===============
twenty>en
twenty#conf t
Enter configuration commands, one per line. End with CNTL/Z.
twenty(config)#router isis
twenty(config-router)#?
Router configuration commands:
default Set a command to its defaults
default-information Control distribution of default information
distance Define an administrative distance
distribute-list Filter networks in routing updates
exit Exit from routing protocol configuration mode
help Description of the interactive help system
maximum-paths Forward packets over multiple paths
no Negate a command or set its defaults
passive-interface Suppress routing updates on an interface
redistribute Redistribute information from another routing
protocol
summary-address Configure IP address summaries
traffic-share Algorithm for computing traffic share for
alternate
routes
twenty(config-router)#net 01.0000.0000.0020.00
^
% Invalid input detected at '^' marker.
twenty(config-router)#exit
twenty(config)#exit
twenty#wr t
00:01:50: %SYS-5-CONFIG_I: Configured from console by console
Building configuration...
Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname twenty
!
!
ip subnet-zero
!
!
!
interface Serial0
ip address 10.0.20.20 255.255.255.0
no ip directed-broadcast
encapsulation x25
no ip mroute-cache
no keepalive
x25 address 200
x25 map ip 10.0.20.10 100
clockrate 4000000
no cdp enable
!
interface Serial1
ip address 10.0.22.20 255.255.255.0
no ip directed-broadcast
encapsulation x25 dce
no ip mroute-cache
x25 address 201
x25 map ip 10.0.22.40 401
no cdp enable
!
interface TokenRing0
ip address 10.0.10.20 255.255.255.0
no ip directed-broadcast
ring-speed 16
no cdp enable
!
interface TokenRing1
ip address 10.0.13.20 255.255.255.0
no ip directed-broadcast
ring-speed 16
no cdp enable
!
ip classless
!
no cdp run
!
line con 0
transport input none
line aux 0
line vty 0 4
login
!
end
twenty#
===============================
In other words: huh?
router isis doesnt appear in the config, and theres no NET command.
The IOS version is 12.0 for this 2500 router. I have another 2500 with
11.2 IOS where ISIS works.
Its tough to believe my IOS image is bad because I also have a 1602:
===============================
seventy#conf t
Enter configuration commands, one per line. End with CNTL/Z.
seventy(config)#router isis
seventy(config)#router isis
seventy(config)#exit
seventy#wr t
Building configuration...
Current configuration:
!
version 11.3
no service password-encryption
!
hostname seventy
!
!
partition flash 2 6 6
!
!
interface Ethernet0
no ip address
shutdown
!
interface Serial0
ip address 10.0.25.70 255.255.255.0
no ip mroute-cache
service-module 56k clock source internal
service-module 56k network-type dds
!
ip classless
--More--
%SYS-5-CONFIG_I: Configured from console ! e
line con 0
line vty 0 4
login
!
end
seventy#
=================================
which doesnt even go into the ISIS config mode... this one is 11.3
IOS.. and another 1602 with 12.0 IOS:
================================
sixty>en
sixty#conf t
Enter configuration commands, one per line. End with CNTL/Z.
sixty(config)#router isis
sixty(config)#exit
sixty#wr t
Building configuration...
Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname sixty
!
!
ip subnet-zero
!
!
!
interface Ethernet0
ip address 10.0.14.60 255.255.255.0
no ip directed-broadcast
no cdp enable
!
interface Serial0
ip address 10.0.25.60 255.255.255.0
no ip directed-broadcast
--More--
04:44:46: %SYS-5-CONFIG_I: Configured from console service-module 56k
clock sou
rce line
service-module 56k network-type dds
no cdp enable
!
ip classless
!
no cdp run
!
line con 0
transport input none
line vty 0 4
login
!
end
sixty#
============================
Do I have a pile of dysfunctional routers by chance or is this a
conspiracy by cisco to promote EIGRP? 
Ive done many things to these routers, and their IOSes seem robust and
capable of various framerelay, tunnel, OSPF, X25, access-list etc
configs. I have GOT to be missing something here.
