I have an application that needs to gather BGP RIB data from the routers
that connect to all of our upstream providers. Basically I need to know
all the routes available from a particular provider. Currently I'm
gathering this data via SNMP. While this works it has its draw backs, it
takes approximately 20 minutes per view, its nowhere near real-time, and
I'm unable to gather information for IPv6. SNMP, however, is faster than
screen scraping. All of the XML based access methods seem to take about
the same time as well.
I've been watching, with keen interest, the i2rs ietf workings, but the
project is still in its infancy. BMP seems to be a good solution but I've
not found a working client implementation yet. I see that you can actually
configure this on some Juniper gear but I can't seem to locate a client to
ingest the data the router produces. The BGP Add Paths implementation
seems to be the best choice at the moment and exabgp has a working
implementation.
Are there any other technologies or methods of accessing this data that
I've missed or that you've found useful?
Personally, I would just use BGP on a PC to collect this information.
Place some import/input policy on your eBGP sessions on your edge
routers to add communities to the routes such that you can recognize
which peers gave you the route.
Then, use an iBGP session to a BIRD or Quagga instance from which you
can dump the routes and filter based on the communities.
whoa, you must really hate your router to do that to it.
While this works it has its draw backs, it
takes approximately 20 minutes per view, its nowhere near real-time, and
I'm unable to gather information for IPv6. SNMP, however, is faster than
screen scraping. All of the XML based access methods seem to take about
the same time as well.
I'll chime in with what we are doing with quagga and bgpmon.
The question though would be for how many peers? If it is
for the sake of discussion, less than 20, something like this
might work.
We do some of this. The pure BGPmon way is to have neighbors
peer directly with a BGPmon server. We've extended this a bit
and we can stream quagga MRT update files into a bgpmon server as well.
Then the BGPmon server internally constructs RIBs per session.
Output format is XML, and the paper linked above describes some of
the perl tools there are to look at xml streams.
So you can get a RIB stream or an UPDATE stream from the
BGPmon server. At some scale, this might give you what you need.
I think the BMP solution looks pretty nice as well, since you
are as close to your true platform as you can get. So I would
also be interested in hearing if you find existing client code
to parse the BMP.
*received-routes*?
If you still enable soft-reconfig-inbound on your routers(customer-facing sessions not withstanding), you most certainly hate your routers more than OP...
./Randy
*received-routes*?
If you still enable soft-reconfig-inbound on your routers(customer-facing sessions not withstanding), you most certainly hate your routers more than OP...
it impacts memory, but if your management plane has enough memory to handle
it, it's a useful debugging tool. For sure, it's the first thing I throw
out if the management plane RAM runs short.
SNMP polling of large router lists can work out as O(n^2) CPU usage if the
router stores the polled objects as linked lists or in some cases, in tree
structures. This is because snmpgetnext cannot maintain a pointer to the
next object, which in some situations will mean a complete tree walk
operation. So your CPU requirements will scale according to (size of
structure) * (average number of complete walks through the structure). If
you're using linked lists, or have a naive tree implementation, "average
number of complete walks through the structure" = "size of structure" / 2
for a full tree walk. I.e. you can require (n^2)/2 complete runs through
the structure in order to run a full snmp dump. Obviously this isn't
always the case, but there are some well known examples of where it happens.
For all its faults, soft-reconfig-inbound only adds O(N) to RAM
requirements and almost nothing to CPU.
I have an application that needs to gather BGP RIB data from the routers
that connect to all of our upstream providers. Basically I need to know
all the routes available from a particular provider. Currently I'm
gathering this data via SNMP. While this works it has its draw backs, it
takes approximately 20 minutes per view, its nowhere near real-time, and
I'm unable to gather information for IPv6. SNMP, however, is faster than
screen scraping. All of the XML based access methods seem to take about
the same time as well.
I've been watching, with keen interest, the i2rs ietf workings, but the
project is still in its infancy. BMP seems to be a good solution but I've
not found a working client implementation yet. I see that you can actually
configure this on some Juniper gear but I can't seem to locate a client to
ingest the data the router produces.
