uPRF strict more

Wed Sep 29 11:54:00 UTC 2021

On 9/29/21 02:47, Randy Bush wrote:

> do folk use uPRF strict mode?  i always worried about the multi-homed
> customer sending packets out the other way which loop back to me;  see
> RFC 8704 §2.2

We do loose-mode for BGP customers, regardless of whether they are 
single- or multi-homed.

We do loose-mode on transit routers, as they hold a full table.

We do strict-mode for stub DIA customers.

We do loose-mode for multi-homed DIA customers.

We don't do uRPF on peering routers, as they don't hold a full table.

> do vendors implement the complexity of 8704; and, if so, do operators
> use it?

Juniper support Feasible Paths, and we use it with no issue.

We don't use Cisco in this role anymore, so not sure.

Mark.