which BGP4+ used

[Masaki Hirabaru]

Kunihiro and Pedro,

Thanks for letting me know. I haven't seen the -00 version, so I
got confused. I'm still writing this by analyzing a BGP4+ packet
I'm receiving rather than looking at the -00 version. So, the
following differences may not cover all.

1) There is a length field, NLRI Length (2 octets) in Kunihiro's
explanation, which doesn't exist in the -01 version.

Both MP_REACH_NLRI (Type Code 14) and MP_UNREACH_NLRI (Type Code
15) have this 2 octets length field right before Network Layer
Reachability Information (variable) or Withdrawn Routes
(variable), respectively.

2) The Length of Next Hop Network Address (1 octet) in
MP_REACH_NLRI (Type Code 14) has a value 32; A global-scope
address (16 octets) and a link-local address (16 octets) follow.

I think that in the -01 version, next hop address should be one.

Kunirhiro, my BGP4+ code is based on the same one Gated has.  I
need to connect the 6bone with BGP4+, so I have no choice at the
moment. So, probably I'd better put some configuration option to
switch a version depending on a peer.

Does 6bone has a plan to migrate to the -01 version? I don't
think there is any version information to distinguish in BGP4+
OPEN message, so I think we may need to have a schedule if we
want to update. Anyway, thanks. I'm clear now.

Masaki

> Return-Path: majordom@ISI.EDU
> Message-Id: <199710170621.PAA18946@rs.digital-magic.co.jp>
> From: kunihiro@zebra.org
> To: 6bone@ISI.EDU
> Subject: Re: which BGP4+ used
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> Date: Fri, 17 Oct 1997 15:21:56 +0900
> Sender: owner-6bone@ISI.EDU
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> 
> >I know a version of BGP4+ is running over 6bone, but it seems
> >different from draft-ietf-idr-bgp4-multiprotocol-01.txt.  I'm now
> >testing our BGP4+ code with cisco at one of 6bone backbone sites,
> >but its BGP4+ is apparently different from the draft. I'm afraid
> >I might miss something new. Is there any updated spec?
> 
> I'm thinking about a same problem.  It seems that some current running
> code conforms draftr-ietf-idr-bgp4-multiprotocol-00.txt (include two
> octet NLRI length field).  Many people are thinking that it is also
> important conforming current vendor's beta version implemetation.  But
> I'm not sure vedor implementation.
> 
> I have seen three types of BGP4+ packet.  Below description assumes
> SNPA is zero.
> 
> 1. o gated-bgp4+ default (without -DBATES_LAST_DRAFT)
>   .. no SAFI 
>   +--------------------------------+
>   | AFI (2 octets)                 |
>   +--------------------------------+
>   | Length of NextHop (1 octet)    |
>   +--------------------------------+
>   | Address of NextHop (variable)  |
>   +--------------------------------+
>   | Number of SNPAs (1 octet = 0)  |
>   +--------------------------------+
>   | NLRI Length (2 octets)         |
>   +--------------------------------+
>   | NLRI (variable)                |
>   +--------------------------------+
> 
> 2. draft-ietf-idr-bgp4-multiprotocol-00
>    o gated-bgp4+ (with -DBATES_LAST_DRAFT )
>    o MRT
>    o zebra (with draft-00 option)
>    .. with NLRI length
>   +--------------------------------+
>   | AFI (2 octets)                 |
>   +--------------------------------+
>   | SAFI (1 octet)                 |
>   +--------------------------------+
>   | Length of NextHop (1 octet)    |
>   +--------------------------------+
>   | Address of NextHop (variable)  |
>   +--------------------------------+
>   | Number of SNPAs (1 octet = 0)  |
>   +--------------------------------+
>   | NLRI Length (2 octets)         |
>   +--------------------------------+
>   | NLRI (variable)                |
>   +--------------------------------+
>   
> 3. draft-ietf-idr-bgp4-multiprotocol-01
>    o zebra
>   ... rid of NLRI length
>   +--------------------------------+
>   | AFI (2 octets)                 |
>   +--------------------------------+
>   | SAFI (1 octet)                 |
>   +--------------------------------+
>   | Length of NextHop (1 octet)    |
>   +--------------------------------+
>   | Address of NextHop (variable)  |
>   +--------------------------------+
>   | Number of SNPAs (1 octet = 0)  |
>   +--------------------------------+
>   | NLRI (variable)                |
>   +--------------------------------+
> 
> IMHO, the best thing is moving toward to draft-ietf-idr-bgp4-multiprotocol-01
> specification.
> --
> Kunihiro Ishiguro