From: Simon Baxter (Simon.Baxter@xxxxxxxxxxxxxx)
Date: Fri Aug 25 2000 - 11:30:18 GMT-3
Here 'tis
All fair enough really!!
Moy Standards Track [Page 67]
RFC 2328 OSPF Version 2 April 1998
+----+ UnloopInd +--------+
|Down|<--------------|Loopback|
+----+ +--------+
|
|InterfaceUp
+-------+ | +--------------+
|Waiting|<-+-------------->|Point-to-point|
+-------+ +--------------+
|
WaitTimer|BackupSeen
|
|
| NeighborChange
+------+ +-+<---------------- +-------+
|Backup|<----------|?|----------------->|DROther|
+------+---------->+-+<-----+ +-------+
Neighbor | |
Change | |Neighbor
| |Change
| +--+
+---->|DR|
+--+
Figure 11: Interface State changes
In addition to the state transitions pictured,
Event InterfaceDown always forces Down State, and
Event LoopInd always forces Loopback State
Loopback
In this state, the router's interface to the network is
looped back. The interface may be looped back in hardware
or software. The interface will be unavailable for regular
data traffic. However, it may still be desirable to gain
information on the quality of this interface, either through
sending ICMP pings to the interface or through something
like a bit error test. For this reason, IP packets may
still be addressed to an interface in Loopback state. To
facilitate this, such interfaces are advertised in router-
LSAs as single host routes, whose destination is the IP
interface address.[4]
Thanks (all) again!
Simon
-----Original Message-----
From: Mike Loyer [mailto:mloyer@harbortech.com]
Sent: Saturday, August 26, 2000 12:30 AM
To: Geatti; Simon Baxter; CCIE Group Study (E-mail)
Subject: Re: 2nd attempt at a question!!
pulled this from the cisco tips Q&A section
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.
----- Original Message -----
From: "Geatti" <geatti@home.com>
To: "Simon Baxter" <Simon.Baxter@au.logical.com>; "CCIE Group Study
(E-mail)" <ccielab@groupstudy.com>
Sent: Friday, August 25, 2000 11:20 AM
Subject: RE: 2nd attempt at a question!!
> someone mentioned you could change the network type with certain ios
> versions 'ip ospf network....' Haven't tried it myself yet but look back
> a few days and you'll find the post.
>
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
> > Behalf Of Simon Baxter
> > Sent: Friday, August 25, 2000 9:51 AM
> > To: CCIE Group Study (E-mail)
> > Subject: 2nd attempt at a question!!
> >
> > I'm doing a test lab which has asked me if there's any way to
> > advertise routes to loopback interfaces as anything but /32 routes.
> >
> > I can't see any way around this :
> >
> > Link connected to: a Stub Network
> > (Link ID) Network/subnet number: 130.130.33.1
> > (Link Data) Network Mask: 255.255.255.255
> > Number of TOS metrics: 0
> > TOS 0 Metrics: 1
> >
> > R4#sh ip os int lo0
> > Loopback0 is up, line protocol is up
> > Internet Address 130.130.33.1/24, Area 0.0.0.0
> > Process ID 10, Router ID 130.130.33.1, Network Type LOOPBACK, Cost:
> > 1
> > Loopback interface is treated as a stub Host
> > R4#
> >
> >
> > No matter what I do, it always stays as "Loopback interface is treated
> > as a stub Host"
> >
> >
> > Is this a trick question???
> >
> > I'm losing WAY too much sleep over it..
> >
> >
> > Simon
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