Apologies if this is too naive to ask but is there some detail available about the items listed in the summary?

1) In particular, what exactly is the difference between the "BGP routing table entries examined (292961)" and "Unique aggregates announced to Internet (145391)"?

2) I believe 292961 is the worst case routing table size for any router. If the unique aggregates announced to the Internet is 145391, how does the routing table size anywhere may exceeds this number? Is the word "Internet" the key here?

3) Is aggregation done at a particular router for (i) reducing the table size in that router, or (ii) reducing the number of announced prefixes by that router, or (iii) both?

Zartash

On Fri, Jul 31, 2009 at 11:12 PM, Routing Analysis Role Account <cscora@apnic.net> wrote:
This is an automated weekly mailing describing the state of the Internet
Routing Table as seen from APNIC's router in Japan.
Daily listings are sent to bgp-stats@lists.apnic.net

For historical data, please see http://thyme.apnic.net.

If you have any comments please contact Philip Smith <pfs@cisco.com>.

Routing Table Report   04:00 +10GMT Sat 01 Aug, 2009

Report Website:     http://thyme.apnic.net
Detailed Analysis:  http://thyme.apnic.net/current/

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

BGP routing table entries examined:                              292961
   Prefixes after maximum aggregation:                          138493
   Deaggregation factor:                                          2.12
   Unique aggregates announced to Internet:                     145391
Total ASes present in the Internet Routing Table:                 31852
   Prefixes per ASN:                                              9.20
Origin-only ASes present in the Internet Routing Table:           27681
Origin ASes announcing only one prefix:                           13518
Transit ASes present in the Internet Routing Table:                4171
Transit-only ASes present in the Internet Routing Table:            105
Average AS path length visible in the Internet Routing Table:       3.6
   Max AS path length visible:                                      24
   Max AS path prepend of ASN (12026)                               22
Prefixes from unregistered ASNs in the Routing Table:               456
   Unregistered ASNs in the Routing Table:                         130
Number of 32-bit ASNs allocated by the RIRs:                        220
Prefixes from 32-bit ASNs in the Routing Table:                      81
Special use prefixes present in the Routing Table:                    0
Prefixes being announced from unallocated address space:            340
Number of addresses announced to Internet:                   2082757696
   Equivalent to 124 /8s, 36 /16s and 92 /24s
   Percentage of available address space announced:               56.2
   Percentage of allocated address space announced:               65.0
   Percentage of available address space allocated:               86.4
   Percentage of address space in use by end-sites:               78.5
Total number of prefixes smaller than registry allocations:      140414

APNIC Region Analysis Summary
-----------------------------

Prefixes being announced by APNIC Region ASes:                    70058
   Total APNIC prefixes after maximum aggregation:               24829
   APNIC Deaggregation factor:                                    2.82
Prefixes being announced from the APNIC address blocks:           69476
   Unique aggregates announced from the APNIC address blocks:    31605
APNIC Region origin ASes present in the Internet Routing Table:    3717
   APNIC Prefixes per ASN:                                       18.69
APNIC Region origin ASes announcing only one prefix:               1012
APNIC Region transit ASes present in the Internet Routing Table:    579
Average APNIC Region AS path length visible:                        3.5
   Max APNIC Region AS path length visible:                         16
Number of APNIC addresses announced to Internet:              475903680
   Equivalent to 28 /8s, 93 /16s and 182 /24s
   Percentage of available APNIC address space announced:         88.6

APNIC AS Blocks        4608-4864, 7467-7722, 9216-10239, 17408-18431
(pre-ERX allocations)  23552-24575, 37888-38911, 45056-46079
APNIC Address Blocks    58/8,  59/8,  60/8,  61/8, 110/8, 111/8, 112/8,
                      113/8, 114/8, 115/8, 116/8, 117/8, 118/8, 119/8,
                      120/8, 121/8, 122/8, 123/8, 124/8, 125/8, 126/8,
                      180/8, 183/8, 202/8, 203/8, 210/8, 211/8, 218/8,
                      219/8, 220/8, 221/8, 222/8,

