ifconfig lo1 down

[fredrik danerklint]

söndagen den 6 mars 2011 21.29.30 skrev  Bjoern A. Zeeb:
> On Sun, 6 Mar 2011, fredrik danerklint wrote:
> 
> Hi,
> 
> > lördagen den 5 mars 2011 21.10.19 skrev  Sergey Kandaurov:
> >> On 5 March 2011 21:43, fredrik danerklint <fredan at fredan.se> wrote:
> >>> Hi,
> >>> 
> >>> I would like to know what is the differents between ip4 and ip6 for
> >>> this command.
> >>> 
> >>> First:
> >>> 
> >>> #ifconfig lo1
> >>> lo1: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
> >>> 
> >>>        options=3<RXCSUM,TXCSUM>
> >>>        inet xx.xx.xx.2 netmask 0xffffffff
> >>>        inet6 2a03:xxxx:xxxx::xxxx:xx02 prefixlen 128
> >>>        nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
> >>> 
> >>> $ ping xx.xx.xx.2
> >>> PING xx.xx.xx.2 (xx.xx.xx.2): 56 data bytes
> >>> 64 bytes from xx.xx.xx.2: icmp_seq=0 ttl=64 time=0.012 ms
> >>> 64 bytes from xx.xx.xx.2: icmp_seq=1 ttl=64 time=0.010 ms
> >>> ^C
> >>> 
> >>> and
> >>> 
> >>> $ ping6 2a03:xxxx:xxxx::xxxx:xx02
> >>> PING6(56=40+8+8 bytes) 2a03:xxxx:xxxx::xxxx:xx02 -->
> >>> 2a03:xxxx:xxxx::xxxx:xx02 16 bytes from 2a03:xxxx:xxxx::xxxx:xx02,
> >>> icmp_seq=0 hlim=64 time=0.053 ms 16 bytes from
> >>> 2a03:xxxx:xxxx::xxxx:xx02, icmp_seq=1 hlim=64 time=0.032 ms ^C
> >>> 
> >>> Now we run this command:
> >>> 
> >>> # ifconfig lo1 down
> >>> 
> >>> and trying to ping again:
> >>> 
> >>> $ ping xx.xx.xx.2
> >>> PING xx.xx.xx.2 (xx.xx.xx.2): 56 data bytes
> >>> ping: sendto: No route to host
> >>> ping: sendto: No route to host
> >>> ping: sendto: No route to host
> >>> ^C
> >>> --- xx.xx.xx.2 ping statistics ---
> >>> 3 packets transmitted, 0 packets received, 100.0% packet loss
> >>> 
> >>> works as expected (and this is what I want) but this command, however:
> >>> 
> >>> $ ping6 2a03:xxxx:xxxx::xxxx:xx02
> >>> PING6(56=40+8+8 bytes) 2a03:xxxx:xxxx::xxxx:xx02 -->
> >>> 2a03:xxxx:xxxx::xxxx:xx02 16 bytes from 2a03:xxxx:xxxx::xxxx:xx02,
> >>> icmp_seq=0 hlim=64 time=0.048 ms 16 bytes from
> >>> 2a03:xxxx:xxxx::xxxx:xx02, icmp_seq=1 hlim=64 time=0.033 ms 16 bytes
> >>> from 2a03:xxxx:xxxx::xxxx:xx02, icmp_seq=2 hlim=64 time=0.032 ms ^C
> >>> --- 2a03:xxxx:xxxx::xxxx:xx02 ping6 statistics ---
> >>> 3 packets transmitted, 3 packets received, 0.0% packet loss
> >>> round-trip min/avg/max/std-dev = 0.032/0.038/0.048/0.007 ms
> >>> 
> >>> My question is why is it not the same behavior of ip6 as of ip4?
> >> 
> >> That's how forwarding works/differs for ipv4 and ipv6.
> >> You should be able to ping xx.xx.xx.2 again after adding static route.
> >> Something like route add xx.xx.xx.2 -iface -lo1.
> >> 
> >> 
> >> I can only say for the moment that from my observation ipv4 "routes to
> >> itself" exist as far as interface is up, and ipv6 routes don't depend on
> >> if iface is up. You can check this with netstat -r for both addresses
> >> with iface up and down.
> > 
> > Hmm... take a look at this:
> > 
> > Internet:
> > Destination        Gateway            Flags    Refs      Use  Netif
> > Expire xx.xx.xx.2        link#8             UH          0        0   
> > lo1
> > 
> > Internet6:
> > Destination                       Gateway                       Flags
> > Netif Expire
> > 2a03:xxxx:xxxx::xxxx:xx02          link#8                        UHS
> > lo0
> > 
> > See the differents? For ip4 it uses the correct interface, lo1, but on
> > ip6 it uses the lo0 interface and sure enough it is not down at all.
> 
> It's new-arp fallout and related to the carp problems with IPv6.

ok. where can I read about this problem with carp (since that is what I also 
gonna to use later on with ip6..)

Is there any kind of information about the status of ip6 in FreeBSD. I mean 
really a list of what works and what not works? 

-- 
//fredan