From: Anthony Pace (anthonypace@xxxxxxxxxxx)
Date: Fri Jul 19 2002 - 20:29:51 GMT-3
Why are we assuming that a route to a next hop shows up in the IP
routing table and a route to an interface does not? They both show up
unless there is another identical route with a lower AD. How does the
"interface vs. layer3 address" play into wheather or not the route is
"hidden" or wheather it jumps into the IP routeing table?
Anthony Pace
On Mon, 15 Jul 2002 19:46:52 -0700, "Brian Dennis" <brian@5g.net> said:
> Mamoor,
> The idea was to illustrate how a static route worked when pointed to an
> interface as opposed to an IP address. I through in the dialer map part
> just to point out that the issue isn't technically with the static
> route
> but is a layer 3 to layer 2 mapping issue.
>
> Also I think that a proctor would call that a default route in the
> actual CCIE lab ;-)
>
> Brian Dennis, CCIE #2210 (R&S/ISP Dial)
>
> -----Original Message-----
> From: Ahmed Mamoor Amimi [mailto:mamoor@ieee.org]
> Sent: Monday, July 15, 2002 8:20 PM
> To: Brian Dennis; 'Yakout Esmat'; 'Groupstudy'
> Subject: Re: Default route over ISDN
>
> Yes that also worked for me .... but this is actually not a default
> route.
> this is some sort of static route create with the dialer-map and that
> default route will only work for that ip address that is mapped not for
> others.
> The way around in this will be the dialer string.
>
>
> -Mamoor
>
>
>
> ----- Original Message -----
> From: Brian Dennis <brian@5g.net>
> To: 'Ahmed Mamoor Amimi' <mamoor@ieee.org>; 'Yakout Esmat'
> <yesmat@iprimus.com.au>; 'Groupstudy' <ccielab@groupstudy.com>
> Sent: Tuesday, July 16, 2002 6:39 AM
> Subject: RE: Default route over ISDN
>
>
> > Mamoor,
> > Did you actually try this in a lab and verify that it didn't work?
> Works
> > in my lab. See below.
> >
> > Brian Dennis, CCIE #2210 (R&S/ISP Dial)
> >
> >
> > <R2>
> > interface BRI0
> > ip address 192.168.1.2 255.255.255.0
> > dialer map ip 10.1.1.1 2029
> > dialer map ip 192.168.1.6 broadcast 2029
> > dialer-group 1
> > isdn switch-type basic-ni
> > isdn spid1 2028
> > !
> > ip route 0.0.0.0 0.0.0.0 BRI0
> > !
> > dialer-list 1 protocol ip permit
> > !
> > </R2>
> >
> > <R6>
> > interface Loopback0
> > ip address 10.1.1.1 255.255.255.0
> > !
> > interface BRI0
> > ip address 192.168.1.6 255.255.255.0
> > dialer map ip 192.168.1.2 broadcast 2028
> > dialer-group 1
> > isdn switch-type basic-ni
> > isdn spid1 2029
> > !
> > dialer-list 1 protocol ip permit
> > </6>
> >
> > R2#ping 10.1.1.1
> >
> > Type escape sequence to abort.
> > Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:
> > !!!!!
> > Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/40
> ms
> > R2#
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> Of
> > Ahmed Mamoor Amimi
> > Sent: Monday, July 15, 2002 6:47 PM
> > To: Yakout Esmat; Brian Dennis; 'Groupstudy'
> > Subject: Re: Default route over ISDN
> >
> > it will not work either that way by putting the map in local. u surely
> > need
> > to use the dialer profile or use dialer string if pointing to the bri
> > interface
> >
> > -Mamoor
> >
> >
> > ----- Original Message -----
> > From: Yakout Esmat <yesmat@iprimus.com.au>
> > To: Brian Dennis <brian@5g.net>; 'Groupstudy' <ccielab@groupstudy.com>
> > Sent: Tuesday, July 16, 2002 5:10 AM
> > Subject: RE: Default route over ISDN
> >
> >
> > > Brian,
> > >
> > > I see the logic behind it, and am sure that if I put another mapping
> > > statement in there it should work, I will try that and post the
> > results.
> > >
> > > Or maybe if I use dialer string instead of dialer map.
> > >
> > > CHeers
> > > yakout
> > >
> > > -----Original Message-----
> > > From: Brian Dennis [mailto:brian@5g.net]
> > > Sent: Tuesday, July 16, 2002 5:51 AM
> > > To: 'Yakout esmat'; 'Groupstudy'
> > > Subject: RE: Default route over ISDN
> > >
> > >
> > > Think about it like this. If you tell the router using the "ip route
> > > 0.0.0.0 0.0.0.0 bri0" command that all networks that aren't
> explicitly
> > > in the routing table are directly connected to BRI0, why would you
> > > expect the router to send them to 192.168.1.1?
> > >
> > > With the default route pointing to the interface the router wants to
> > > send the packet directly to address 10.1.1.1 (the packet's
> > destination).
> > > Since you don't have a dialer map to the 10.1.1.1 address you are
> > > getting the encapsulation failed messages. When you point the
> default
> > to
> > > the 192.168.1.1 address the router uses the 192.168.1.1 dialer map
> to
> > > get to it. As a side note you could also put a dialer map to the
> > > 10.1.1.1 address and you would have been able to ping it with the
> > > default route pointing to the BRI0 interface.
> > >
> > > What I recommend you doing is getting a "sniffer" and doing this on
> an
> > > Ethernet network. Try pointing a static route to an interface and
> try
> > > pointing a static route to an IP address of another router. You'll
> be
> > > able to see the difference in who the router ARPs for.
> > >
> > > Brian Dennis, CCIE #2210 (R&S/ISP Dial)
> > >
> > >
> > > -----Original Message-----
> > > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> > Of
> > > Yakout esmat
> > > Sent: Monday, July 15, 2002 7:01 AM
> > > To: Groupstudy
> > > Subject: Default route over ISDN
> > >
> > > Any body aware of this problem..
> > >
> > > Scenario:
> > >
> > > 10.1.1.1/24--[R1]------(192.168.1.0/24)-----[R2]----
> > > ISDN
> > >
> > > 1) R2 is configured with a static default route
> > >
> > > Problem:
> > >
> > > 1) If the default static route on R2 is pointing to BRI0 interface
> "ip
> > > route
> > > 0.0.0.0 0.0.0.0 bri0", R2 can't ping 10.1.1.1 on R1. Getting
> > > "encapsulation
> > > failed" error when debuging ip packets, and R2 can't initiate a
> dial.
> > >
> > > 2) If I cahnge the default to point to next hop instead "ip route
> > > 0.0.0.0
> > > 0.0.0.0 192.168.1.1", every thing is sweet
> > >
> > > IOS 12.1, legacy ISDN with single dialer map statement is used, IP
> > > classless
> > > is on...
> > >
> > > I must be missing some thing.
> > >
> > > Thanks
> > >
> > > Yakout
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