ARIN Region Analysis Summary
----------------------------

Prefixes being announced by ARIN Region ASes:                    124431
   Total ARIN prefixes after maximum aggregation:                66173
   ARIN Deaggregation factor:                                     1.88
Prefixes being announced from the ARIN address blocks:           125090
   Unique aggregates announced from the ARIN address blocks:     52293
ARIN Region origin ASes present in the Internet Routing Table:    13139
   ARIN Prefixes per ASN:                                         9.52
ARIN Region origin ASes announcing only one prefix:                5077
ARIN Region transit ASes present in the Internet Routing Table:    1287
Average ARIN Region AS path length visible:                         3.3
   Max ARIN Region AS path length visible:                          24
Number of ARIN addresses announced to Internet:              1012769216
   Equivalent to 60 /8s, 93 /16s and 161 /24s
   Percentage of available ARIN address space announced:          88.8

ARIN AS Blocks         1-1876, 1902-2042, 2044-2046, 2048-2106
(pre-ERX allocations)  2138-2584, 2615-2772, 2823-2829, 2880-3153
                      3354-4607, 4865-5119, 5632-6655, 6912-7466
                      7723-8191, 10240-12287, 13312-15359, 16384-17407
                      18432-20479, 21504-23551, 25600-26591,
                      26624-27647, 29696-30719, 31744-33791
                      35840-36863, 39936-40959, 46080-47103
                      53248-55295
ARIN Address Blocks      3/8,   4/8,   6/8,   7/8,   8/8,   9/8,  11/8,
                       12/8,  13/8,  15/8,  16/8,  17/8,  18/8,  19/8,
                       20/8,  21/8,  22/8,  24/8,  26/8,  28/8,  29/8,
                       30/8,  32/8,  33/8,  34/8,  35/8,  38/8,  40/8,
                       44/8,  45/8,  47/8,  48/8,  52/8,  54/8,  55/8,
                       56/8,  63/8,  64/8,  65/8,  66/8,  67/8,  68/8,
                       69/8,  70/8,  71/8,  72/8,  73/8,  74/8,  75/8,
                       76/8,  96/8,  97/8,  98/8,  99/8, 108/8, 173/8,
                      174/8, 184/8, 199/8, 204/8, 205/8, 206/8, 207/8,
                      208/8, 209/8, 214/8, 215/8, 216/8,

RIPE Region Analysis Summary
----------------------------

Prefixes being announced by RIPE Region ASes:                     67087
   Total RIPE prefixes after maximum aggregation:                39643
   RIPE Deaggregation factor:                                     1.69
Prefixes being announced from the RIPE address blocks:            66684
   Unique aggregates announced from the RIPE address blocks:     44964
RIPE Region origin ASes present in the Internet Routing Table:    13340
   RIPE Prefixes per ASN:                                         5.00
RIPE Region origin ASes announcing only one prefix:                6980
RIPE Region transit ASes present in the Internet Routing Table:    1995
Average RIPE Region AS path length visible:                         4.0
   Max RIPE Region AS path length visible:                          21
Number of RIPE addresses announced to Internet:               498967744
   Equivalent to 29 /8s, 189 /16s and 164 /24s
   Percentage of available RIPE address space announced:          99.1

RIPE AS Blocks         1877-1901, 2043, 2047, 2107-2136, 2585-2614
(pre-ERX allocations)  2773-2822, 2830-2879, 3154-3353, 5377-5631
                      6656-6911, 8192-9215, 12288-13311, 15360-16383
                      20480-21503, 24576-25599, 28672-29695
                      30720-31743, 33792-35839, 38912-39935
                      40960-45055, 47104-52223
RIPE Address Blocks     25/8,  51/8,  62/8,  77/8,  78/8,  79/8,  80/8,
                       81/8,  82/8,  83/8,  84/8,  85/8,  86/8,  87/8,
                       88/8,  89/8,  90/8,  91/8,  92/8,  93/8,  94/8,
                       95/8, 109/8, 178/8, 193/8, 194/8, 195/8, 212/8,
                      213/8, 217/8,

