Re: If I announce 192.0.2.0/24, do I need a discard route? (Looking for a reference…)

> > > This sounded perfect, and I could beat my friend around the head with > it… but reading further reveals: > "Route aggregation and information reduction techniques (see > Section 9.2.2.1) may optionally be applied. > > Any local policy that results in routes being added to an Adj-RIB-Out >

Re: If I announce 192.0.2.0/24, do I need a discard route? (Looking for a reference…)

On Wed, Jan 31, 2024 at 5:56 PM, Owen DeLong wrote: > On Jan 31, 2024, at 13:46, Warren Kumari wrote: > > > > > > On Wed, Jan 31, 2024 at 3:56 PM, William Herrin wrote: > >> On Wed, Jan 31, 2024 at 12:30 PM Warren Kumari >> wrote: >> >> So, let's say I'm announcing some address space (e.g

Re: If I announce 192.0.2.0/24, do I need a discard route? (Looking for a reference…)

> On Jan 31, 2024, at 13:46, Warren Kumari wrote: > > > > > > On Wed, Jan 31, 2024 at 3:56 PM, William Herrin > wrote: >> On Wed, Jan 31, 2024 at 12:30 PM Warren Kumari > > wrote: >> >> So, let's say I'm announcing some address space (e.g

Re: If I announce 192.0.2.0/24, do I need a discard route? (Looking for a reference…)

On Wed, Jan 31, 2024 at 5:20 PM, Tom Beecher wrote: > It that always true? I'd started off thinking that, but a friend of mine >> (yes, the same one that started this argument) convinced me that >> some forms of BGP summarization/aggregation don't always generate a "local" >> route… >> >> I'd

Re: If I announce 192.0.2.0/24, do I need a discard route? (Looking for a reference…)

> > It that always true? I'd started off thinking that, but a friend of mine > (yes, the same one that started this argument) convinced me that > some forms of BGP summarization/aggregation don't always generate a "local" > route… > > I'd also thought that I'd seen this when redistributing an IGP

Re: If I announce 192.0.2.0/24, do I need a discard route? (Looking for a reference…)

On Wed, Jan 31, 2024 at 1:46 PM Warren Kumari wrote: > On Wed, Jan 31, 2024 at 3:56 PM, William Herrin wrote: >> On Wed, Jan 31, 2024 at 12:30 PM Warren Kumari wrote: >> Your router won't announce 192.0.2.0/24 unless it knows a route to >> 192.0.2.0/24 or has been configured to aggregate any

Re: If I announce 192.0.2.0/24, do I need a discard route? (Looking for a reference…)

On Wed, Jan 31, 2024 at 3:56 PM, William Herrin wrote: > On Wed, Jan 31, 2024 at 12:30 PM Warren Kumari wrote: > > So, let's say I'm announcing some address space (e.g 192.0.2.0/24), but > I'm only using part of it internally (e.g 192.0.2.0/25). I've always > understood that it's best

Re: If I announce 192.0.2.0/24, do I need a discard route? (Looking for a reference…)

Hello Warren, Speaking from my experience here. You've understood correctly. You need to create a null/blackhole route within your routing table (static routes work best as it guarantees the route exists) in order to announce the /24 supernet if you're using longer subnets (/25 to /32). The

Re: If I announce 192.0.2.0/24, do I need a discard route? (Looking for a reference…)

On Wed, Jan 31, 2024 at 12:30 PM Warren Kumari wrote: > So, let's say I'm announcing some address space (e.g 192.0.2.0/24), > but I'm only using part of it internally (e.g 192.0.2.0/25). I've always > understood that it's best practice[0] to have a discard route (eg static > to null0/discard or

Re: If I announce 192.0.2.0/24, do I need a discard route? (Looking for a reference…)

> On Jan 31, 2024, at 12:30, Warren Kumari wrote: > > Hey all, > > This falls into the "Somebody is wrong on the Internet …" category. Doesn’t everything eventually end up there? > So, let's say I'm announcing some address space (e.g 192.0.2.0/24 > ), but I'm only