----- Original Message ----- From: "Russ White" <[email protected]> Sent: Friday, June 13, 2014 2:06 PM
<snip> > > There are two different "RIBs," at least in theory -- vendor implementations > may vary. To try and separate things out, let's describe a few tables, see > if that's a complete description, and then try to name these things. > > A - There is the set of all the reachability information received by any given > process. I would correlate this to the BGP-RIB-IN, or the LSDB in OSPF or > IS-IS. > > B - There is the set of best paths determined by the particular process. I > would correlate this to the SPT in OSPF or IS-IS, and the BGP best path > table. > > C - There is the set of paths actually installed in the local device memory, > and off of which the local forwarding tables are built. Each process running > on the device installs reachability information into this table, and there > is some arbitration method within each implementation designed to determine > which process "wins," when there are multiple installs for the same > destination, as well as "callbacks" for when routes are removed, and even > perhaps "backup routes," and the like. > > D - There is the set of forwarding table entries actually used for forwarding > traffic. Note there may be two layers of these, but they typically include > mac header rewrites, tunnel headers, and the like -- none of which any of > the "ribs" described above would contain (they would only contain a next > hop, not the actual rewrite information). > > If there are any I've missed, please feel free to add them in. This draft is > supposed to be addressing use cases that are centered on the third one above > in a "generic" way (not specific to some routing protocol, etc.). Looks comprehensive. D may vary, but I think that it is outside the remit of I2RS. It is B that I am doubtful about. It is fine for BGP or RIP, but I do not see it for link state protocols, that is for me, the SPT is not a table of routes, backup routes and so on but, well shortest paths. Do you see an IS-IS, or OSPF, table comparable to the BGP table? Tom Petch <snip> _______________________________________________ i2rs mailing list [email protected] https://www.ietf.org/mailman/listinfo/i2rs
