the case.
Reason that I mention that is because redistributing is one way to fix
that....
>From http://www.cisco.com/warp/public/104/9.html#QB
Q: Why are loopbacks advertised as /32 host routes in OSPF?
A: Loopbacks are considered host routes in OSPF, and they're advertised as
/32. For more information, see section 9.1 of RFC 2328. In Cisco IOS .
version 11.3T and 12.0, if the ip ospf network point-to-point command is
configured under loopbacks, then OSPF advertises the loopback subnet as the
actual subnet configured on loopbacks.
Kris
-----Original Message-----
From: Jason Gardiner [mailto:gardiner@sprint.net]
Sent: Wednesday, November 07, 2001 5:04 PM
To: SFeldberg@edeltacom.com
Cc: CCIE Groupstudy; Courtney Foster; Larson, Chris (Contractor); lgao;
nobody@groupstudy.com; 'Ben-Shalom, Omer'; Dennis #6
Subject: Re: CCBootCamp 5 OSPF over frame question
I'll try it at home later and post if I have the same issues. I'm just
trying way to much weird stiff on these routers - Virtual Token rings
interfaces, DLSW and Back-to-back AUX dialer connections - to shoot the
problem. I did notice that you are still using a /8 inverse mask on the
R4. Change that to a host mask and see if it still works right :)
SFeldberg@edeltacom.com wrote:
>
> Post your configs- I'll bet you were had an OSPF network type of
> point-to-multipoint. I built the scenario using point-to-point links and
> it did what it was supposed to. See below:
>
> r2#sh run
> !
> interface Ethernet0
> ip address 20.1.1.1 255.255.255.0
> no ip directed-broadcast
> !
> interface Serial1
> ip address 10.1.1.2 255.255.255.0
> no ip directed-broadcast
> clockrate 64000
> !
> router ospf 1
> network 10.1.1.2 0.0.0.0 area 0
> network 20.1.1.1 0.0.0.0 area 1
>
> r2#sh ip route
>
> 20.0.0.0/24 is subnetted, 1 subnets
> C 20.1.1.0 is directly connected, Ethernet0
> 10.0.0.0/24 is subnetted, 2 subnets
> O 10.2.2.0 [110/74] via 10.1.1.4, 00:04:08, Serial1
> C 10.1.1.0 is directly connected, Serial1
>
> r2#sh ip ospf
> Routing Process "ospf 1" with ID 10.1.1.2
> Supports only single TOS(TOS0) routes
> It is an area border router
> SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
> Minimum LSA interval 5 secs. Minimum LSA arrival 1 secs
> Number of external LSA 0. Checksum Sum 0x0
> Number of DCbitless external LSA 0
> Number of DoNotAge external LSA 0
> Number of areas in this router is 2. 2 normal 0 stub 0 nssa
> Area BACKBONE(0)
> Number of interfaces in this area is 1
> Area has no authentication
> SPF algorithm executed 18 times
> Area ranges are
> Number of LSA 5. Checksum Sum 0x219AA
> Number of DCbitless LSA 0
> Number of indication LSA 0
> Number of DoNotAge LSA 0
> Area 1
> Number of interfaces in this area is 1
> Area has no authentication
> SPF algorithm executed 6 times
> Area ranges are
> Number of LSA 3. Checksum Sum 0x1634B
> Number of DCbitless LSA 0
> Number of indication LSA 0
> Number of DoNotAge LSA 0
>
> r2#sh ip ospf int s1
> Serial1 is up, line protocol is up
> Internet Address 10.1.1.2/24, Area 0
> Process ID 1, Router ID 20.1.1.1, Network Type POINT_TO_POINT, Cost: 64
> Transmit Delay is 1 sec, State POINT_TO_POINT,
> Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
> Hello due in 00:00:01
> Neighbor Count is 1, Adjacent neighbor count is 1
> Adjacent with neighbor 10.2.2.2
> Suppress hello for 0 neighbor(s)
>
> r4#sh run
> !
> interface Ethernet0
> ip address 10.2.2.2 255.255.255.0
> no ip directed-broadcast
> !
> interface Serial1
> ip address 10.1.1.4 255.255.255.0
> no ip directed-broadcast
> !