LACNIC Region Analysis Summary
------------------------------

Prefixes being announced by LACNIC Region ASes:                   24832
   Total LACNIC prefixes after maximum aggregation:               6078
   LACNIC Deaggregation factor:                                   4.09
Prefixes being announced from the LACNIC address blocks:          24789
   Unique aggregates announced from the LACNIC address blocks:   13736
LACNIC Region origin ASes present in the Internet Routing Table:   1147
   LACNIC Prefixes per ASN:                                      21.61
LACNIC Region origin ASes announcing only one prefix:               367
LACNIC Region transit ASes present in the Internet Routing Table:   192
Average LACNIC Region AS path length visible:                       4.0
   Max LACNIC Region AS path length visible:                        23
Number of LACNIC addresses announced to Internet:              72874176
   Equivalent to 4 /8s, 87 /16s and 248 /24s
   Percentage of available LACNIC address space announced:        72.4

LACNIC AS Blocks       26592-26623, 27648-28671, 52224-53247
                      plus ERX transfers
LACNIC Address Blocks  186/8, 187/8, 189/8, 190/8, 200/8, 201/8,

AfriNIC Region Analysis Summary
-------------------------------

Prefixes being announced by AfriNIC Region ASes:                   6163
   Total AfriNIC prefixes after maximum aggregation:              1482
   AfriNIC Deaggregation factor:                                  4.16
Prefixes being announced from the AfriNIC address blocks:          6569
   Unique aggregates announced from the AfriNIC address blocks:   2514
AfriNIC Region origin ASes present in the Internet Routing Table:   299
   AfriNIC Prefixes per ASN:                                     21.97
AfriNIC Region origin ASes announcing only one prefix:               82
AfriNIC Region transit ASes present in the Internet Routing Table:   61
Average AfriNIC Region AS path length visible:                      3.8
   Max AfriNIC Region AS path length visible:                       16
Number of AfriNIC addresses announced to Internet:             20273152
   Equivalent to 1 /8s, 53 /16s and 88 /24s
   Percentage of available AfriNIC address space announced:       60.4

AfriNIC AS Blocks      36864-37887 & ERX transfers
AfriNIC Address Blocks  41/8, 197/8,

APNIC Region per AS prefix count summary
----------------------------------------

 ASN   No of nets  /20 equiv  MaxAgg  Description
 4766     1714       6976         419   Korea Telecom (KIX)
17488     1543        137         103   Hathway IP Over Cable Interne
 4755     1227        292         145   TATA Communications formerly
 9583     1114         87         548   Sify Limited
 4134      980      17389         381   CHINANET-BACKBONE
 7545      807        198         101   TPG Internet Pty Ltd
 9829      807        619          15   BSNL National Internet Backbo
23577      785         34         666   Korea Telecom (ATM-MPLS)
 4808      754       1515         172   CNCGROUP IP network: China169
18101      750        201          32   Reliance Infocom Ltd Internet

Complete listing at http://thyme.apnic.net/current/data-ASnet-APNIC

ARIN Region per AS prefix count summary
---------------------------------------

 ASN   No of nets  /20 equiv  MaxAgg  Description
 6389     4224       3643         323   bellsouth.net, inc.
 4323     1912       1048         386   Time Warner Telecom
 1785     1719        714         138   PaeTec Communications, Inc.
 7018     1511       5907        1047   AT&T WorldNet Services
20115     1428       1464         679   Charter Communications
 2386     1265        669         921   AT&T Data Communications Serv
 6478     1249        274         302   AT&T Worldnet Services
 3356     1201      10963         443   Level 3 Communications, LLC
11492     1129        208          12   Cable One
22773     1079       2604          66   Cox Communications, Inc.

Complete listing at http://thyme.apnic.net/current/data-ASnet-ARIN

RIPE Region per AS prefix count summary
---------------------------------------

 ASN   No of nets  /20 equiv  MaxAgg  Description
30890      483         92         195   Evolva Telecom
12479      470        578           6   Uni2 Autonomous System
 3292      460       1905         395   TDC Tele Danmark
 702      430       1861         346   UUNET - Commercial IP service
 9198      367        138          12   Kazakhtelecom Data Network Ad
 3320      353       7083         306   Deutsche Telekom AG
 3301      347       1684         310   TeliaNet Sweden
 3215      344       3081         109   France Telecom Transpac
 8866      335        109          20   Bulgarian Telecommunication C
 8551      310        290          38   Bezeq International

