Re: [External] Re: uPRF strict more

2021-10-01 Thread Mark Tinka
On 10/1/21 19:28, Randy Bush wrote: in fact, this seems to be the modern conservative style for some years. i sometimes wonder if it is worth the config pain. If having routers dedicated to peering, transit or edge functions is worth the extra pain, in lieu of doing it all on one box?

Re: [External] Re: uPRF strict more

2021-10-01 Thread Mark Tinka
On 10/1/21 20:17, Adam Thompson wrote: Do people in other parts of the world have access (both physical and logical) to enough bilateral peering (and budgets...) that it makes sense to deploy a router per peer? Certainly not a router per peer, but a peering router per city, where it may

Re: [External] Re: uPRF strict more

2021-10-01 Thread Saku Ytti
──┘ > > > Adam Thompson > Consultant, Infrastructure Services > > 100 - 135 Innovation Drive > Winnipeg, MB, R3T 6A8 > (204) 977-6824 or 1-800-430-6404 (MB only) > athomp...@merlin.mb.ca > www.merlin.mb.ca > > From: NANOG on behalf of &g

Re: [External] Re: uPRF strict more

2021-10-01 Thread Adam Thompson
merlin.mb.ca/> From: NANOG on behalf of Randy Bush Sent: October 1, 2021 12:28 To: Mark Tinka Cc: North American Network Operators' Group Subject: Re: [External] Re: uPRF strict more > A partial table with no default is perfectly fine for a peering ro

Re: [External] Re: uPRF strict more

2021-10-01 Thread Randy Bush
> A partial table with no default is perfectly fine for a peering router. > > As long as your peering router knows how to get to your prefixes and > those of your customers, as well as the prefixes of the networks you > peer with, you're good to go. in fact, this seems to be the modern

Re: [External] Re: uPRF strict more

2021-09-30 Thread Mark Tinka
On 10/1/21 01:51, Valdis Klētnieks wrote: Am I insufficently caffienated, or is uRPF the least of your problems if you don't have a full table *and* don't have a default route? A partial table with no default is perfectly fine for a peering router. As long as your peering router knows how

Re: [External] Re: uPRF strict more

2021-09-30 Thread Valdis Klētnieks
On Thu, 30 Sep 2021 18:12:51 +0200, Mark Tinka said: > I should have said "If you don't plan to run a full BGP table on a > device without a default a route as well, Am I insufficently caffienated, or is uRPF the least of your problems if you don't have a full table *and* don't have a default

Re: [External] Re: uPRF strict more

2021-09-30 Thread Sabri Berisha
- On Sep 30, 2021, at 9:13 AM, Andrew Smith andrew.william.sm...@gmail.com wrote: Hi, > In Ciscoland, you do have to explicitly state that the default route is > eligible > for URPF verification, otherwise you'll get unexpected traffic drops. > ip verify unicast source reachable-via any

RE: [External] Re: uPRF strict more

2021-09-30 Thread Brian Turnbow via NANOG
Hi > > > What it does allow is for *deliberate* blackholing for traffic; if you > > null-route a prefix, you now block incoming traffic from that subnet > > as well. This can be useful and it is how we are using URPF. > > I don't think it is implied here, but just for clarification this is >

Re: [External] Re: uPRF strict more

2021-09-30 Thread Saku Ytti
On Thu, 30 Sept 2021 at 19:00, Hunter Fuller via NANOG wrote: > What it does allow is for *deliberate* blackholing for traffic; if you > null-route a prefix, you now block incoming traffic from that subnet > as well. This can be useful and it is how we are using URPF. I don't think it is

Re: [External] Re: uPRF strict more

2021-09-30 Thread Andrew Smith
In Ciscoland, you do have to explicitly state that the default route is eligible for URPF verification, otherwise you'll get unexpected traffic drops. ip verify unicast source reachable-via any allow-default And yes, it's main purpose is for implementing source-based remotely-triggered

Re: [External] Re: uPRF strict more

2021-09-30 Thread Mark Tinka
On 9/30/21 17:56, Hunter Fuller wrote: On Thu, Sep 30, 2021 at 12:08 AM Mark Tinka wrote: If you don't plan to run a full BGP table on a device, don't enable uRPF, even loose-mode. At least in Ciscoland, loose URPF checks will pass if you have a default route. So I do not think it could

Re: [External] Re: uPRF strict more

2021-09-30 Thread Hunter Fuller via NANOG
On Thu, Sep 30, 2021 at 12:08 AM Mark Tinka wrote: > If you don't plan to run a full BGP table on a device, don't enable uRPF, > even loose-mode. At least in Ciscoland, loose URPF checks will pass if you have a default route. So I do not think it could result in inadvertent blackholing of