Re: can't add a /24 blackhole route with a /32 loopback

From: Benoit Chesneau <benoitc_at_enki-multimedia.eu>
Date: Wed, 14 Jun 2023 09:06:11 UTC
I forgot oto add the error message , sorry. 

When I try to set the theblackhole flag I get the following error:

```
route: writing to routing socket: Operation not supported
change net 1.1.1.0 fib 0: Operation not supported
```


------- Original Message -------
On Wednesday, June 14th, 2023 at 10:38, Benoit Chesneau <benoitc@enki-multimedia.eu> wrote:


> Hi,
> 
> Thanks for your answer. I'm using Freebsd 13.2 latest version:
> 
> $ uname -srm
> FreeBSD 13.2-RELEASE amd64
> 
> I edited the filtred result of the table since it has a full view:
> 
> netstat -4rnW |grep -e "1.1.1"
> 1.1.1.0/24 127.0.0.1 USB 14 16384 lo0
> 1.1.1.1 link#9 UHS 26 16384 lo1
> 1.1.1.2 10.3.1.1 UGH1 15 9000 vlan2212
> 1.1.1.2 10.3.1.1 UGHS 16 1500 vlan2212
> 1.1.1.2 10.3.1.1 UGHS 25 9000 vlan2212
> 
> 
> Also I forgot to mention that the ethernet driver is MLX4EN(4):
> 
> mlx4_core0@pci0:8:0:0: class=0x028000 rev=0x00 hdr=0x00 vendor=0x15b3 device=0x1007 subvendor=0x103c subdevice=0x22f3
> vendor = 'Mellanox Technologies'
> device = 'MT27520 Family [ConnectX-3 Pro]'
> class = network
> Corrected = Advisory Non-Fatal Error
> 
> 
> 
> Hope it helps,
> 
> 
> Benoît
> ------- Original Message -------
> On Wednesday, June 14th, 2023 at 10:29, Alexander Chernikov melifaro@FreeBSD.org wrote:
> 
> 
> 
> > > On 14 Jun 2023, at 07:05, Benoit Chesneau benoitc@enki-multimedia.eu wrote:
> > > 
> > > Hi,
> > > 
> > > When I setup a loopback to a /32 , I can add a /24 as a blackhole route anymore. I can only create a /24 attached to this looopback. Ie.
> > 
> > Could you add a bit more context?
> > What is the FreeBSD version (uname -srm)?
> > What does 'route add 1.1.1.0/24 -blackhole’ show?
> > Could you also share netstat -4rnW and ifconfig output (maybe privately)?
> > 
> > > when `lo1` is set to `1.1.1.1/32` I cant create a blackhole route to `1.1.1.0/24` using the command : `route add 1.1.1.0/24 -blackhole` . Is there any reason for it? The idea is to be able to advertise the prefix `1.1.1.0/24` via BGP (bird) and use 1.1.1.1/32` as a loopback distributed to other nodes using OSPF. I can probably make the loopback a /24 used by bird but what would be the other way to do it?
> > > 
> > > Benoît