Complete listing at http://thyme.apnic.net/current/data-ASnet-RIPE

LACNIC Region per AS prefix count summary
-----------------------------------------

 ASN   No of nets  /20 equiv  MaxAgg  Description
 8151     1504       2898         245   UniNet S.A. de C.V.
10620      964        220         107   TVCABLE BOGOTA
28573      637        579          41   NET Servicos de Comunicao S.A
 7303      601        320          94   Telecom Argentina Stet-France
22047      539        302          14   VTR PUNTO NET S.A.
11830      489        310          54   Instituto Costarricense de El
11172      443         99          69   Servicios Alestra S.A de C.V
 6471      421         96          31   ENTEL CHILE S.A.
 7738      410        858          29   Telecomunicacoes da Bahia S.A
 3816      386        189          80   Empresa Nacional de Telecomun

Complete listing at http://thyme.apnic.net/current/data-ASnet-LACNIC

AfriNIC Region per AS prefix count summary
------------------------------------------

 ASN   No of nets  /20 equiv  MaxAgg  Description
 8452     1025        188           7   TEDATA
24863      908         90          48   LINKdotNET AS number
20858      324         34           5   EgyNet
 3741      277        856         237   The Internet Solution
 2018      245        215         143   Tertiary Education Network
 6713      176        166          16   Itissalat Al-MAGHRIB
33783      152         10           8   EEPAD TISP TELECOM & INTERNET
24835      138         46           9   RAYA Telecom - Egypt
29571      138         14           6   Ci Telecom Autonomous system
 5536      123          8           9   Internet Egypt Network

Complete listing at http://thyme.apnic.net/current/data-ASnet-AFRINIC

Global Per AS prefix count summary
----------------------------------

 ASN   No of nets  /20 equiv  MaxAgg  Description
 6389     4224       3643         323   bellsouth.net, inc.
 4323     1912       1048         386   Time Warner Telecom
 1785     1719        714         138   PaeTec Communications, Inc.
 4766     1714       6976         419   Korea Telecom (KIX)
17488     1543        137         103   Hathway IP Over Cable Interne
 7018     1511       5907        1047   AT&T WorldNet Services
 8151     1504       2898         245   UniNet S.A. de C.V.
20115     1428       1464         679   Charter Communications
 2386     1265        669         921   AT&T Data Communications Serv
 6478     1249        274         302   AT&T Worldnet Services

Complete listing at http://thyme.apnic.net/current/data-ASnet

Global Per AS Maximum Aggr summary
----------------------------------

 ASN   No of nets  Net Savings Description
 1785      1719        1581      PaeTec Communications, Inc.
 4323      1912        1526      Time Warner Telecom
17488      1543        1440      Hathway IP Over Cable Interne
 4766      1714        1295      Korea Telecom (KIX)
 8151      1504        1259      UniNet S.A. de C.V.
11492      1129        1117      Cable One
 4755      1227        1082      TATA Communications formerly
18566      1062        1052      Covad Communications
 8452      1025        1018      TEDATA
22773      1079        1013      Cox Communications, Inc.

Complete listing at http://thyme.apnic.net/current/data-CIDRnet

List of Unregistered Origin ASNs (Global)
-----------------------------------------

Bad AS  Designation  Network              Transit AS  Description
16927   UNALLOCATED   12.0.252.0/23         7018       AT&T WorldNet Servic
15132   UNALLOCATED   12.9.150.0/24         7018       AT&T WorldNet Servic
32567   UNALLOCATED   12.14.170.0/24        7018       AT&T WorldNet Servic
13746   UNALLOCATED   12.24.56.0/24         7018       AT&T WorldNet Servic
32567   UNALLOCATED   12.25.107.0/24        7018       AT&T WorldNet Servic
26973   UNALLOCATED   12.39.152.0/24        7018       AT&T WorldNet Servic
26973   UNALLOCATED   12.39.154.0/23        7018       AT&T WorldNet Servic
26973   UNALLOCATED   12.39.159.0/24        7018       AT&T WorldNet Servic
32326   UNALLOCATED   12.40.49.0/24         7018       AT&T WorldNet Servic
25639   UNALLOCATED   12.41.169.0/24        7018       AT&T WorldNet Servic

