On Feb 3, 2012, at 3:10 PM, -Hammer- wrote: > So, we are preparing to add IPv6 to our multi-homed (separate routers and > carriers with IBGP) multi-site business. Starting off with a lab of course. > Circuits and hardware are a few months away. I'm doing the initial designs > and having some delivery questions with the carrier(s). One interesting > question came up. There was a thread I found (and have since lost) regarding > what routes to accept. Currently, in IPv4, we accept a default route only > from both carriers at both sites. Works fine. Optimal? No. Significantly > negative impact? No. In IPv6, I have heard some folks say that in a > multi-homed environment it is better to get the full IPv6 table fed into both > of your edge routers. Ok. Fine. Then, The thread I was referring to said that > it is also advisable to have the entire IPv4 table fed in parallel. Ok. I > understand we are talking about completely separate protocols. So it's not a > layer 3 issue. The reasoning was that DNS could potentially introduce some > latency. > > "If you have a specific route to a AAAA record but a less specific route to > an A record the potential is for the trip to take longer." > > That was the premise of the thread. I swear I googled it for 20 minutes to > link before giving up. Anyway, can anyone who's been thru this provide any > opinions on why or why not it is important to accept the full IPv6 table AND > the full IPv4 table? I have the hardware to handle it I'm just not sure long > term what the reasoning would be for or against. Again, I'm an end customer. > Not a carrier. So my concern is (A) my Internet facing applications and (B) > my users who eventually will surf IPv6. > > Any guidance would be appreciated. Thanks. > > -Hammer-
We have been accepting our upstreams' connected and customer routes only (v4) and full routes (v6) without issue. I can't say that I have previously heard of the DNS performance example/concern you provided above
