IPv4 R&E Routing Table Report 22:20 GMT Thu 25 Sep, 2025 IPv4 BGP Table (R&E) as seen at ESnet. Report Website: https://bgp.nsrc.org/REN Detailed Analysis: https://bgp.nsrc.org/REN/ESnet/ Analysis Summary ---------------- BGP routing table entries examined: 19054 Prefixes after maximum aggregation (per Origin AS): 10455 Deaggregation factor: 1.82 Unique aggregates announced (without unneeded subnets): 11650 Number of IPv4 prefixes with a valid ROA: 8136 Number of IPv4 prefixes with an invalid ROA: 1 Number of IPv4 prefixes with no ROA: 10917 Total ASes present in the Internet Routing Table: 2731 Prefixes per ASN: 6.98 Origin-only ASes present in the Internet Routing Table: 2385 Origin ASes announcing only one prefix: 1071 Transit ASes present in the Internet Routing Table: 346 Transit-only ASes present in the Internet Routing Table: 44 Paths with bogon ASNs present in the IPv4 Routing Table: 0 Average AS path length visible in the Internet Routing Table: 4.0 Max AS path length visible: 16 Max AS path prepend of ASN (395156) 12 Prefixes from unregistered ASNs in the Routing Table: 33 Number of instances of unregistered ASNs: 33 Number of 32-bit ASNs allocated by the RIRs: 47551 Number of 32-bit ASNs visible in the Routing Table: 702 Prefixes from 32-bit ASNs in the Routing Table: 1896 Number of bogon 32-bit ASNs visible in the Routing Table: 0 Special use prefixes present in the Routing Table: 0 Prefixes being announced from unallocated address space: 2 Number of addresses announced to Internet: 167975680 Equivalent to 10 /8s, 3 /16s and 27 /24s Percentage of available address space announced: 4.5 Percentage of allocated address space announced: 4.5 Percentage of available address space allocated: 100.0 Percentage of address space in use by end-sites: 99.6 Total number of prefixes smaller than registry allocations: 2316 APNIC Region Analysis Summary ----------------------------- Prefixes being announced by APNIC Region ASes: 4710 Total APNIC prefixes after maximum aggregation: 2319 APNIC Deaggregation factor: 2.03 Prefixes being announced from the APNIC address blocks: 4709 Unique aggregates announced from the APNIC address blocks: 2670 APNIC Region origin ASes present in the Internet Routing Table: 586 APNIC Prefixes per ASN: 8.04 APNIC Region origin ASes announcing only one prefix: 244 APNIC Region transit ASes present in the Internet Routing Table: 50 Average APNIC Region AS path length visible: 3.8 Max APNIC Region AS path length visible: 12 Number of APNIC region 32-bit ASNs visible in the Routing Table: 235 Number of APNIC addresses announced to Internet: 35737600 Equivalent to 2 /8s, 33 /16s and 80 /24s APNIC AS Blocks 4608-4864, 7467-7722, 9216-10239, 17408-18431 (pre-ERX allocations) 23552-24575, 37888-38911, 45056-46079, 55296-56319, 58368-59391, 63488-64098, 64297-64395, 131072-155961 APNIC Address Blocks 1/8, 14/8, 27/8, 36/8, 39/8, 42/8, 43/8, 49/8, 58/8, 59/8, 60/8, 61/8, 101/8, 103/8, 106/8, 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, 133/8, 150/8, 153/8, 163/8, 171/8, 175/8, 180/8, 182/8, 183/8, 202/8, 203/8, 210/8, 211/8, 218/8, 219/8, 220/8, 221/8, 222/8, 223/8, ARIN Region Analysis Summary ---------------------------- Prefixes being announced by ARIN Region ASes: 8423 Total ARIN prefixes after maximum aggregation: 4684 ARIN Deaggregation factor: 1.80 Prefixes being announced from the ARIN address blocks: 8466 Unique aggregates announced from the ARIN address blocks: 5217 ARIN Region origin ASes present in the Internet Routing Table: 1277 ARIN Prefixes per ASN: 6.63 ARIN Region origin ASes announcing only one prefix: 456 ARIN Region transit ASes present in the Internet Routing Table: 153 Average ARIN