Hi all
When we get newip, we should let the upstream know to expor it as
there should have rule in their side.
how about upstream provider, does they need to let their all bgp
interconnect to know those our newip?
If no, Can I know how it works?
If they don't have rules each other, ls it any problems?
Thank you so much
It depends on your upstream ISPs.
Conventionally, some choose to place exact filters in place on BGP
announcements that exactly match IP space that is registered with a RIR or
LIR, some build those filters from IRR sources, and others just filter on
the number of prefixes your sending (to avoid sending a whole table out on
accident). I'm sure there are some other filtering schemes in place around
the world.
In the case of exact filters, you'll need to contact your upstream ISPs and
ask them to update their filters.
In the case of IRR-sourced filtering information, update the prefixes that
you originate with your IRR provider.
And in the case of max-prefix filtering, ask your ISP what they have their
equipment set to.
Cheers,
jof
When we get newip, we should let the upstream know to expor it as
there should have rule in their side.
Correct. Ideally, two things happen:
1. You tell your upstreams and peers about the new space, and they update whatever prefix filters they have in place for your network.
2. You update you own outbound BGP filters wherever necessary so that you can announce the new prefix, aggregated to the extent possible, when you're ready.
how about upstream provider, does they need to let their all bgp
interconnect to know those our newip?
They might. It depends on the relationship your upstreams have with their neighbors. Different providers have different criteria for what they'll accept and how they manage their filters.
If your upstreams need to have their upstreams and/or peers update their BGP filters, it is their responsibility to notify them. Note that this can add to the amount of time it will take before your direct upstreams are ready to accept and propagate your new prefix.
Some providers might require that your new prefix be registered in one of several routing registries, and they'll update their filters based on your new registry data.
jms
Hi Justin
Thank you
Could you tell me more about "routing registries"?
I would like to learn it
2nd questions? Are you familiar to quagga?
ls it supporting equally multipath in different bgp connections?
Thank you so much
Could you tell me more about "routing registries"?
I would like to learn it
google it, and RADB for example.
2nd questions? Are you familiar to quagga?
ls it supporting equally multipath in different bgp connections?
Yes, absolutely.
Could you tell me more about "routing registries"?
I would like to learn it
In a nutshell, Internet Routing Registries (IRRs) are places where networks can store information that describes their routing policies. Other networks can query this information and use the results to build or update their filtering policies. You can find an extensive list of registries and more background information at http://www.irr.net/
2nd questions? Are you familiar to quagga?
ls it supporting equally multipath in different bgp connections?
I haven't messed around too much with quagga, so I can't give you a good answer on that at the moment.
jms
Most software routing protocols have support for this in their RIBs,
but the actual forwarding ability of the underlying kernel will
determine the support for this.
What platform do you route on?
Cheers,
jof
Hi
Thank you all of you
Can I have one question?
We are planning to have 3 x 1G bgp connections (full tables) eg: Path A, B, C
Can I say that we have 3G output totally?
From my understanding, the bgp chooses the best path to route automatically
If the path A is best route and that path 1G bandwidth is used up,
will bgp try to use path B and path C automatically?
or the bgp still choose to path A whatever the bandwidth is used up
How can I use up those 3G?
Thank you so much
PS: my platform is linu
We are planning to have 3 x 1G bgp connections (full tables) eg: Path A, B, C
Can I say that we have 3G output totally?
Sure.
From my understanding, the bgp chooses the best path to route automatically
It doesn't. It typically chooses the path with the least number of
autonomous systems for a given destination. That can actually result
in longer physical paths in many cases.
Let's say provider C buys bandwidth from A and B (and nobody else).
If that's the case, you will only use C for things directly connected
to C's network (typically only things that pay C), but every other
internet destination would use A or B. (unless you adjust things to
not do this).
If the path A is best route and that path 1G bandwidth is used up,
will bgp try to use path B and path C automatically?
No, with one caveat. If you fill up the pipe enough that routing
messages don't get through, those routes will eventually time out and
the path won't be used at all.
How can I use up those 3G?
You will need to manually adjust routes, preferences, etc. You'll
still have one path that is hotter than the others (although hopefully
not too much hotter).
Are you worried about incoming or outgoing bandwidth, or both? For
incoming, you will need to do things like:
1) Announce all of your prefixes aggregated out all 3 links
2) Announce parts of your prefixes out ONLY ONE link. So announce /24
#1 out A, /24 #2 out B, /24 #3 out C. This means you're forcing
incoming traffic to generally come in one link per /24. The problem
with this is that a really active /24 will get more traffic still. It
also requires you to have at least 3 /24s (you can't route longer
prefixes, which means you can't route PART of a /24).
For outbound, the easy and obvious way would be for your providers to
just announce 0/0 to you and for you to do some sort of flow-based
load balancing. But if one provider had reachability problems, you'd
go down. So without that, you'll have to adjust the preferences of
incoming routes.
Alternatively use BGP multipath and buy from one provider (and connect
to the same router on the provider side). Bandwidth from one provider
isn't necessarily a horrible thing, if you pick a good one provider.
Even with multiple BGP feeds, unless you are really, really careful
(and, most likely, spend tons of money for things like fiber
redundancy so the different fibers don't all end up on one pole or
going into the same telco building) you'll still have single points of
failure.