From: Sanjay Bhakta (sbhakta@xxxxxxxxxxx)
Date: Tue Aug 29 2000 - 20:06:30 GMT-3
My understanding is that interesting traffic will bring the link up, however
other traffic will keep the link up. In you situation if you don't won't
EIGRP to bring the link up, and therefore you have made it uninteresting.
Once the BRI is up you don't wont the EIGRP to keep it up, here you would
use "ip access-group" to prevent this.
Dialer watch allows you to track a route in your route table. As soon as
the route that you are watching disapears from you routing table, the BRI
will be brought up. This allows you to track a main interface without using
a backup command.
********
Sanjay Bhakta (RTP 9/24)
----- Original Message -----
From: "Brian Edwards" <bedwards@juniper.net>
To: "'Joe Harris'" <JoeH@globaldatasys.com>; <spope@cablespeed.com>
Cc: <ccielab@groupstudy.com>
Sent: Tuesday, August 29, 2000 2:03 PM
Subject: RE: Understanding ISDN Dial Backup
> So the static routes allows you to route traffic across the link as soon
as
> the ISDN link comes up (you don't have to wait for the EIGRP neighbor to
> come up, route info to be exchanged, best path computed.)
>
> So with the "watching" feature. Does the idle timer still take effect? My
> concern is that The link will come up initially, EIGRP adj comes up, fill
> the routing table. But then the idle timer expires (EIGRP is not
> interesting), the ISDN link goes down, we miss three hellos and we tear
down
> the adj and flush the routes (after the holddown and flush timers expire).
> Then we never bring the link back up because interesting packets do not
have
> a route out the BRI interface.
>
> -----Original Message-----
> From: Joe Harris [mailto:JoeH@globaldatasys.com]
> Sent: Tuesday, August 29, 2000 11:56 AM
> To: Brian Edwards; Joe Harris; spope@cablespeed.com
> Cc: ccielab@groupstudy.com
> Subject: RE: Understanding ISDN Dial Backup
>
>
> It's not really a "have to" situation. You see if for instance you are
using
> a 172.16.0.0 address space. When you define a network command under your
> "router eigrp <as>" you are going to do it for a classfull network
> (172.16.0.0). Lets say that your ISDN is using a 172.16.32.0/30, well your
> network command covers this .32.0 network. When the route drops from the
> route table and your bri (or serial or whatever type of interface you are
> using for backup) kicks in the router will automatically creates neighbor
> routes by default; that is, it automatically sets up a route to the peer
> address on a point-to-point interface when the PPP IPCP negotiation is
> completed. The static route is there for demonstration purposes. Set it up
> in lab, it will work without defining a floating static. Think of it from
an
> OSPF setup (although it does not support OSPF just yet).
> If you have your OSPF ISDN area defined under your "router ospf <as>"
> command and you use your ISDN to backup the router's DLCI connection to
the
> network. After you put your ISDN interface in a backup state, you don't
have
> to define a floating static route, your "network <address wildcard-mask>
> area <area>" command just took care of routing for you.
>
>
> -----Original Message-----
> From: Brian Edwards [mailto:bedwards@juniper.net]
> Sent: Tuesday, August 29, 2000 1:21 PM
> To: 'Joe Harris'; spope@cablespeed.com
> Cc: ccielab@groupstudy.com
> Subject: RE: Understanding ISDN Dial Backup
>
>
> Joe,
> I checked out the web page and it shows that you still need a floating
> static to the "watched" prefix.
>
> ip route 10.0.0.0 255.0.0.0 BRI0 150 <----route to
> remote "floating static route"
>
> Any way around this? Maybe a sceondary IP address of 10.255.255.254/8 on
> bri0 (but you can't float a connected). Maybe a RIP and SNAPshot routing
to
> advertise the 10/8 over the BRI?
>
> /Brian
>
>
> -----Original Message-----
> From: Joe Harris [mailto:JoeH@globaldatasys.com]
> Sent: Tuesday, August 29, 2000 10:18 AM
> To: spope@cablespeed.com
> Cc: ccielab@groupstudy.com
> Subject: RE: Understanding ISDN Dial Backup
>
>
> Use a "dialer watch-list", but it can only be used with eigrp.
>
> http://www.cisco.com/warp/public/793/access_dial/backupwatch.html
>
> -Joe H
>
>
> -----Original Message-----
> From: spope@cablespeed.com [mailto:spope@cablespeed.com]
> Sent: Tuesday, August 29, 2000 12:03 PM
> To: CCIE (E-mail)
> Subject: Understanding ISDN Dial Backup
>
>
> 1. Dialer Profiles w/ backup interface
>
> 2. Backup interface
>
> 3. Floating static routes
>
> I keep reading that you can't use static routes which leaves me with two
> other options. And I read you can't use backup interfaces What else is
> there besides dynamic routing??
>
>
> Thanks for any input.
>
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