> router ospf 1
> network 10.0.0.0 0.255.255.255 area 0
>
> r4#sh ip route
>
> 20.0.0.0/24 is subnetted, 1 subnets
> O IA 20.1.1.0 [110/74] via 10.1.1.2, 00:04:19, Serial1
> 10.0.0.0/24 is subnetted, 2 subnets
> C 10.2.2.0 is directly connected, Ethernet0
> C 10.1.1.0 is directly connected, Serial1
>
> r4#sh ip ospf
> Routing Process "ospf 1" with ID 10.1.1.4
> Supports only single TOS(TOS0) routes
> Supports opaque LSA
> SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
> Minimum LSA interval 5 secs. Minimum LSA arrival 1 secs
> Number of external LSA 0. Checksum Sum 0x0
> Number of opaque AS LSA 0. Checksum Sum 0x0
> Number of DCbitless external and opaque AS LSA 0
> Number of DoNotAge external and opaque AS LSA 0
> Number of areas in this router is 1. 1 normal 0 stub 0 nssa
> External flood list length 0
> Area BACKBONE(0)
> Number of interfaces in this area is 2
> Area has no authentication
> SPF algorithm executed 18 times
> Area ranges are
> Number of LSA 7. Checksum Sum 0x21240
> Number of opaque link LSA 0. Checksum Sum 0x0
> Number of DCbitless LSA 0
> Number of indication LSA 0
> Number of DoNotAge LSA 0
> Flood list length 0
>
> r4#sh ip ospf int s1
> Serial1 is up, line protocol is up
> Internet Address 10.1.1.4/24, Area 0
> Process ID 1, Router ID 10.2.2.2, Network Type POINT_TO_POINT, Cost: 64
> Transmit Delay is 1 sec, State POINT_TO_POINT,
> Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
> Hello due in 00:00:04
> Index 2/2, flood queue length 0
> Next 0x0(0)/0x0(0)
> Last flood scan length is 1, maximum is 1
> Last flood scan time is 0 msec, maximum is 0 msec
> Neighbor Count is 1, Adjacent neighbor count is 1
> Adjacent with neighbor 20.1.1.1
> Suppress hello for 0 neighbor(s)
>
> Steve
>
>
> Jason
> Gardiner To: "Larson, Chris
(Contractor)"
> <gardiner@spr <Chris.Larson@ed.gov>
> int.net> cc: "'Ben-Shalom, Omer'"
> Sent by: <omer.ben-shalom@intel.com>, lgao
<lgao@cisco.com>,
> nobody@groups Courtney Foster
<cfoster@cnr.edu>, Dennis #6
> tudy.com <vacant@home.com>, CCIE
Groupstudy
> <ccielab@groupstudy.com>
> Subject: Re: CCBootCamp 5
OSPF over frame
> 11/07/2001 question
> 04:35 PM
> Please
> respond to
> Jason
> Gardiner
>
>
>
> OK, I tried to put this to the test. When I configured networks with a
> host mask, they show up in the remote routing table as /32s. In order
> for the whole network to show up, I had to redist connected subnets.
> There's to many variables in this setup. I prefer using the network
> statement with the mask of the interface to be injected. It just works
> better for me.
>
> "Larson, Chris (Contractor)" wrote:
> >
> > Good point. I never really thought about it that way, but your right of
> > course. The network statement simply identifies (in the case of OSPF)
> which
> > interfaces to advertise out of and therefore a host route would work.
> >
> > Thinking about it like that, I cannot really think of any instances
where
> > you would not want to , or could not simply use a host route. Would
> everyone
> > agree with that????
> >
> > Are there instances where you could not?
> >
> > -----Original Message-----
> > From: Ben-Shalom, Omer [mailto:omer.ben-shalom@intel.com]
> > Sent: Wednesday, November 07, 2001 3:00 PM
> > To: lgao; Courtney Foster
> > Cc: Dennis #6; CCIE Groupstudy
> > Subject: RE: CCBootCamp 5 OSPF over frame question
> >
> > The OSPF network statement really has nothing to do with networks it is
> an
> > access list (and that is why it uses the mask the way it does) to filter
> the
> > interfaces to take part in OSPF, you COULD use the right network mask
for
> > the interfaces or not, that is really a style issue.
> > A while back I asked the same thing stating that I personally prefer the
> > network mask to a host mask but later was convinced by a number of good
> > people that unless you have a big router with many interfaces using the
> host
> > mask is cleaner and less prone to mistakes and surprises so I am now
> using a
> > host mask.
> >
> > Again - both will work and this is really a style issue nothing more.
> >
> > Omer.
> >
> > -----Original Message-----
> > From: lgao [mailto:lgao@cisco.com]
> > Sent: Wed, November 07, 2001 7:57 PM
> > To: Courtney Foster
> > Cc: Dennis #6; CCIE Groupstudy
> > Subject: Re: CCBootCamp 5 OSPF over frame question
> >
> > I don't think it is the best practice to advertise a host mask, it looks
> > like a lazy thing that dont' want to figure out what the true mask is.
> >
> > Courtney Foster wrote:
> >
> > > It is a host specific mask....because you don't have broadcast...you
> are
> > > telling OSPF that this host is Area 10...At least that's what I think
> > >
> > > -----Original Message-----
> > > From: Dennis #6 [mailto:vacant@home.com]
> > > Sent: Wednesday, November 07, 2001 12:04 PM
> > > To: CCIE Groupstudy
> > > Subject: CCBootCamp 5 OSPF over frame question
> > >
> > > I noticed on the CCBootCamp lab 5 solution that the wildcard mask on
> > > each router for the point-to-multipoint frame connections is 0.0.0.0
> > > (see below). Is there a good reason for using this mask as opposed to
> > > 0.0.0.255 (it's a /24 subnet)? When is it best to use 0.0.0.0 versus
> > > 0.0.0.255. I thought it was normal to use the inverse mask that
> > > corresponds to the subnet mask on that interface. What am I missing?
> > >
> > > router ospf 1
> > > redistribute igrp 1 metric 20 metric-type 1 subnets
> > > network 172.168.100.5 0.0.0.0 area 10 !point to multipoint frame
> > > connection network 137.20.20.0 0.0.0.255 area 0 area 10 virtual-link
> > > 172.168.30.97 area 10 virtual-link 172.168.100.6
> > >
> > > Thanks,
> > >
> > > Dennis #6
> --
> Thanks,
>
> Jason Gardiner
> Supervisor, Engineering Services
> Sprint <Insert Division Name>
>
> "You can swim all day in the Sea of Knowledge and
> still come out completely dry. Most people do."
>
> - Norton Juster
-- Thanks,Jason Gardiner Supervisor, Engineering Services Sprint <Insert Division Name>
"You can swim all day in the Sea of Knowledge and still come out completely dry. Most people do."
- Norton Juster
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