Re: rd (route distinguisher) in mpls l3vpn

The Route Targets represent the VPN.

For every export of a Route Target, some device needs to Import it (and vice
versa). That is why it is recommended that you SHOULD create at least one
route target that you are both importing and exporting that is the same.

Example:

R1
Ip vrf TST
Rd 65000:20
Rt import 1:10
Rt export 1:10

R2
Ip vrf TST2
Rd 65000:30
Rt import 1:10
Rt export 1:10

R1 is exporting 1:10 and R2 is importing 1:10, therefore the routes that are
local and being advertised from R1 should be received by R2.

R2 is exporting 1:10 and R1 is importing 1:10, therefore the routes that are
local and being advertised from R2 should be received by R1.

It would have also worked if the Configuration looked this way:

R1
Ip vrf TST
Rd 65000:20
Rt import 1:10
Rt export 1:50

R2
Ip vrf TST2
Rd 65000:30
Rt import 1:50
Rt export 1:10

It is just addinging for complexity when you may not need it.
Of Course, on a CCIE exam, ALL BETS are off! You need to understand how it
works.
Get it!!!!

Paul

-- 
Paul Negron
CCIE# 14856 CCSI# 22752
Senior Technical Instructor
> From: Aaron <aaron1_at_gvtc.com>
> Date: Sat, 10 Mar 2012 15:57:00 -0600
> To: 'Paul Negron' <negron.paul_at_gmail.com>, 'CCIE GROUPSTUDY'
> <ccielab_at_groupstudy.com>
> Subject: RE: rd (route distinguisher) in mpls l3vpn
> 
> Thanks Paul, What does make the vpn?  Is it the pe's matching up of the vrf
> instance and igp to the mp-ibgp ipv4 add fam ?  is that were the pairing
> happens?  And then the pe's rcv'd vpnv4 mpbgp nlri will lock in on the rd
> header and strip that and direct the remaining ipv4 nlri into the local vrf
> that the rd matched to?  Does this have something to do with the makings of
> the anatomy of a vpn ?  (from the perspective of one pe) ?
> 
> Aaron
> 
> 
> 
> -----Original Message-----
> From: Paul Negron [mailto:negron.paul_at_gmail.com]
> Sent: Saturday, March 10, 2012 3:45 PM
> To: Aaron; 'CCIE GROUPSTUDY'
> Subject: Re: rd (route distinguisher) in mpls l3vpn
> 
> The next hop of the route should be different, even if the RD's are the same
> on 2 different routers.
> 
> The RD's do not HAVE to be different but it is recommended that they should.
> 
> The VRF's do not HAVE to be different or the same.  It really is a matter of
> how confusing you want it to be.:-)
> 
> In either case........Neither the RD or the VRF identify the VPN.
> 
> Paul
> --
> Paul Negron
> CCIE# 14856 CCSI# 22752
> Senior Technical Instructor
> 
> 
> 
>> From: Aaron <aaron1_at_gvtc.com>
>> Reply-To: Aaron <aaron1_at_gvtc.com>
>> Date: Sat, 10 Mar 2012 15:16:25 -0600
>> To: 'Aaron' <aaron1_at_gvtc.com>, 'CCIE GROUPSTUDY' <ccielab_at_groupstudy.com>
>> Subject: RE: rd (route distinguisher) in mpls l3vpn
>> 
>> I think it's self-explanatory..how would you be able to *distinguish*
> routes
>> if they header (rd) prepended to the ipv4 prefix isn't unique from
> another.
>> 
>>  
>> 
>> So within a L3VPN..
>> 
>>  
>> 
>> Ce1----pe1----p----pe2-----ce2
>> 
>>  
>> 
>> .I understand that the pe's have the vrf and rd's within them...does the
> vrf
>> A rd of pe1 need to be different than the vrf A rd of pe2 ?
>> 
>>  
>> 
>> Aaron
>> 
>>  
>> 
>>  
>> 
>> From: Aaron [mailto:aaron1_at_gvtc.com]
>> Sent: Saturday, March 10, 2012 3:11 PM
>> To: 'CCIE GROUPSTUDY'
>> Subject: rd (route distinguisher) in mpls l3vpn
>> 
>>  
>> 
>> does the rd have to be unique?
>> 
>>  
>> 
>> Aaron
>> 
>> 
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>> 
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