I am considering running route reflectors in our current network topology of 20 od MX80's however all current devices are active traffic forwarders.

from a scaling perspective RR makes logical sense however , I have always been warned that RR should be configured on the High end P devices or be dedicated standalone RR's

can someone kindly provide some insight into how / what decision need to be make in deploying forwarding / non forwarding RR's

Thanks Ian


There are technical and operational considerations.

The technical consideration is anticipating or determining how much load the RR platform will be subjected to. Are you going to be carrying 100>1000>??? of routes? Will there be lots of churn? Generally, RRs obtain a complete copy of the BGP RIB. So if you have a churn event, it propagates to all of your route reflectors. If they are also in the forwarding path, you can wind up with problems in your data path. Specific to the MX80, the RE isn't the best for RR services with lots of routes. I wouldn't combine them.

Operationally, are you OK with fate sharing your RR and your data plane? Consider: maintenance, change policy. If you don't have a change policy, are you hiring? Kidding.

I can tell you that in the past I have combined my P node and RR. I did so on a larger platform but I also lsys'd the box so that the RR portion of the router could lift right out when I decided to go to discrete RRs.

If I had a greenfield to build now, I would either get stub 240s with dual x64 REs or run it on a server running something like Vyatta. In some topologies, I'm not even sure I would put the RR in the IGP. One less thing to go wrong.

  • well essentially is a max 40 VRF topology , with mostly RF1918 addressing and by large the smallest subnets are /22 and i try use aggregate where possible/feasible. What issues have you seen with MX80 ? – DrBru Jun 15 '13 at 18:59

If RR isn't close by in the forwarding path then it might reflect sub-optimal route to your PE. In future this problem will be fixed by BGP-ORR

If you are running MPLS network, then you should also consider if your core should be BGP free or not. Benefit of BGP free core is that it won't crash next time there is parser bug for BGP UPDATE message. Problem with BGP free core is that either your PE boxes need to have full-table or you'll have sub-optimal default-route.

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