Region AS path length visible: 4.0 Max ARIN Region AS path length visible: 16 Number of ARIN region 32-bit ASNs visible in the Routing Table: 228 Number of ARIN addresses announced to Internet: 72690944 Equivalent to 4 /8s, 85 /16s and 45 /24s 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, 62464-63487, 64198-64296, 393216-402332 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, 23/8, 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, 50/8, 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, 100/8, 104/8, 107/8, 108/8, 128/8, 129/8, 130/8, 131/8, 132/8, 134/8, 135/8, 136/8, 137/8, 138/8, 139/8, 140/8, 142/8, 143/8, 144/8, 146/8, 147/8, 148/8, 149/8, 152/8, 155/8, 156/8, 157/8, 158/8, 159/8, 160/8, 161/8, 162/8, 164/8, 165/8, 166/8, 167/8, 168/8, 169/8, 170/8, 172/8, 173/8, 174/8, 184/8, 192/8, 198/8, 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: 3514 Total RIPE prefixes after maximum aggregation: 2812 RIPE Deaggregation factor: 1.25 Prefixes being announced from the RIPE address blocks: 3505 Unique aggregates announced from the RIPE address blocks: 2907 RIPE Region origin ASes present in the Internet Routing Table: 652 RIPE Prefixes per ASN: 5.38 RIPE Region origin ASes announcing only one prefix: 297 RIPE Region transit ASes present in the Internet Routing Table: 103 Average RIPE Region AS path length visible: 3.7 Max RIPE Region AS path length visible: 13 Number of RIPE region 32-bit ASNs visible in the Routing Table: 155 Number of RIPE addresses announced to Internet: 53148672 Equivalent to 3 /8s, 42 /16s and 252 /24s 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, 56320-58367 59392-61439, 61952-62463, 64396-64495 196608-216475 RIPE Address Blocks 2/8, 5/8, 25/8, 31/8, 37/8, 46/8, 51/8, 53/8, 57/8, 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, 141/8, 145/8, 151/8, 176/8, 178/8, 185/8, 188/8, 193/8, 194/8, 195/8, 212/8, 213/8, 217/8, LACNIC Region Analysis Summary ------------------------------ Prefixes being announced by LACNIC Region ASes: 1199 Total LACNIC prefixes after maximum aggregation: 463 LACNIC Deaggregation factor: 2.59 Prefixes being announced from the LACNIC address blocks: 1198 Unique aggregates announced from the LACNIC address blocks: 631 LACNIC Region origin ASes present in the Internet Routing Table: 118 LACNIC Prefixes per ASN: 10.15 LACNIC Region origin ASes announcing only one prefix: 46 LACNIC Region transit ASes present in the Internet Routing Table: 21 Average LACNIC Region AS path length visible: 4.3 Max LACNIC Region AS path length visible: 12 Number of LACNIC region 32-bit ASNs visible in the Routing Table: 54 Number of LACNIC addresses announced to Internet: 3918336 Equivalent to 0 /8s, 59 /16s and 202 /24s LACNIC AS Blocks 26592-26623, 27648-28671, 52224-53247, 61440-61951, 64099-64197, 262144-274844 + ERX transfers LACNIC Address Blocks 177/8, 179/8, 181/8, 186/8, 187/8, 189/8, 190/8, 191/8, 200/8, 201/8, AfriNIC Region Analysis Summary ------------------------------- Prefixes being announced by AfriNIC Region ASes: 1175 Total AfriNIC prefixes after maximum aggregation: 171 AfriNIC Deaggregation factor: 6.87 Prefixes being announced from the AfriNIC address blocks: 1174 Unique aggregates announced from the AfriNIC address blocks: 223 AfriNIC Region origin ASes present in the Internet Routing Table: 51 AfriNIC Prefixes per ASN: 23.02 AfriNIC Region origin ASes announcing only one prefix: 28 AfriNIC Region transit ASes present in the Internet Routing Table: 9 Average AfriNIC Region AS path length visible: 4.7 Max AfriNIC Region AS path length visible: 9 Number of AfriNIC region 32-bit ASNs visible in the Routing Table: 30 Number of AfriNIC addresses announced