BGP/EIGRP Best Practice

[brandon.m.strode1]

I have a question regarding best practice when it comes to using BGP and EIGRP for dynamic routing.  We are building a new infrastructure.  We have a Home office and branches that connect back to the home office via AVPN.  I am currently building the routing from a branch to the home office.  We have acisco 3650 running ipservices license and is using EIGRP between it and the branch router.  The branch itself is hosting a class b network.  We are running bgp between the branch router and the home office.  The switch is hosting all users/networks and is advertising said networks to the router via the eigrp.  Then to advertise those networks out I was going to redistribute eigrp into BGP allowing the router to advertise the networks that way.  I was told however by a consultant that is not the best practice.  Instead best practice is to send routes via eigrp and then on the router put a static route for the same networks pointing to null 0 and add a network statement for said networks into bgp configuration.  See below for the the way I was planning on configuring it and the way that the consultant said was best practice.  What is best practice in this situation?  

Branch Router (Consultant Way)                                  Branch Switch (Consultant Way)

router bgp 22222                                                           router eigrp 10
bgp log-neighbor-changes                                              network 10.120.0.0 0.0.255.255 
network x.x.0.0 mask 255.255.0.0                                   network 192.168.188.92 0.0.0.3 
neighbor x.x.x.x remote-as 11111                                   passive-interface default
neighbor x.x.x.x allowas-in                                              no passive-interface GigabitEthernet1/0/48
neighbor x.x.x.x soft-reconfiguration inbound

ip route x.x.0.0 255.255.0.0 null0                                     ip route 0.0.0.0 0.0.0.0 x.x.x.x

Branch Router (My Way)                                     Branch Switch (My Way)

router bgp 22222                                               router eigrp 10
bgp log-neighbor-changes                                network 10.111.0.0 0.0.255.255 
redistribute eigrp 10                                           passive-interface default
neighbor x.x.x.x remote-as 11111                     no passive-interface GigabitEthernet1/0/48
neighbor x.x.x.x allowas-in
neighbor x.x.x.x soft-reconfiguration inbound     iproute 0.0.0.0 0.0.0.0 x.x.x.x

[mattjones03]

Hi,

Thanks for the information provided;

The option of using the static route would work, however the objective here is to get the route that you require to advertise into the RIB of the branch router. Either option would work in that instance. The issue in using the static route approach can cause some traffic to be discarded if the static route defined does not match all subnets you wish to advertise.

As long as you are running EIGRP on both the branch switch, and branch router you would not require to redistribute EIGRP into BGP, as the subnet would be already in the RIB of the branch router as long as EIGRP advertisements are working correctly.

You would need to define a network statement within BGP to enable this to be advertise, and ensure that this statement includes all the networks you wish to advertise from that specific branch.