Hi all.
Currently I have one upstream and so didn’t have any need for BGP; BR450G was OK for me.
Now I’m going to have second upstream and want to establish BGP peering with both ISPs.
What hardware would be fine for me? I’m going to recieve two full view tables to fully take advantages of 2 ISP connections.
Thanks.
Two full feeds requires a lot of RAM. You need router with 512MB of ram, like RB1000.
RB450G can handle only one feed.
OK, and so what about 3 full feeds? Is there any RouterOS-capable hardware? Or is there any way to upgrade memory in RBs?
You can change memory in RB1000. It uses SODIMM modules.
The RB1000 goes up to a maximum 1.5GB of RAM using a single 2GB DDR2 SODIMM.
Tom
First, thanks to all for replies.
So, would RB1000 really do the job? Or is it a cheap way and maybe I should look for something else (maybe x86)?
The RB1000 doesn’t do well with multiple BGP peers carrying full routes. Go with at least a dual core processors X86.
I have to agree with believewireless, it takes a very long time to receive and process the full bgp table, at which point the CPU is used 100% (and if you use ospf or other timing sensitive stuff, they will timeout).
X86 would be fine, but i didnt got around to replace the RB1000 i have.
synologic,
believewireless,
Thanks for replies. What is the actual processing time? 5 minutes to process routes at boot time (and then just forget about the router for year or two 
) would be ok.
Abram, please forget about full feeds! receive only default routes
that kinda fucks up the whole idea behind bgp, right? why should i limit myself if there is hardware available that can cope with a real full view?
limit? what kind of limiting do you mean? isn’t ‘full view’ just a loud words for those whose server is RB450G and it’s enough?.. so you simply get only default routes from uplink providers - and then announce your subnets with different prepend to these uplinks
Abram, please forget about full feeds! receive only default routes
it is usefull only when you intend to use the second BGP peer as a backup one (and the ISPs doesn’t want to use OSPF for it). But it will work as expected only when link to main ISP will go down. You will receive the default route even half on an Internet will have no connection to your main upstream ISP - so you will not be able to access these prefixes. In the case of 2 full views you will access the prefixes via second upstream…
absolutely wrong. if you announce all your prefixes to all your uplinks, but with different prepend - you get full backup, and at the same time you can control, via which uplinks you will receive the traffic for those subnets
Agree with Chupaka! Anyway you aren’t going to use the routes you are receiving in a full view table.. Your Router can choose the route to go out by a policy routing you choose with only the default routes. And you can load balance /backup just subnetting your announces ( Announce on both peers your whole network [you got a /22 IE?] then announce it again with subnets [4x /24] to the prefered link. And Et voilà the traffic comes from that link! If that one goes down, the backup link has still the routes to your network [the /22]..
You need BGP full routing tables only if you have to do transport between AS [Carrier]
Ask to a consultant for further info about BGP tbh..
Hope it helps.
Edit: Chupaka, prepend isn’t always working with peering with different AS
well, even in the worst case (many different ASes on one uplink to the ~tier1, almost direct connection via second uplink) bgp-prepend=5 (10, 20, etc 
) saves the situation =)
lol, the “full views” argument…
I come accross people wanting “full views” on a regular basis, when I probe further they have never been able to give a valid answer why.
Generally you will only need to receive a default route from your upstream peers, use a route-map/policy filter to pad the secondary path and then as Chupaka said pre-pend your AS on your secondary path.
So, you insert a default route into your network and propagate the static route? If the largest subnet is a /24, prepending is enough to set the preferred uplink?
I am a bit worried about the capability of the RB to swallow a lot of routes in BGP, so simplifying that would be a plus. Have you got an example perhaps?
Thanks!
not sure about others, but our ISP receives only /24 ang greater networks. so you are likely can set preffered uplink per /24 subnet (or shorter mask)
an example of what? =)
The smallest subnet you can count on to be advertised properly, is a /24. So, advertising an /21 to the less preferred uplink and a /24 to the preferred, is not possible our case. So how do you manage incoming traffic? Prepending is not very reliable, I think.
An example of how you set the preference of the outgoing traffic (to the uplinks) with ‘automatic’ fallback (so, without manual interference in case the preferred uplink is down).
(We work on ios now, so I still have to learn the ROS ways)