to Internet: 2477824 Equivalent to 0 /8s, 37 /16s and 207 /24s AfriNIC AS Blocks 36864-37887, 327680-329727 & ERX transfers AfriNIC Address Blocks 41/8, 102/8, 105/8, 154/8, 196/8, 197/8, APNIC Region per AS prefix count summary ---------------------------------------- ASN No of nets /20 equiv MaxAgg Description 2907 598 2168 460 SINET-AS Research Organization of Informa 7497 452 180 23 CSTNET-AS-AP Computer Network Information 1237 195 72 151 KREONET-AS-KR KISTI, KR 58647 182 18 2 KAGAWAU-AS Kagawa University, JP 7575 167 281 111 AARNET-AS-AP Australian Academic and Rese 4538 163 2401 79 ERX-CERNET-BKB China Education and Resear 55824 149 19 21 NKN-CORE-NW NKN Core Network, IN 4762 75 4 1 MAHIDOL-BORDER-AS Mahidol University, Tha 6262 63 134 56 CSIRO Commonwealth Scientific and Industr 23570 59 5 11 INCHEON-AS-KR UNIVERSITY OF INCHEON, KR Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet-APNIC ARIN Region per AS prefix count summary --------------------------------------- ASN No of nets /20 equiv MaxAgg Description 2152 615 492 99 CENIC-2152, US 2920 230 44 49 LACOE, US 376 200 162 150 RISQ-AS, CA 5786 192 16 1 UPRENET, PR 18558 139 18 5 NETBLK-RCOEK, US 81 127 471 35 NCREN, US 21976 88 34 14 NJEDGE-NET, US 237 84 542 50 MERIT-AS-14, US 1736 79 16 1 MU-AS, US 3477 79 79 37 NOAA-NWAVE, US Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet-ARIN RIPE Region per AS prefix count summary --------------------------------------- ASN No of nets /20 equiv MaxAgg Description 680 282 1883 249 DFN Verein zur Foerderung eines Deutschen 786 187 1742 183 JANET Jisc Services Limited, GB 559 114 533 104 SWITCH Switch, Swiss Academic and Researc 8895 108 24 5 ISU Internet Services Unit ISU, SA 1103 98 1247 84 SURFNET-NL SURFnet, The Netherlands, NL 2614 89 26 69 ROEDUNET, RO 137 82 677 77 ASGARR Consortium GARR, IT 3267 80 29 69 NIKS, RU 1930 77 88 72 RCCN Fundacao para a Ciencia e a Tecnolog 553 75 366 75 BELWUE BelWue-Koordination, DE Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet-RIPE LACNIC Region per AS prefix count summary ----------------------------------------- ASN No of nets /20 equiv MaxAgg Description 1916 204 177 41 Rede Nacional de Ensino e Pesquisa, BR 28391 159 10 71 Universidad Juarez Autonoma de Tabasco, M 11340 111 25 50 Red Universitaria Nacional, CL 271640 68 8 1 UNIVERSIDADE FEDERAL DE VICOSA, BR 61468 52 3 21 CEDIA, EC 19611 49 17 2 Associacao Antonio Vieira - Unisinos, BR 2715 45 99 33 Fundacao Carlos Chagas Filho de Amparo a 28614 38 2 2 Fundacao Universidade Regional de Blumena 1251 37 31 26 FUNDACAO DE AMPARO A PESQUISA DO ESTADO S 3596 37 8 4 Universidad Autonoma Metropolitana, MX Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet-LACNIC AfriNIC Region per AS prefix count summary ------------------------------------------ ASN No of nets /20 equiv MaxAgg Description 36914 575 82 3 KENET-AS, KE 2018 376 318 69 TENET-1, ZA 8094 47 48 18 PUKNET, ZA 37215 39 8 1 MAREN, MW 6879 24 2 9 ENSTINET-, EG 327700 13 16 1 MoRENet, MZ 37501 11 49 6 UOFS, ZA 37654 10 1 6 RwEdNet-AS, RW 36982 8 33 8 UCT, ZA 327947 6 4 1 KNUST-, GH Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet-AFRINIC Global Per AS prefix count summary ---------------------------------- ASN No of nets /20 equiv MaxAgg Description 2152 615 492 99 CENIC-2152, US 2907 598 2168 460 SINET-AS Research Organization of Informa 36914 575 82 3 KENET-AS, KE 7497 452 180 23 CSTNET-AS-AP Computer Network Information 2018 376 318 69 TENET-1, ZA 680 282 1883 249 DFN Verein zur Foerderung eines Deutschen 2920 230 44 49 LACOE, US 1916 204 177 41 Rede Nacional de Ensino e Pesquisa, BR 376 200 162 150 RISQ-AS, CA 1237 195 72 151 KREONET-AS-KR