From: Chris Lewis \(chrlewis\) (chrlewis@cisco.com)
Date: Mon Aug 01 2005 - 14:26:40 GMT-3
In multi-topology, metric style wide is indeed required, because TLVs
used to advertise IPv6 information in link-state packets (LSPs) are
defined to use only extended metrics.
For single topology ISIS in IPv6, the documentation quotes the
following:
"When single-topology support for IPv6 is being used, either old- or
new-style TLVs may be used. However, the TLVs used to advertise
reachability to IPv6 prefixes use extended metrics. Cisco routers do not
allow an interface metric to be set to a value greater than 63 if the
configuration is not set to support only new-style TLVs for IPv4. In
single-topology IPv6 mode, the configured metric is always the same for
both IPv4 and IPv6."
So clearly not required, but probably a good idea.
Regards no adjacency-check, the documentation states the following:
Disabling IPv6 Protocol-Support Consistency Checks
This task explains how to disable protocol-support consistency checks in
IPv6 single-topology mode.
For single-topology IS-IS IPv6, routers must be configured to run the
same set of address families. IS-IS performs consistency checks on hello
packets and will reject hello packets that do not have the same set of
configured address families. For example, a router running IS-IS for
both IPv4 and IPv6 will not form an adjacency with a router running
IS-IS for IPv4 or IPv6 only. In order to allow adjacency to be formed in
mismatched address-families network, the adjacency-check command in IPv6
address family configuration mode must be disabled. This command is
designed for use only in special situations. Please read the following
note before configuring this task.
------------------------------------------------------------------------
--------
Note Disabling the adjacency-check command can adversely affect your
network configuration. Enter the no adjacency-check command only when
you are running IPv4 IS-IS on all your routers and you want to add IPv6
IS-IS to your network but you need to maintain all your adjacencies
during the transition. When the IPv6 IS-IS configuration is complete,
remove the no adjacency-check command from the configuration.
------------------------------------------------------------------------
---------
So I guess use with caution :)
Chris
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
gladston@br.ibm.com
Sent: Monday, August 01, 2005 11:42 AM
To: Chris Lewis (chrlewis)
Cc: san; ccielab@groupstudy.com
Subject: RE: IS-IS for IPv6 over Frame-Relay
Thanks for the replies,
Thanks Chris. That was exactly the cause. I was playing with many
combinations and IOS did not responded consistently. Than, reloaded it
and the problem goes alway.
Reading 'Cisco Self Study' by Rigis and IPv6 Cisco Library and testing,
I am not sure if get it right. Would you agree with these statement?
Adjacency Check
'no adjacenty-check' -> does not loose adjaceny when one router is
configured with 'ip router isis' and ipv6 router isis' and the neighbor
is configured with only 'ipv6 router isis'
A single SPF is still used, routers on the same area or domain must
still have the same set of address families. 'no-adjacency-check' is to
be used only during transition from IPv4 only to IPv4-IPv6
Multitopology IPv6 IS-IS
'multi-topology' -> ipv6 will have an independent topology; It is not
required that all routers on the same area or domain have the same set
of protocols; that is, router x can be configured with IS-IS IPv6 only
and routers Y/Z can be configured with IS-IS IPv4-IPv6.
'metric-style wide' is not an option, it is a required command if using
multitopology.
Cordially,
------------------------------------------------------------------
Gladston
"Chris Lewis \(chrlewis\)" <chrlewis@cisco.com>
01/08/2005 13:02
To
Alaerte Gladston Vidali/Brazil/IBM@IBMBR cc
Subject
RE: IS-IS for IPv6 over Frame-Relay
Maybe a re-load is required, ISIS uses a single SPF for v4 and v6, and
therefore it needs all routers in the area to have the same combination
of v4 and v6 running, taking one off may cause things to get confused,
at least temporarily :)
Chris
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
gladston@br.ibm.com
Sent: Monday, August 01, 2005 10:35 AM
To: ccielab@groupstudy.com
Subject: IS-IS for IPv6 over Frame-Relay
If I remove 'ip router isis', IS-IS IPv6 does not work.
Have you seem this?
I confirmed that only IPv6 are enable on R1 and R4, entered 'no
adjacency-check'(just to be sure it was not the cause, although there is
no logic), but no lucky.
Tests with 'ip router isis' and 'ipv6 router isis':
Rack2R1#sh ipv6 route
I1 2001:148:5:4::/64 [115/20]
via FE80::230:94FF:FED8:FDE0, Serial0/0.14
L FE80::/10 [0/0]
via ::, Null0
C FEC0:148:5:14::/64 [0/0]
via ::, Serial0/0.14
L FEC0:148:5:14::1/128 [0/0]
via ::, Serial0/0.14
L FF00::/8 [0/0]
via ::, Null0
Rack2R1#
Rack2R1#sh clns ne det
System Id Interface SNPA State Holdtime Type
Protocol
Rack2R4 Se0/0.14 DLCI 104 Up 24 L1L2
IS-IS
Area Address(es): 49.0014
IP Address(es): 148.5.14.4*
IPv6 Address(es): FE80::230:94FF:FED8:FDE0
Uptime: 00:00:14
NSF capable
Tests with 'ipv6 router isis' (removed ip router isis):
Rack2R1(config)#int ser 0/0.14
Rack2R1(config-subif)#no ip router isis
Rack2R1(config-subif)#do i ip router isis Rack2R1(config-subif)#
Rack2R4(config)#int ser 0/0
Rack2R4(config-subif)#no ip router isis
Rack2R4(config-subif)#do i ip router isis Rack2R4(config-subif)#
Rack2R1#sh clns ne
Rack2R1#sh clns int ser 0/0.14
Serial0/0.14 is up, line protocol is up
Checksums enabled, MTU 1500, Encapsulation FRAME-RELAY ERPDUs enabled,
min. interval 10 msec.
CLNS fast switching enabled
CLNS SSE switching disabled
DEC compatibility mode OFF for this interface Next ESH/ISH in 28 seconds
Routing Protocol: IS-IS Circuit Type: level-1-2 Interface number 0x2,
local circuit ID 0x100
Level-1 Metric: 10, Priority: 64, Circuit ID: Rack2R1.00
Level-1 IPv6 Metric: 10
Number of active level-1 adjacencies: 0
Level-2 Metric: 10, Priority: 64, Circuit ID: Rack2R1.00
Level-2 IPv6 Metric: 10
Number of active level-2 adjacencies: 0
Next IS-IS Hello in 7 seconds
if state DOWN
Rack2R4(config-if)#do sh clns ne
System Id Interface SNPA State Holdtime Type
Protocol
1111.1111.1111 Se0/0 DLCI 401 Up 271 IS
ES-IS
Configs:
Rack2R1#sh run int ser 0/0.14
interface Serial0/0.14 point-to-point
bandwidth 128
ip address 148.5.14.1 255.255.255.0
ipv6 address FEC0:148:5:14::1/64
ipv6 router isis
frame-relay interface-dlci 104
Rack2R4(config-if)#do sh run int ser 0/0
interface Serial0/0
bandwidth 38
ip address 148.5.14.4 255.255.255.0
encapsulation frame-relay
ipv6 address FEC0:148:5:14::4/64
ipv6 router isis
frame-relay map clns 401 broadcast
frame-relay map ipv6 FEC0:148:5:14::1 401 broadcast frame-relay map ip
148.5.14.1 401 broadcast no frame-relay inverse-arp
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