BGP, ebgp-multihop and multiple peers
steve at ibctech.ca
Tue Aug 26 18:48:23 CDT 2008
This question comes after likely overlooking an IETF document or BCP
that describes what I'm after. Given that I am looking for advice from
someone who is more experienced operationally in this regard than me,
and that this technically is an implementation-neutral question, I
wanted to ask here.
Taking one router I have as an example, I have four IPv6 BGP peers (two
are for true routing, the other two for route server projects), and five
IPv4 BGP peers. Two of the v4 peers are Cymru for BOGONS, the other
three are purely outbound to route server projects. All five v4 peers
I'm looking for advice on the configuration of the peers with
I have a reserved block carved out of my allocation specifically for
/32s on loopbacks, and when I light up a new peer, I configure a new
looopback interface for that peer, and subsequently give it the next
available IP from the reserved /32 block.
There are numerous drawbacks to doing it this way... waste of IPv4
addresses, additional keystrokes on the router for interface config,
documentation, expanded margin for error et-al.
There are a few benefits to doing it this way (IMHO), but I see obvious
benefits of using a single loopback interface and single IP for ALL of
these multihop peers. Before I state good/bad, or get any wrong idea in
my head, I'd like to ask the real experts here which way they would/do
this type of thing, and why.
- single loopback/single IP for all peers, or;
- each peer with its own loopback/IP?
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