From: Chuck Larrieu (chuck@xxxxxxxxxxxxx)
Date: Sat Feb 24 2001 - 02:52:46 GMT-3
You're right. The only effect of metric modification would be for other ospf
routers on the inside ( LAN side ) of the HSRP domain in question. Maybe
there are a bunch of Linux boxes and Win2K servers inside all running OSPF?
Chuck
-----Original Message-----
From: Erick B. [mailto:erickbe@yahoo.com]
Sent: Friday, February 23, 2001 9:18 PM
To: Chuck Larrieu; Dustin L LaMascus; Andrew Short
Cc: CCIE
Subject: RE: HSRP and OSPF???
Hey Chuck and Dustin,
Here's a solution to the clients default gateway
setting that you have no control over. You're going to
burn some IP address's doing this but...
Change the primary IP address's on the interfaces to
something not in use on the subnet. This will of
course effect connectivity and routing while changes
take place. Configure MHSRP and use the current
Physical interface IP address's as the standby
address's. Design it so one standby group is active on
one router and the other group is active on the other
(use priority, preempt, tracking). When one
interface/router fails then the router that is
functioning will be active for both standby IPs.
Interface tracking will allow the router to become
active for the standby group if the frame interface
goes down, etc.
This will allow you to load balance the traffic as
well between both routers when both are up. Set half
the users to one standby IP and the other half to the
other standby IP.
I don't understand how adjusting routes and metrics
would help in deciding a route between the two
routers. If HSRP fails on the LAN interfaces
connecting the routers then the hosts can't go through
that router and it's frame relay connection. They will
go through the one that is up unless both routers bite
the bullet. If routing works fine now... why make
changes to routing protocols?
Oh, I goofed with the comment about disabling
redirects earlier. Wasn't thinking clearly then.
Erick B.
--- Chuck Larrieu <chuck@cl.cncdsl.com> wrote:
>
> An interesting thread. I find it refreshing, in an
> odd sort of way, to see
> the inverse of the usual question about "how do I
> 'load balance' in this
> situation" I am curious, Dustin. What is the problem
> you are trying to
> solve?
>
> To influence the choice of route in terms of ospf,
> the options I can think
> of are 1) use the bandwidth command on the LAN
> interfaces of your HSRP/OSPF
> routers or 2) ( assuming that I correctly understand
> that the HSRP/OSPF
> routers are also EIGRP routers and that
> redistribution takes place on those
> routers ) use route maps or modify the redistribute
> commands to change the
> metrics of the EIGRP routes as they are
> redistributed into OSPF.
>
> Since ICMP redirects are disabled on HSRP
> interfaces, the problem you state
> about clients configured with the wrong gateways
> would not be overcome by
> that avenue. On the other hand, doesn't your DHCP
> configuration include a
> default gateway, which in this case would be the
> HSRP address?
>
> Chuck
>
> -----Original Message-----
> From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com] On Behalf Of
> Dustin L LaMascus
> Sent: Friday, February 23, 2001 1:23 PM
> To: erickbe@yahoo.com; Andrew Short
> Cc: CCIE
> Subject: RE: HSRP and OSPF???
>
> 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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