[inet-admins] Re: [inet-admins] фильтрация BGP

["Vladimir A. Jakovenko" <vovik@lucky.net>]

On Thu, Apr 11, 2002 at 06:44:49PM +0300, Vladimir Litovka wrote:
>Hi,
>
> а насколько велик риск столкнуться с фильтрованием блоков сетей, меньших
> чем minimum allocation для диапазона? Сталкивался кто-то с таким подходом
> вживую или это только страшная теория? Я хочу из /18 выделить кусок /23 и
> думаю - не будет-ли это где-то цинично зафильтровано?

Вот кусок старого Weekly Routing Table Report (http://www.apnic.net/stats/bgp):

Analysis Summary
----------------

BGP routing table entries examined:                            107865
    Prefixes after maximum aggregation:                         71870
    Unique aggregates announced to Internet:                    51605
Total ASes present in the Internet Routing Table:               12551
Origin-only ASes present in the Internet Routing Table:         10860
Origin ASes announcing only one prefix:                          4759
Transit ASes present in the Internet Routing Table:              1691
Transit-only ASes present in the Internet Routing Table:           55
Average AS path length visible in the Internet Routing Table:     5.4
    Max AS path length visible:                                    19
Illegal AS announcements present in the Routing Table:              2
Non-routable prefixes present in the Routing Table:                 0
Prefixes being announced from the IANA Reserved Address blocks:    14
Number of addresses announced to Internet:                 1172878088
    Equivalent to 69 /8s, 232 /16s and 179 /24s
    Percentage of available address space announced:             31.6
    Percentage of allocated address space announced:             59.9
    Percentage of available address space allocated:             52.8
Total number of prefixes smaller than registry allocations:     71809

обратите внимание на первую и последнюю цифры. Селяви :-(

AFAIK при нормально созданном route-object-е вплоть до /24 в фильтр попасть 
сложно.

-- 
Regards,
Vladimir.


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