[cgl_discussion] IPv6 MIBs/SNMP requirements/support

[Venkata Jagana]

Hello Zou,

Thanks for your findings on net-snmp support for these MIBs :)
Based on your findings, it looks like there are still some
IPv6 MIB objects missing but this support needs to be provided.

In addition,  the ioctl interface support (item 3, as outlined in
my original mail) needs to be provided for most of these objects as
you have identified. Would you go ahead and then start implementing
this 'ioctl support for the kernel' along with MIB objects (item 2)
for net-snmp project since Randy is focussing on kernel implementation
of the various statistics parameters (item 1 in my original mail).

See some additional comments below.

>> 2) SNMP Agent must also provide the support of these IPv6 MIB's.
>> It further means that it must support corresponding encoding of
>> these various object groups and obtain the data from the kernel.
>>
>>  The net-snmp project (www.netsnmp.org) claims to have this support
>> provided already in their released versions but this code needs to
>> be validated for Linux to understand their current level of
>> support.
>>

>Ok, I just looked into the source code for the NET-SNMP release 5.0.7.
>Here's my findings regarding to the support of IPv6.

>IPV6-MIB::ipv6IfTable
>    This is the only table I was able to verify on my redhat 8.0 box.
>    Largely implemented. Except the following OIDs:
>              ipv6IfReasmMaxSize:          not done
>              ipv6IfIdentifier:            not done
>              ipv6IfIdentifierLength:      not done
>              ipv6IfLastChange:            not reliable so not enabled

>IPV6-MIB::ipv6IfStatsTable
>    All implemented. Requires 'SIOCGIFSTAT_IN6' to be defined.
>    This value is then used to make an ioctl() call. I don't
>    have this defined on my system. So can not verify this.
>
>IPV6-MIB::ipv6AddrPrefixTable
>IPV6-MIB::ipv6AddrTable
>IPV6-MIB::ipv6RouteNumber
>IPV6-MIB::ipv6DiscardedRoutes
>IPV6-MIB::ipv6RouteTable
>IPV6-MIB::ipv6NetToMideaTable
>IPV6-MIB::ipv6Notifications
>    All not implemented.

>IPV6-ICMP-MIB::ipv6IfIcmpTable
>    All implemented. Requires 'SIOCGIFSTAT_ICMP6' defined.
>    This value is then used to make an ioctl() call. I don't
>    have this defined on my system. So can not verify this.

   You should build ipv6 module and then load it to check the
existing support at least.

>IPV6-TCP-MIB::ipv6TcpConnTable
>    All implemented. Needs 'netinet6/tcp6.h'. I do not have
>    'netinet6' on my system. So can not verify this.

  netinet6 do not exist for linux. But you could add tcp6.h just like
  USAGI did (they included transp_v6.h under net directory). both v6 and v6
  header files are kept in /usr/inc*/linux.
  netinet6 is a BSD thing I think.

>IPV6-UCD-MIB::ipv6UdpTable
>    All implemented. But could not verify by snmpwalk somehow.
>    Maybe I do not have it setup correctly.

Thanks,
Venkat