We have 3 internet connection, a 100FDX, 20FDX and a 1000FDX.
At the moment they are all connected to a PowerRouter732 which runs BGP and then that connects to a RB1000 that does local routing (OSPF) and VLANs. The RB1000 connects to a 10/100 switch that needs to be upgrades to a gigabit switch.
Ok, Here’s what I want to do.
Drop the 100FDX connection (1000FDX was it’s replacement) and then move the 20FDX connection to the RB1000(if it can handle BGP). Then use a RB1200 for the local router for OSPF and VLANs.
I need more ports than the 4 on the RB1000 so the RB1200 seems to be a good fit. The only concern I have is that the RB1200 is not as fast as the RB1000.
I wonder if the PowerRouter732 would be a better choice for a BGP router. ?
Is the RB1000 a better router that the RB1200?
The idea is to have two BGP router connected to each other and a local network router connected to the two BGP routers.
Which routers would up pick for this config/job?
Kinda depends on details you didn't post. There's a big difference between a router that gets a default route via BGP and announces a few aggregates vs something that will get full routing tables and needs to churn hundreds of thousands of routes.
With such wildly different circuits (20 meg vs 1 gig) it doesn't really make sense to have full routing tables, otherwise you risk very quickly overwhelming that 20 meg pipe when suddenly there's a lot of traffic to prefixes it has better (shorter) paths for. All traffic should go out the gig pipe until it fails, in which case the 20 meg pipe kicks in.
An RB750 could do that*, an RB1200 would most certainly suffice to terminate that connection, with lots of room to grow.
Another possibility is taking a default route from the gig pipe and a default plus partials for prefixes directly connected to the AS the 20 meg pipe goes. At that point it kinda depends on how many prefixes that would be, but unless it's to a huge AS with a huge number of prefixes that aren't summarized properly an RB1200 would still be perfectly fine.
The next point is how much traffic is actually going to pass through the router, and what the router will do to the traffic. You have a gig pipe, but how much traffic do you expect to pass? Neither the RB1100 nor the RB1200 realistically will sustain 600+ Mbps when given IMIX traffic. The PowerRouter probably could. Is this just going to be a border router, that does nothing but route? No NAT, no connection traffic? That will perform a lot better than a NAT router, or one that has firewall filters inspecting every packet.
An RB750 of course couldn't be a gig router, the point is that with just defaults there's so little processing for BGP that such a small router could absolutely handle it.