A basic question : routes TTL ?

I'm using the term TTL because it's the way I'm guessing it works.
But precisely I do not know.

Here is the case :

On an OpenBSD box, one NIC (em1) is configured in hostname.em1 to get :

- 2 public IP's with a /28 netmask, from a reserved public range

- 4 more aliases with a /32 netmask, from the same public range (I heard this could be to make them look used)

I wanted to use one of the "aliased" IP's so I deleted it from this 'hostname.em1' file, and restarted the network (sh /etc/netstart on BSD).

I realised that it didn't change anything from outside, I would still ping it with a response.

So, I went 'ifconfig em1', and could see that, indeed, the aformentioned 'aliased' IP I had deleted from 'hostname.em1' was still configured.
I deleted it (ifconfig em1 delete XX.XX.XX.XX), and it disappeared, and I could not reach this server anymore with this IP.

Ok, thats all good until there.

Now, my question is here :

Why, after deleting the entry manually with ifconfig, a 'route show' will still list the deleted IP as routing to localhost ?

(The question could also apply to 'why executing 'sh /etc/netstart' did not remove the address from ifconfig ?', but it's not the main topic for me).

Getting back to my title, again, I'm guessing there is some kind of TTL ? Or a deamon will update this soon (ripd maybe ?) ?
Thanks for your inputs.