> On Jun 22, 2016, at 23:17 , Mark Tinka <mark.ti...@seacom.mu> wrote: > > > > On 23/Jun/16 08:07, Owen DeLong wrote: > >> If it’s 100% for redundancy, why not just ECMP defaults and not take a full >> table? > > Well, firstly, ring length may be different on either end. So you can't > always guarantee ECMP of traffic to/from the device (without much > difficulty such as MPLS-TE).
Unless the difference is HUGE, you usually don’t really care. > You also can't do hop-by-hop routing based on 0/0 or ::/0 when the ring > contains multiple devices also doing the same thing. You'll just create > a loop. MPLS-based forwarding is your friend here. Who said anything about a ring. He is advertising a /24 to 2 upstream providers. Likely these are two separate transit circuits. > But yes, if your device is not in a ring, then your suggestion is fine. Even if you’re in a ring if you’ve got two transit providers at some random point on the ring, it still probably doesn’t make a meaningful difference between full feeds from each vs. ECMP, because it’s pretty unlikely that the AS PATH length is affected by the ring length. Owen
