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 10:18:37 UTC

------- Original Message -------
On Wednesday, June 14th, 2023 at 11:56, Alexander Chernikov <melifaro@FreeBSD.org> wrote:

> Could you try:
> 1) removing the 1.1.1.0/24 route
> 2) removing the 1.1.1.1/32 from the lo1
> 3) provide the output for `route -n get 1.1.1.0/24`
> 4) provide the output for `route -n get 1.1.1.1/32`
> 5) assign 1.1.1.1/32 to lo1
> 6) provide the output for `route -n get 1.1.1.0/24`
> 7) provide the output for `route -n get 1.1.1.1/32`
> 8) provide the output for `route add -net 1.1.1.0/24 -blackhole`
> 

Find the result below. Such thing worked on another machine, I am not sure why. No obvious logs.

```
# route -n get 1.1.1.0/24
   route to: 1.1.1.0
destination: 1.1.1.0
       mask: 255.255.255.0
        fib: 0
  interface: lo1
      flags: <UP,DONE,STATIC>
 recvpipe  sendpipe  ssthresh  rtt,msec    mtu        weight    expire
       0         0         0         0     16384         1         0
# route -n get 1.1.1.1/32
   route to: 1.1.1.1
destination: 1.1.1.1
    gateway: 10.3.1.2
        fib: 0
  interface: vlan212
      flags: <UP,GATEWAY,HOST,DONE,PROTO1>
 recvpipe  sendpipe  ssthresh  rtt,msec    mtu        weight    expire
       0         0         0         0      9000         1         0
# route delete 1.1.1.0/24
delete net 1.1.1.0
# route -n get 1.1.1.1/32
route: route has not been found
# ifconfig lo1 inet 1.1.1.1/32
# route -n get 1.1.1.1/32
   route to: 1.1.1.1
destination: 1.1.1.1
        fib: 0
  interface: lo1
      flags: <UP,HOST,DONE,PINNED>
 recvpipe  sendpipe  ssthresh  rtt,msec    mtu        weight    expire
       0         0         0         0     16384         1         0
# route add -net 1.1.1.0/24 -blackhole
route: writing to routing socket: Operation not supported
add net 1.1.1.0 fib 0: Operation not supported
# route -n get 1.1.1.0/24
route: route has not been found
```