From: Erick B. (erickbe@xxxxxxxxx)
Date: Fri Feb 23 2001 - 20:03:06 GMT-3
HSRP failover has no effect on OSPF talking correctly.
The routing protocols will handle the changes if a
router goes down. Instead of having 2 equal cost
routes to the LAN with HSRP on remote router when one
router or LAN interface goes down the remote router
will have 1 route if the frame is up. Routing will
handle this.
On the other hand, if a PVC goes down and both LAN
interfaces are up and a client has their default
gateway set to the physical IP interface of the router
with down PVC they should be redirected to the other
router. OSPF will learn about the remote networks from
the other router at this location and that router will
be the next hop until the PVC comes back up. Assuming
routing is working correctly.
You can use HSRP interface tracking feature to track
the WAN interface and adjust priority so the other
router becomes active when the WAN interface goes
down. This isn't going to help matters if you have no
control over what the clients use as a default
gateway. They will just be redirected out ethernet to
other router with route to remote site. You could turn
off ip redirects if you wanted their traffic just to
be dropped in this case.
If you could do a route-map match on if HSRP was in a
active state perhaps that would give you some
flexibility and control but thats not a feature at
moment nor do I know if it is planned.
I guess another solution would be to offer bountys on
people who don't use the HSRP IP address as their
default gateway :)
I hope this helps.
--- Dustin L LaMascus <lamascus@xs4all.nl> wrote:
> Guess it wasn't enough detail.. I am aware that OPSF
> is a routing protocol
> and HSRP is a redundancy protocol, as I hope anyone
> subscribed to this list
> is. ;-)
> If router 1 and router 2 are using HSRP both
> physical interfaces are still
> available (lets say 10.1.1.1 for R1 and 10.1.1.2 for
> R2, along with the
> "virtual" IP and MAC (lets say 10.1.1.3). The
> clients could set the default
> gateway to the "standby" router IP and still send
> traffic over a PVC (at
> least outgoing) that should be sleeping, not the
> desired scenario. I would
> like to limit traffic to ONLY the active router but
> I have no control over
> the host's configuration (default gateway). I would
> also like to ensure that
> OSPF continues to talk correctly in the event of a
> HSRP fail over with
> minimal convergence, if any.
>
> R1 and R2 both use OSPF on the LAN and redistribute
> into EIGRP for the WAN..
>
> Possible solutions I have thought of:
> Some how filter packets on the 10. interface of the
> standby router based on
> MAC ??
> Some how force OSPF to prefer the active router so
> that packets sent to the
> standby router are redirected to the active router
> Change the real IP addresses on R1 and R2 to another
> ip range and not add it
> to the OSPF or EIRGP process, this would make it so
> if a client were to be
> configured for the wrong default gateway the remote
> router would drop the
> packet due to not knowing the return route..
>
> Hope this is a little better defined, and btw I know
> that EIGRP is also a
> routing protocol ;-)
>
> Cheers,
>
> Dustin
>
>
> -----Original Message-----
> From: Erick B. [mailto:erickbe@yahoo.com]
> Sent: Friday, February 23, 2001 7:37 PM
> To: Andrew Short; Dustin L LaMascus
> Cc: CCIE
> Subject: Re: HSRP and OSPF???
>
> Some more notes. I've had to explain this to many
> folks. HSRP shares a virtual IP address between the
> HSRP devices in the same group on the same subnet.
> One
> is active and rest are in standby. The primary IP
> address and other IP services are up and running as
> normal still. HSRP does not put the whole interface
> in
> standby mode (this is what many of the folks I've
> talked to thought). If it's in standby then the
> virtual IP isn't active and thats it.
>
> Routing protocols do not announce routes using the
> HSRP IP address. HSRP is not a routing protocol.
>
> Andrew is right, HSRP/VRRP provide redundancy for
> hosts only.
>
> --- Andrew Short <ashort@wingedwheel.net> wrote:
> > Honestly,
> >
> > HSRP and OSPF should NEVER have anything to do
> with
> > each other. Operate
> > them on the same routers, sure, but you are
> talking
> > apples and oranges.
> >
> > OSPF is a routing protocol, let it choose it's
> > routes accordingly.
> >
> > HSRP is a high availability tool to serve hosts
> with
> > static routes
> > configured. And as far as I know, it doesn't work
> > on WAN interfaces (and
> > I don't know why it would, or why you'd want it
> > too).
> >
> > Think of HSRP as something that you aim at a HOST.
> >
> >
> > On Fri, 23 Feb 2001, Dustin L LaMascus wrote:
> >
> > > I would like to use HSRP on R1 and R2 for
> > redundancy to the WAN. I would also
> > > like to limit the OSPF network to using only the
> > HSRP (active) gateway.
> > > Hope this is enough detail..
> > >
> > >
> > > OSPF NETWORK
> > > | |
> > > | |
> > > | hsrp |
> > > R1-------R2
> > > | |
> > > | |
> > > FRAME CLOUD
> > > |
> > > |
> > > R3
> > >
> > >
> > > Dustin
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