Route Reflector Client Design Question

Fri May 4 10:44:12 UTC 2018

Hey Erik,

1) This messes up the design and introduces unnecessary complexity. As your issue is not directly caused by having a RR topology, I’d avoid doing that.
2) That, IMHO, would be the optimal solution, assuming you don’t have enough internal routes to overflow the TCAM of your PEs in the near future. This would also solve some potential loops if you ever want to pass unlabelled traffic.
3) That’s a very generic question with broad potential answers.
4) You could, but you’d have to evaluate that trade-off yourself ;)

Kind regards,

My thoughts and words are my own.

Spyros

On 04/05/2018, 09:02, "NANOG on behalf of Erik Sundberg" <nanog-bounces at nanog.org on behalf of ESundberg at nitelusa.com> wrote:

    I have a RR Client design question......

    CORE1-------------------2x10G-----------------------CORE2
    |                                                                                   |
    |                                                                                   |
    |                                10G Ring                                   |
    |                                                                                   |
    |                                                                                   |
    PE1----------PE2----------PE3----------PE4----------PE5

    -Core1 & Core2 are RR Reflectors with full IPV4 Tables (ASR9K)
    -MPLS LDP Enabled
    -IGP is ISIS
    -Each PE peers only with Core1 and Core2 as RR Clients with iBGP
    -PE's are only receiving a default route from the Core Routers due to TCAM size of 20K (ASR920's\ME3800's)
    -The ring does not have that much traffic on it <500m, so I do not want to use additional 10G ports on the Core's and is why I have it in a 10G U ring.
    -Primary link to the cores is via the PE1 --- CORE1 Like......... For this discussion the link between PE5 to CORE2 is set up as a backup link.

    The scenario is I have traffic between PE2 and PE3. Since the PE's are only receiving a default route from the Cores. Traffic is label switch from PE2 - PE1 - Core1 does a IP lookup at Ingress then label switches back to PE1-PE2-PE3. This ends up being 5 hops and doubling the traffic on the link to the Cores.

    My questions is how do I get traffic to go directly between the PE's without going to the Core Routers?

    1. Can I enable iBGP between the PE's in a full mesh to allow traffic between the PE's without going to the core's. Or does this break the Route Reflector model?
    2. Create a route policy on the Core's advertising routes learned from the PE's back to all the PE's on the ring.
    3. Is this one of the down sides to U Rings?
    4. Leave it alone and move on to bigger and better things....

    Thanks

    Erik

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