KISTI, KR Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet Global Per AS Maximum Aggregation summary ----------------------------------------- ASN No of nets Net Savings Description 36914 575 572 KENET-AS, KE 7497 452 429 CSTNET-AS-AP Computer Network Information Cente 2018 376 307 TENET-1, ZA 5786 192 191 UPRENET, PR 2920 230 181 LACOE, US 58647 182 180 KAGAWAU-AS Kagawa University, JP 1916 204 163 Rede Nacional de Ensino e Pesquisa, BR 2907 598 138 SINET-AS Research Organization of Information a 18558 139 134 NETBLK-RCOEK, US 55824 149 128 NKN-CORE-NW NKN Core Network, IN Complete listing at https://bgp.nsrc.org/REN/ESnet/data-CIDRnet List of Unregistered Origin ASNs (Global) ----------------------------------------- Bad AS Designation Net Originated Transit AS Transit AS Name 26971 UNALLOCATED 129.111.0.0/16 276 OTS-AS-276, US 26898 UNALLOCATED 131.187.248.0/22 3112 OARNET-AS-1, US 26898 UNALLOCATED 131.187.248.0/24 3112 OARNET-AS-1, US 26898 UNALLOCATED 131.187.249.0/24 3112 OARNET-AS-1, US 26898 UNALLOCATED 131.187.250.0/24 3112 OARNET-AS-1, US 26898 UNALLOCATED 131.187.251.0/24 3112 OARNET-AS-1, US 26898 UNALLOCATED 198.30.187.0/24 3112 OARNET-AS-1, US 22272 UNALLOCATED 206.208.24.0/21 6325 ILLINOIS-CENTURY, US 26898 UNALLOCATED 208.108.80.0/20 3112 OARNET-AS-1, US 26898 UNALLOCATED 208.108.80.0/24 3112 OARNET-AS-1, US Complete listing at https://bgp.nsrc.org/REN/ESnet/data-badAS Advertised Unallocated Addresses -------------------------------- Unassigned Network ASN Information AS Name 164.160.192.0/21 Origin: 37661 NRaE1-AS, NG 164.160.192.0/21 Transit: 37288 WACREN, SN 203.9.156.0/24 Origin: 1851 ADELAIDE-UNIVERSITY-AS-AP The University 203.9.156.0/24 Transit: 7575 AARNET-AS-AP Australian Academic and Res Complete listing at https://bgp.nsrc.org/REN/ESnet/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 /8:0 /9:0 /10:0 /11:0 /12:0 /13:0 /14:33 /15:114 /16:1925 /17:424 /18:443 /19:583 /20:838 /21:830 /22:1450 /23:1586 /24:10828 /25:0 /26:0 /27:0 /28:0 /29:0 /30:0 /31:0 /32:0 Advertised prefixes smaller than registry allocations ----------------------------------------------------- ASN No of nets Total ann. Description 36914 551 575 KENET-AS, KE 8895 105 108 ISU Internet Services Unit ISU, SA 2152 73 615 CENIC-2152, US 31638 44 44 ASN-LEPIDA, IT 3267 35 80 NIKS, RU 200521 34 58 SEAP-AGE, ES 37215 33 39 MAREN, MW 28614 32 38 Fundacao Universidade Regional de Blumenau, BR 46115 32 35 LUTHER, US 25977 30 44 HCCS, US Complete listing at https://bgp.nsrc.org/REN/ESnet/data-sXXas-nos Number of /24s announced per /8 block (Global) ---------------------------------------------- 1:2 5:16 8:2 12:2 14:93 18:39 23:11 24:3 31:1 35:4 37:26 38:13 40:1 41:227 42:18 44:5 45:41 46:4 47:1 49:12 50:4 52:1 58:14 59:20 60:6 61:3 62:6 63:36 64:47 65:21 66:56 67:44 68:19 69:19 70:2 71:1 72:8 74:54 76:27 77:9 78:3 79:9 80:10 81:27 82:5 83:6 84:5 85:47 86:3 87:1 89:15 91:38 92:2 93:13 94:2 95:2 96:5 97:1 98:2 101:3 102:11 103:349 104:74 107:2 108:8 109:8 111:5 113:1 114:21 116:7 117:61 118:33 119:31 121:12 122:8 123:8 124:42 125:5 128:57 129:43 130:97 131:69 132:65 133:156 134:111 136:193 137:110 138:10 139:5 140:33 141:4 142:27 143:25 144:45 145:2 146:137 147:52 148:201 149:11 150:36 151:10 152:124 153:14 154:41 155:87 156:128 157:23 158:29 159:117 160:32 161:29 162:30 163:70 164:9 165:43 166:2 167:28 168:102 169:6 170:26 171:1 172:1 173:6 174:1 175:16 177:4 179:12 180:16 181:1 182:12 184:4 185:49 186:3 187:23 188:21 190:17 191:13 192:1399 193:276 194:119 195:69 196:148 197:360 198:532 199:250 200:292 201:20 202:622 203:433 204:399 205:184 206:201 207:327 208:65 209:149 210:222 211:4 212:147 213:4 216:88 217:23 218:22 219:6 220:16 222:3 223:6 End of report