Hi,
I have some comments about this draft.
section
3.2. Adjacency Establishment and Maintenance
Whenever ISIS_BFD_REQUIRED is TRUE the following extensions to therules for adjacency establishment and maintenance MUST apply:o ISIS_NEIGHBOR_USEABLE MUST be TRUE before the adjacency cantransition from INIT to UP state
This rule assumes that both the BFD and IS-IS configurations are correct and they work well. But This isn't the way all
the time.
AS we know that the establishment of the BFD session is bootstraped by IS-IS,If the BFD enabled interface have two or
more address, which address should be used to create the BFD
session ? If the two addresses of the BFD session are not on
the same subnet,the BFD session will fail ,and the IS-IS adjacency can never be ceated.That is a risk.
Cisco router encodes the primary ip address of the inteface in IS-IS hello's ip interface address(es) TLV, however,Juniper
router encodes all addresses of the interface in ip interface address(es) TLV,How about the other router ?
To resove this problem,this draft should specify which address should be used .The choosed address may be included in the
BFD enabled TLV.
To avoid confusion,it is better to specify that the IS-IS must triggere BFD session establishment before the adjacency is in UP state.
There is another scenario we must consider. When the state of IS-IS adjacency is UP and the administrator trys to configure BFD
or modify
BFD
configuration, IS-IS should discard the first BFD session failure ,IS-IS can trust BFD session state only
after
BFD session has informed IS-IS a BFD session success.
Jiaxing Lan
2010-07-25
发件人： The
IESG
发送时间：
2010-07-13 02:42:14
收件人：
IETF-Announce
抄送：
isis-wg
主题： [Isis-wg] Last Call:
draft-ietf-isis-bfd-tlv (IS-IS BFD EnabledTLV) to Proposed
Standard
The IESG has received a request from the IS-IS for IP Internets WG (isis)
to consider the following document:
- 'IS-IS BFD Enabled TLV '
<draft-ietf-isis-bfd-tlv-02.txt> as a Proposed Standard
The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
ietf@xxxxxxxx mailing lists by 2010-07-26. Exceptionally,
comments may be sent to iesg@xxxxxxxx instead. In either case, please
retain the beginning of the Subject line to allow automated sorting.
The file can be obtained via
http://www.ietf.org/internet-drafts/draft-ietf-isis-bfd-tlv-02.txt
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