BGP terminology question

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1

NetSecGuy wrote:

I understand AS3333 is RIS itself, is this some kind of misconfig on their
end? It seems to be announcing it's entire table every 5 minutes. This
started late Friday and ended a few hours ago.

FYI, AS3333 is the RIPE NCC's production AS; the RIS project uses AS12654.

There seems to be a difference between the behaviours of Cisco and Juniper
routers when encountering the RIS's default keepalive value of 0. Cisco
routers (and Zebra/Quagga boxes) seem to operate quite happily without
keepalive processing while Junipers seem to tear down and restart the session
after the holdtime expires -- result: 170,000 or so additional updates every
holdtime-and-a-bit seconds. [Aside: shouldn't the session be refused at
startup if a mutually agreeable keepalive value can't be negotiated rather
than being allowed to flap like this?]

This problem seems to occur when any RIS peer migrates from Cisco to Juniper.
The only difference this time is that both ASes are operated by (different
groups within) the RIPE NCC.

James

2

Junipers seem to be slightly in the wrong here. A hold time of zero is
acceptable, though unwise, IMHO. In this case no keepalives are sent,
and the systems have to rely on other means (such as the TCP connection)
to ensure they're both alive, but one could easily imagine a situation
where the TCP connection remains intact after the BGP process has gone
to lunch. Not good.

In any case, the systems are required to agree on the lowest of the two
proposed hold times, except to note that hold times of 1 or 2 seconds
are not allowed. Hence, the Junipers should accept and use the proposed
hold time of 0.

  -- Per