nanog mailing list archives

Re: BGP, ebgp-multihop and multiple peers


From: Iljitsch van Beijnum <iljitsch () muada com>
Date: Wed, 27 Aug 2008 09:48:01 +0200

On 27 aug 2008, at 7:58, Paul Wall wrote:

- single loopback/single IP for all peers, or;
- each peer with its own loopback/IP?

You should use caution when using loopback IP addresses and building
external multihop BGP sessions. By permitting external devices to
transmit packets to your loopback(s), you open the door to
spoof/denial of service attacks.

[...]

Indeed. I would use two loopbacks, one for internal stuff that is unreachable from the outside, another one from another range that allows the external sessions.

But that's more a question of ease of management than of risk, because if people can do something bad using one loopback address, it really doesn't matter much that additional ones are better protected.



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