Add/Delete IPv6 addresses and netlink

Add/Delete IPv6 addresses and netlink

[Ben Greear]

I am not sure this is a bug, but it is at least making my life difficult 
in user-space.

This is with 2.6.25.4 kernel plus some of my own hackings not directly 
related
to ipv6.

First:
You can get a state where you never get a netlink address add message, but
you do get the delete message.  Eth0 has no link, by the way, but it 
does not
seem to matter in this particular case:

ip -6 addr flush eth0
ip link set dev eth0 down
ip -6 addr add 2000::8:2/112 scope global dev eth0
ip -6 addr flush eth0

I would much prefer to have a netlink message when the address is added, 
regardless of
whether it is tentative or not.  A new message could be sent when it 
changes state to/from tentative.
As it is, there is no way to verify that an IP address was actually 
added by listening to netlink
messages if the address stays tentative.

Second:

NOTE:  I cannot reproduce this problem on FC8's 2.6.24.7-92.fc8 kernel 
on a different
machine.  It may just be something lame about my development 
environment, the different
hardware, or perhaps some issue with the newer lkml kernel.

I am not sure whether I am just confused about how all of this is 
supposed to work or not, but the
following commands will leave the global address in tentative state:

ip link set eth1 down; ip -6 addr flush dev eth1;
ip -6 addr add 2000::9:2/112 scope global dev eth1
ip link set eth1 up
# Wait 10+ seconds
ip -6 addr show dev eth1
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
    inet6 2000::9:2/112 scope global tentative
       valid_lft forever preferred_lft forever
    inet6 fe80::203:2dff:fe0c:d022/64 scope link
       valid_lft forever preferred_lft forever

If you add the global addr while the device is already up, however, then 
it will not be in
tentative state.

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com> 
Candela Technologies Inc  http://www.candelatech.com

Re: Add/Delete IPv6 addresses and netlink

[Thomas Graf]

* Ben Greear <greearb@candelatech.com> 2008-06-16 18:33
> I am not sure whether I am just confused about how all of this is 
> supposed to work or not, but the
> following commands will leave the global address in tentative state:
> 
> ip link set eth1 down; ip -6 addr flush dev eth1;
> ip -6 addr add 2000::9:2/112 scope global dev eth1
> ip link set eth1 up
> # Wait 10+ seconds
> ip -6 addr show dev eth1
> 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
>    inet6 2000::9:2/112 scope global tentative
>       valid_lft forever preferred_lft forever
>    inet6 fe80::203:2dff:fe0c:d022/64 scope link
>       valid_lft forever preferred_lft forever

Do you see a "ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready"
message in the console when you up the device?

Re: Add/Delete IPv6 addresses and netlink

[Ben Greear]

Thomas Graf wrote:
> * Ben Greear <greearb@candelatech.com> 2008-06-16 18:33
>   
>> I am not sure whether I am just confused about how all of this is 
>> supposed to work or not, but the
>> following commands will leave the global address in tentative state:
>>
>> ip link set eth1 down; ip -6 addr flush dev eth1;
>> ip -6 addr add 2000::9:2/112 scope global dev eth1
>> ip link set eth1 up
>> # Wait 10+ seconds
>> ip -6 addr show dev eth1
>> 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
>>    inet6 2000::9:2/112 scope global tentative
>>       valid_lft forever preferred_lft forever
>>    inet6 fe80::203:2dff:fe0c:d022/64 scope link
>>       valid_lft forever preferred_lft forever
>>     
>
> Do you see a "ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready"
> message in the console when you up the device?
>   

No, I do not see this message.   I do see a driver message in the kernel:

Jun 17 08:43:04 localhost kernel: eth1: link up, 100Mbps, full-duplex, 
lpa 0x41E1

I'm using the 8139too driver.  I notice that it shows full link
speed (100-FD) when the NIC is admin down.   Maybe that is causing it to not
go through an expected state change?

I'll work on doing this same test with a vanilla kernel but on this 
hardware just in case I've
screwed something up somewhere...

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com> 
Candela Technologies Inc  http://www.candelatech.com

Re: Add/Delete IPv6 addresses and netlink

[Ben Greear]

Ben Greear wrote:
>
> I'm using the 8139too driver.  I notice that it shows full link
> speed (100-FD) when the NIC is admin down.   Maybe that is causing it 
> to not
> go through an expected state change?
>
> I'll work on doing this same test with a vanilla kernel but on this 
> hardware just in case I've
> screwed something up somewhere...
I just re-did this test on the latest FC8 kernel and the same problem 
appears.

ip link set eth1 down; ip -6 addr flush dev eth1;
Nothing to flush.
ip -6 addr add 2000::9:2/112 scope global dev eth1
ip link set eth1 up
ip -6 addr show dev eth1
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
    inet6 2000::9:2/112 scope global tentative
       valid_lft forever preferred_lft forever
    inet6 fe80::203:2dff:fe04:65b1/64 scope link
       valid_lft forever preferred_lft forever
uname -a
Linux lanforge-65-AF 2.6.25.4-10.fc8 #1 SMP Thu May 22 23:34:09 EDT 2008 
i686 i686 i386 GNU/Linux

I wonder if it's something to do with the 8139too driver.  Can anyone 
else with that NIC
confirm?

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com> 
Candela Technologies Inc  http://www.candelatech.com