[j-nsp] BGP RR in MPLS VPN

Ihsan Junaidi Ibrahim ihsan at isp.time.net.my
Wed Feb 14 05:38:32 EST 2007


Hi,

It is configured as a discard route.

ihsan at glsfb2-mbone> show configuration routing-options rib inet.3 
static {
    route 10.254.250.0/24 discard;
} 

And this is what I got on one of the PEs. If I configured an LSP to the RRs,
then the route shows up on the table. However regardless of the route state,
VPN next-hops are resolvable.

ihsan at smtnw-mbone> show route table inet.3 10.254.250.0 hidden extensive 

inet.3: 25 destinations, 48 routes (24 active, 0 holddown, 2 hidden)
10.254.250.0/24 (2 entries, 0 announced)
         BGP    Preference: 170/-101
                Next hop type: Unusable
                Next-hop reference count: 2
                State: <Hidden Int Ext>
                Local AS:  9930 Peer AS:  9930
                Age: 2d 6:52:13 
                Task: BGP_9930.10.254.250.2+179
                AS path: I
                Route Label: 250864
                Localpref: 100
                Router ID: 10.254.250.2
                Indirect next hops: 1
                        Protocol next hop: 10.254.250.2
                        Push 250864
                        Indirect next hop: 0 -
         BGP    Preference: 170/-101
                Next hop type: Unusable
                Next-hop reference count: 2
                State: <Hidden Int Ext>
                Local AS:  9930 Peer AS:  9930
                Age: 2d 6:49:49 
                Task: BGP_9930.10.254.250.1+179
                AS path: I
                Route Label: 475232
                Localpref: 100
                Router ID: 10.254.250.1
                Indirect next hops: 1
                        Protocol next hop: 10.254.250.1
                        Push 475232
                        Indirect next hop: 0 -

-----Original Message-----
From: Sean Clarke [mailto:sean at clarke-3.demon.nl] 
Sent: Wednesday, February 14, 2007 5:35 PM
To: Ihsan Junaidi Ibrahim
Cc: 'Ariff Premji'; juniper-nsp at puck.nether.net
Subject: Re[2]: [j-nsp] BGP RR in MPLS VPN

Hi Ihsan,

  How have you put the route into inet.3 ?
  I generally  see it configured as a "discard" route, then it's not
  hidden

Cheers
Sean
--

Not so long ago you wrote : 
IJI> Thanks Ariff,

IJI> I've put in the prefix consisting of our loopback IP range into 
IJI> inet.3 and now the VPNs next-hops are resolvable directly without 
IJI> creating the LSPs to the RR.

IJI> One thing I'm curious is that the prefix is listed as hidden in 
IJI> inet.3. Is this the intended behaviour?

IJI> -----Original Message-----
IJI> From: Ariff Premji [mailto:premji at speakeasy.net]
IJI> Sent: Monday, February 12, 2007 10:52 AM
IJI> To: Ihsan Junaidi Ibrahim
IJI> Cc: juniper-nsp at puck.nether.net
IJI> Subject: Re: [j-nsp] BGP RR in MPLS VPN

IJI> Not sure if you've explore this option or not.  You dont need to 
IJI> setup LSPs to your RR.  You can place a 0/0 route in inet.3 on the 
IJI> RR so that all learnt routes appear as resolvable and hence reflected.

IJI> Take a look at the RR config at:

IJI> http://www.apricot2006.net/slides/tutorial/tuesday/L3VPN_migration.
IJI> zip

IJI> -A

IJI> On Feb 10, 2007, at 2:16 PM, Ihsan Junaidi Ibrahim wrote:

>> Hi all,
>>
>> Bringing up an old topic. :)
>>
>> I'm having problem creating an LSP on one of my RR to it's own lo0.  
>> The reason I'm doing this is to propagate our network loopback prefix 
>> to the rest of the PEs, without creating full mesh of LSPs between 
>> the PEs and the RRs.
>>
>> ihsan at kenanga# show label-switched-path to-self to 10.254.250.2; 
>> install 10.254.250.0/24;
>>
>> And CSPF kept mentioning empty route to the egress.
>>
>> ihsan at kenanga# run show mpls lsp ingress name to-self extensive 
>> Ingress LSP: 17 sessions
>>
>> 10.254.250.2
>>   From: 0.0.0.0, State: Dn, ActiveRoute: 0, LSPname: to-self
>>   ActivePath: (none)
>>   LoadBalance: Random
>>   Encoding type: Packet, Switching type: Packet, GPID: IPv4
>>   Primary                    State: Dn, No-decrement-ttl
>>     Will be enqueued for recomputation in 10 second(s).
>>     1 Feb 11 06:08:58 CSPF failed: empty route 10.254.250.2
>>   Created: Sun Feb 11 06:08:55 2007
>> Total 1 displayed, Up 0, Down 1
>>
>> I was also recommended to create the LSP to another RR and vice- 
>> versa (to get the prefix installed in inet.3) but I want to avoid 
>> that because in the event of the dest RR failing (we only have 2 
>> RRs), then the NLRI will be marked inactive.
>>
>> Any ideas anyone?
>>
>> /ihsan
>>
>>> Hi Guys,
>>>
>>> What you are looking for is that in order for the l3bgp table to 
>>> have active routes to pass to the other reflector clients the next 
>>> hop for all PE¹s in the vpn global table (l3bgp table) must be a LSP 
>>> learned route.  In the traditional sense this would require a full 
>>> mesh of lsp¹s to the RR and a full mesh of lsp¹s to each PE.  A 
>>> simple work around for this in order to not have lsp¹s going to the 
>>> RR from each PE is to build a fake LSP on the RR to it¹s own 
>>> loopback. Then install 0/0 under this LSP then their will be a 0/0 
>>> entry in inet.3 which will resolve all next-hops for the PE routes 
>>> in the Global vpn table. Of course this will not actually forward 
>>> traffic. The sole purpose of this 0/0 is to resolve routes and 
>>> subsequently allow the RR to advertise the routes to other clients that
are now active.
>>>
>>>
>>> I hope this clears things UP...
>>>
>>> Cheers,
>>>
>>> Gary Hauser
>>> JNCIE #12, CCIE # 4489
>>>
>>
>> _______________________________________________
>> juniper-nsp mailing list juniper-nsp at puck.nether.net 
>> https://puck.nether.net/mailman/listinfo/juniper-nsp


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