The only thing I can think of is with that setup you have, any traffic from
source .1.0 to destination 2.0 will be routed via the loopback and thus
dropped....Can't think of anything else....
Kenny
"Adrian Chew" <[EMAIL PROTECTED]> wrote in message
8lskht$quq$[EMAIL PROTECTED]">news:8lskht$quq$[EMAIL PROTECTED]...
> Brian,
>
> Thanks for the example - hitting the loopbacks on REMOTE routers is easy
to
> understand (as is loopback interfaces for BGP connections and OSPF Router
> IDs). However, I've seen traffic being routed to an IP address on the
same
> subnet as the router's loopback interface is on. Eg.
>
> E0 > R1 > Loop 0 > R1 > S0 > R2 > E0 > IP destination
>
> The actual destination IP address might be a subnet on some other remote
> router but the traffic is first directed to an IP address on the same
subnet
> as the router's own loopback address. I believe its done to avoid some
sort
> of traffic from hitting NAT on the way out, but having an access-list
> definition for NAT traffic should already take care of this.
>
> Take a look at the initial route-map configuration I gave - traffic from
E0
> bound for network 192.168.2.0/24 (not a destination on the router's own
> connected interfaces) is set for next-hop IP address of 192.168.255.2 (the
> router's loopback IP address is 192.168.255.1 with a /24 mask).
>
> Regards,
> Adrian
>
> "Brian" <[EMAIL PROTECTED]> wrote in message
> [EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> > On Fri, 28 Jul 2000, Adrian Chew wrote:
> >
> > > I've seen this in some configurations where traffic is sent via a
> route-map
> > > to an IP address that is on the same subnet as a router's loopback
> > > interface.
> > >
> > > Eg.
> > >
> > > interface ethernet 0
> > > ip address 192.168.1.1 255.255.255.0
> > > ip policy route-map abc
> > >
> > > interface loopback 0
> > > ip address 192.168.255.1 255.255.255.0
> > >
> > > access-list 100 permit ip 192.168.1.0 0.0.0.255 192.168.2.0 0.0.0.255
> > >
> > > route-map abc permit 10
> > > match ip address 100
> > > set ip next-hop 192.168.255.2
> > >
> > > Could anyone explain how having traffic routed via a loopback
interface
> > > might help in certain situations?
> >
> > load balacing for one.........
> >
> > For example:
> >
> > R1
> > ip cef
> >
> > int loopback 0
> > ip address 10.1.1.1 255.255.255.0
> >
> > int ethernet 0
> > ip address 192.168.2.1 255.255.255.0
> >
> > int serial 0
> > ip address 192.168.1.1 255.255.255.252
> > ip load-sharing per-packet
> >
> > int serial 1
> > ip address 192.168.1.5 255.255.255.252
> > ip load-sharing per-packet
> >
> > ip route 10.1.2.1 255.255.255.0 192.168.1.2
> > ip route 10.1.2.1 255.255.255.0 192.168.1.6
> > ip route 0.0.0.0 0.0.0.0 10.1.2.1
> >
> > R2
> > ip cef
> >
> > int loopback 0
> > ip address 10.1.2.1 255.255.255.0
> >
> > int serial 0
> > ip address 192.168.1.2 255.255.255.252
> > ip load-sharing per-packet
> >
> > int serial 1
> > ip address 192.168.1.6 255.255.255.252
> > ip load-sharing per-packet
> >
> > ip route 10.1.1.1 255.255.255.0 192.168.1.1
> > ip route 10.1.1.1 255.255.255.0 192.168.1.5
> > ip route 192.168.2.0 255.255.255.0 10.1.1.1
> >
> > You could save yourself some configuring and whatnot by using an IGP to
> > get the dual routes injected instead of declaring them statically here,
> > but I did static here to illustrate
> >
> > Brian
> >
> > >
> > > Thanks.
> > >
> > > Regards,
> > > Adrian
> > >
> > >
> > > ___________________________________
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> > >
> >
> > -----------------------------------------------
> > Brian Feeny, CCNA, CCDA [EMAIL PROTECTED]
> > Network Administrator
> > ShreveNet Inc. (ASN 11881)
> >
> > ___________________________________
> > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html
> > FAQ, list archives, and subscription info: http://www.groupstudy.com
> > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
> > ---
>
>
> ___________________________________
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