Re: BGP auto- summary not working as expected

From: ccie2be (ccie2be@nyc.rr.com)
Date: Sat May 17 2003 - 10:22:04 GMT-3

• Next message: nivanak: "when does ccie-lab update ?"
• Previous message: jfaure@sztele.com: "Dialer watch "time-range" based"
• Maybe in reply to: ccie2be: "BGP auto- summary not working as expected"
• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] [ attachment ]

Hi Kamal,

What you said is what I had thought. So, why then, in the 2 examples below,
is the subnet 10.6.6.0 showing up in rtrB's bgp table? According to what
you're saying it shouldn't be there, yet there it is. thanks, Jim
  ----- Original Message -----
  From: benmekki kamal
  To: ccie2be
  Sent: Saturday, May 17, 2003 8:38 AM
  Subject: Re: BGP auto- summary not working as expected

  Hello
  By default, BGP does not accept subnets redistributed from Interior Gateway
Protocol (IGP). To advertise and carry subnet routes in BGP, use an explicit
network command or the no auto-summary command. If you disable
auto-summarization and have not entered a network command, you will not
advertise network routes for networks with subnet routes unless they contain a
summary route.

  http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/ip_
r/iprprt2/1rdbgp.htm#1017476

  Regards,

  Kamal

  ccie2be <ccie2be@nyc.rr.com> wrote:
    Hi Group,

    I have 2 routers - rtr A and rtr B - in the same AS.

    rtrA's config

    int s0
    ip addr 10.6.6.6 255.255.255.0

    int e0
    ip addr 172.16.1.6 255.255.255.0

    router BGP 12
    nei 172.16.1.5 remote-as 12
    redist connected

    Here's the issue: On rtr B, both routes, 10.0.0.0 and 10.6.6.0, are in
the
    bgp table regardless of whether auto-sum is enabled or disabled. Why is
that?
    I expected only route 10.0.0.0 to be in rtrB's table when auto-summary is
    enabled which is the default.

    The same thing happens when rtrA is configured like this:

    router bgp 12
    nei 172.16.1.5 remote-as 12
    net 10.6.6.0 mask 255.255.255.0

    From this experiment, it seems that auto-sum doesn't do anything. I
assume
    I'm doing sonething wrong or I don't quite understand the way auto-summary
is
    suppose to work. Can somebody set me straight! ?

    Thanks in advanced.

-----------------------------------------------------------------------------
-
  Do You Yahoo!? -- Une adresse @yahoo.fr gratuite et en frangais !
  Testez le nouveau Yahoo! Mail

• Next message: nivanak: "when does ccie-lab update ?"
• Previous message: jfaure@sztele.com: "Dialer watch "time-range" based"
• Maybe in reply to: ccie2be: "BGP auto- summary not working as expected"
• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] [ attachment ]

This archive was generated by hypermail 2.1.4 : Mon Jun 02 2003 - 15:13:44 GMT-3