From: Daniel Free (danrose111@earthlink.net)
Date: Mon May 26 2003 - 03:19:03 GMT-3
Hi Tom,
Please see the following:
!
ISIS over NBMA
Frame Relay Configuration ISIS Network Type
Physical Interface Broadcast
Point to Point Sub-Interface Point to point
Point to Multi Point Sub-Interface Broadcast
!
ISIS supports two network types: broadcast and point-to-point. Should one
router on a segment decide that the network is point-to-point and another
router on the same segment decide on LAN, the adjacency formation process
will not be successful as the routers do not agree on the network type.
Indeed, in this case, one router will be using LAN hellos, the other
Point-to-Point hellos. This type of mismatch will actually affect all types
of networks and thus is not limited to NBMA networks. However, the
likelihood of it occurring on an NBMA network is much greater.
For example, in a frame network, should one decide to use point-to-point
sub-interfaces on one router and point-to-multipoint interfaces on the
other, the default ISIS Hellos transmitted will not match and the adjacency
will not be formed. This naturally assumes all other parameters like level
and area etc are configured correctly. Unlike OSPF where one can manually
override the routers default behavior with the ip ospf network command,
Cisco has no such knob in its ISIS implementation. Hence, it becomes
necessary to use the same types of interfaces on NBMA networks to ensure
that the necessary adjacencies can be formed.
!
!
So as you can see when given a scenario of configuring ISIS with one side
physical and the other a subinterface there is a good possibility of a
mismatch. Unless explicitly told not to do so I always configure this type
of scenario using a multipoint subinterface with a single map statement. If
you have to configure a physical to a point-to-point subinterface then you
will have to create a tunnel. Below is a sample config. Best of luck.
Danny
ISIS example (Physical interface to subinterface point-to-point -
Frame-Relay)
!
R2
interface Loopback0
ip address 192.168.100.1 255.255.255.0
ip router isis
!
interface Loopback1
ip address 192.168.101.1 255.255.255.0
ip router isis
!
interface Loopback2
ip address 192.168.102.1 255.255.255.0
ip router isis
!
interface Loopback3
ip address 192.168.103.1 255.255.255.0
ip router isis
!
interface Tunnel0
ip address 192.168.20.1 255.255.255.0
ip router isis
tunnel source 192.168.1.2
tunnel destination 192.168.1.3
!
interface Serial0
ip address 192.168.1.2 255.255.255.0
ip router isis
encapsulation frame-relay
no fair-queue
frame-relay map clns 223 broadcast
frame-relay map ip 192.168.1.3 223 broadcast
no frame-relay inverse-arp
!
router isis
net 49.0001.0000.0000.000b.00
!!!
R3
interface Loopback0
ip address 192.168.200.1 255.255.255.0
ip router isis
!
interface Loopback1
ip address 192.168.201.1 255.255.255.0
ip router isis
!
interface Loopback2
ip address 192.168.202.1 255.255.255.0
ip router isis
!
interface Loopback3
ip address 192.168.203.1 255.255.255.0
ip router isis
!
interface Tunnel0
ip address 192.168.20.2 255.255.255.0
ip router isis
tunnel source 192.168.1.3
tunnel destination 192.168.1.2
!
interface Serial0
no ip address
encapsulation frame-relay
no fair-queue
no frame-relay inverse-arp
!
interface Serial0.1 point-to-point
ip address 192.168.1.3 255.255.255.0
ip router isis
frame-relay interface-dlci 322
!
router isis
net 49.0001.0000.0000.000a.00
!
!!!!!!!!!!!!!!!!!!!!
----- Original Message -----
From: "Tom Young" <gitsyoung@yahoo.co.jp>
To: <ccielab@groupstudy.com>
Sent: Sunday, May 25, 2003 11:20 PM
Subject: isis sample
> Hi, group
>
> Who can give me a sample that one router use
> subinterface to connecting another one using phsical
> interface for running isis, as below
>
> RouterA S0.1---------------RouterB S0
>
> I couldn't make it out.
>
> Thanks alot
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! BB is Broadband by Yahoo! http://bb.yahoo.co.jp/
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