Default route (IPv4) demolished by destroying clone (gif/gre) interface

[Dmitry Pryanishnikov]

Hello!

On Wed, 16 Aug 2006, Yar Tikhiy wrote:
> The question is:  Do all the routes really need to be flushed upon
> the destruction of an interface?

  I've killed devd on my test machine (yesterday's RELENG_6) and done
the following:

root at test# ifconfig vlan0 create
root at test# ifconfig vlan0 inet 10.1.1.1/30
root at test# route add 10.2.2.0/24 10.1.1.1
add net 10.2.2.0: gateway 10.1.1.1
root at test# nst -rn
Routing tables
Internet:
Destination        Gateway            Flags    Refs      Use  Netif Expire
default            193.108.47.145     UGS         0    64439    rl0
10.0.0.252/30      link#1             UC          0        0   fxp0
10.1.1/30          link#4             UC          0        0  vlan0
10.1.1.1           00:00:00:00:00:00  UHLW        2        0    lo0
10.2.2/24          10.1.1.1           UGS         0        0  vlan0
127.0.0.1          127.0.0.1          UH          0        0    lo0
193.108.47.144/29  link#2             UC          0        0    rl0
193.108.47.145     00:02:b3:8b:26:4a  UHLW        2    20523    rl0     38
root at test# ifconfig vlan0 destroy
root at test# nst -rn
Routing tables
Internet:
Destination        Gateway            Flags    Refs      Use  Netif Expire
default            193.108.47.145     UGS         0    64500    rl0
10.0.0.252/30      link#1             UC          0        0   fxp0
127.0.0.1          127.0.0.1          UH          0        0    lo0
193.108.47.144/29  link#2             UC          0        0    rl0
193.108.47.145     00:02:b3:8b:26:4a  UHLW        2    20571    rl0     58

So it seems that just simple 'ifconfig vlan0 destroy' already takes care
about all the routes via the defunct interface, and does this correctly.
The question is whether interface auto-destruction code in kernel does
the same. I don't have removable NIC hardware handy to check this.

Sincerely, Dmitry
-- 
Atlantis ISP, System Administrator
e-mail:  dmitry at atlantis.dp.ua
nic-hdl: LYNX-RIPE