Re: BGP Highest RID..initiate or build the IBGP TCP connection

Just ask yourself, why does this "rule" exists at all, and it should be much
clearer.

It is only a method for the case when both peers establish the sessions, and
you have two sessions going at the same time.
Because you don't want duplicate sessions, you want only one to stay up.

Although Highest/lowest RID you mentioned is one method to clear this
session collision, you are not correct that it is not mentioned in RFC.
Whole section 6.8 is dedicated to this. Check out this excerpt:

6.8. BGP Connection Collision Detection

   If a pair of BGP speakers try to establish a BGP connection with each
   other simultaneously, then two parallel connections well be formed.
   If the source IP address used by one of these connections is the same
   as the destination IP address used by the other, and the destination
   IP address used by the first connection is the same as the source IP
   address used by the other, connection collision has occurred. In the
   event of connection collision, one of the connections MUST be closed.

   Based on the value of the BGP Identifier, a convention is established
   for detecting which BGP connection is to be preserved when a
   collision occurs. The convention is to compare the BGP Identifiers
   of the peers involved in the collision and to retain only the
   connection initiated by the BGP speaker with the higher-valued BGP
   Identifier.

On Tue, Apr 7, 2009 at 4:12 PM, dave dave <funccie_at_gmail.com> wrote:

> Hi Brian, Scott & GS,
>
> I have gone throgh the IE Tech Lab v4.x & v5.0. I have also labbed the
> things on dynagen & i found that highest bgp router-id initiate the session
> on TCP port 179 to the IBGP peer. I also observe if i do the router-id
> change the highest router-id is always show the session is initiated as
> well
> as form from the heighest router-id IBGP peer to remore IBGP peer on the
> TCP
> port 179.
>
>
> I have seen the the 12k ciso router as well as ERX Juniper router not show
> that the session is ALWAYS form between the heighest router id port xyz to
> per port 179, who is having lowest router-id.
>
>
> It confused me looot...I also not found this mention in the RFC 4271..
>
> Is it session initiation or session build up ???? i am confuse :(
>
> Narbik: i see you online..so any quick answer to clear my confusion
>
> Regards
> Dave
>
>
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