Complete listing at http://thyme.apnic.net/current/data-badAS

Advertised Unallocated Addresses
--------------------------------

Network            Origin AS  Description
41.223.92.0/22       36936     >>UNKNOWN<<
41.223.112.0/22       5713     Telkom SA Ltd
41.223.176.0/22      36981     >>UNKNOWN<<
41.223.188.0/24      22351     Intelsat
41.223.189.0/24      26452     Local Communications Networks
62.61.220.0/24       24974     Tachyon Europe BV - Wireless
62.61.221.0/24       24974     Tachyon Europe BV - Wireless
63.140.213.0/24      22555     Universal Talkware Corporatio
63.143.251.0/24      22555     Universal Talkware Corporatio
64.31.32.0/19        11955     ServiceCo LLC - Road Runner

Complete listing at http://thyme.apnic.net/current/data-add-IANA

Number of prefixes announced per prefix length (Global)
-------------------------------------------------------

 /1:0        /2:0        /3:0        /4:0        /5:0        /6:0
 /7:0        /8:19       /9:10      /10:24      /11:58      /12:169
/13:350     /14:619     /15:1171    /16:10574   /17:4763    /18:8324
/19:17206   /20:20600   /21:20446   /22:26358   /23:26224   /24:153360
/25:904     /26:1027    /27:574     /28:157     /29:8       /30:7
/31:1       /32:8

Advertised prefixes smaller than registry allocations
-----------------------------------------------------

 ASN   No of nets  Total ann.   Description
 6389     2740          4224      bellsouth.net, inc.
 4766     1400          1714      Korea Telecom (KIX)
17488     1290          1543      Hathway IP Over Cable Interne
 1785     1189          1719      PaeTec Communications, Inc.
11492     1055          1129      Cable One
18566     1043          1062      Covad Communications
 4323      967          1912      Time Warner Telecom
 9583      967          1114      Sify Limited
 8452      947          1025      TEDATA
10620      872           964      TVCABLE BOGOTA

Complete listing at http://thyme.apnic.net/current/data-sXXas-nos

Number of /24s announced per /8 block (Global)
----------------------------------------------

  4:14        8:210      12:2134     13:7        15:19       16:3
 17:5        20:35       24:1111     32:52       34:2        38:583
 40:98       41:1721     43:1        44:2        47:22       52:6
 53:2        55:2        56:2        57:24       58:597      59:649
 60:462      61:1081     62:1111     63:2004     64:3704     65:2407
 66:3583     67:1680     68:860      69:2731     70:550      71:152
 72:1652     73:2        74:1644     75:175      76:340      77:849
 78:586      79:355      80:955      81:852      82:591      83:453
 84:634      85:1063     86:372      87:670      88:373      89:1479
 90:50       91:2425     92:384      93:1090     94:1107     95:1194
 96:157      97:240      98:256      99:28      110:168     111:365
 112:117     113:147     114:241     115:350     116:1119    117:555
 118:338     119:757     120:147     121:782     122:1056    123:685
 124:980     125:1377    128:225     129:222     130:128     131:414
 132:74      133:10      134:186     135:43      136:224     137:165
 138:167     139:82      140:446     141:123     142:384     143:377
 144:361     145:48      146:390     147:152     148:529     149:221
 150:206     151:193     152:145     153:148     154:2       155:275
 156:167     157:301     158:118     159:343     160:289     161:156
 162:272     163:165     164:474     165:515     166:466     167:361
 168:709     169:176     170:481     171:41      172:10      173:324
 174:269     178:1       180:4       186:109     187:145     188:350
 189:573     190:2941    192:5790    193:4259    194:3298    195:2692
 196:1127    198:3641    199:3363    200:5133    201:1285    202:7740
 203:8287    204:3892    205:2135    206:2443    207:2737    208:3893
 209:3449    210:2534    211:1106    212:1662    213:1618    214:80
 215:29      216:4550    217:1365    218:405     219:450     220:1104
 221:479     222:328

End of report