IPv4 R&E Routing Table Report 22:20 GMT Wed 20 May, 2026 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: 17993 Prefixes after maximum aggregation (per Origin AS): 9937 Deaggregation factor: 1.81 Unique aggregates announced (without unneeded subnets): 10967 Number of IPv4 prefixes with a valid ROA: 7772 Number of IPv4 prefixes with an invalid ROA: 1 Number of IPv4 prefixes with no ROA: 10220 Total ASes present in the Internet Routing Table: 2550 Prefixes per ASN: 7.06 Origin-only ASes present in the Internet Routing Table: 2224 Origin ASes announcing only one prefix: 976 Transit ASes present in the Internet Routing Table: 326 Transit-only ASes present in the Internet Routing Table: 43 Paths with bogon ASNs present in the IPv4 Routing Table: 0 Average AS path length visible in the Internet Routing Table: 4.1 Max AS path length visible: 16 Max AS path prepend of ASN (395156) 12 Prefixes from unregistered ASNs in the Routing Table: 3 Number of instances of unregistered ASNs: 3 Number of 32-bit ASNs allocated by the RIRs: 49818 Number of 32-bit ASNs visible in the Routing Table: 627 Prefixes from 32-bit ASNs in the Routing Table: 1739 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: 1 Number of addresses announced to Internet: 162974464 Equivalent to 9 /8s, 182 /16s and 203 /24s Percentage of available address space announced: 4.4 Percentage of allocated address space announced: 4.4 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: 2140 APNIC Region Analysis Summary ----------------------------- Prefixes being announced by APNIC Region ASes: 4621 Total APNIC prefixes after maximum aggregation: 2260 APNIC Deaggregation factor: 2.04 Prefixes being announced from the APNIC address blocks: 4620 Unique aggregates announced from the APNIC address blocks: 2538 APNIC Region origin ASes present in the Internet Routing Table: 573 APNIC Prefixes per ASN: 8.06 APNIC Region origin ASes announcing only one prefix: 239 APNIC Region transit ASes present in the Internet Routing Table: 49 Average APNIC Region AS path length visible: 4.0 Max APNIC Region AS path length visible: 15 Number of APNIC region 32-bit ASNs visible in the Routing Table: 231 Number of APNIC addresses announced to Internet: 35716352 Equivalent to 2 /8s, 32 /16s and 253 /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: 8688 Total ARIN prefixes after maximum aggregation: 4786 ARIN Deaggregation factor: 1.82 Prefixes being announced from the ARIN address blocks: 8702 Unique aggregates announced from the ARIN address blocks: 5383 ARIN Region origin ASes present in the Internet Routing Table: 1284 ARIN Prefixes per ASN: 6.78 ARIN Region origin ASes announcing only one prefix: 444 ARIN Region transit ASes present in the Internet Routing Table: 151 Average ARIN Region AS path length visible: 4.1 Max ARIN Region AS path length visible: 16 Number of ARIN region 32-bit ASNs visible in the Routing Table: 226 Number of ARIN addresses announced to Internet: 71793152 Equivalent to 4 /8s, 71 /16s and 122 /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, 393216-404380 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: 3321 Total RIPE prefixes after maximum aggregation: 2665 RIPE Deaggregation factor: 1.25 Prefixes being announced from the RIPE address blocks: 3310 Unique aggregates announced from the RIPE address blocks: 2744 RIPE Region origin ASes present in the Internet Routing Table: 594 RIPE Prefixes per ASN: 5.57 RIPE Region origin ASes announcing only one prefix: 272 RIPE Region transit ASes present in the Internet Routing Table: 99 Average RIPE Region AS path length visible: 3.6 Max RIPE Region AS path length visible: 13 Number of RIPE region 32-bit ASNs visible in the Routing Table: 151 Number of RIPE addresses announced to Internet: 52568832 Equivalent to 3 /8s, 34 /16s and 35 /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: 153 Total LACNIC prefixes after maximum aggregation: 28 LACNIC Deaggregation factor: 5.46 Prefixes being announced from the LACNIC address blocks: 153 Unique aggregates announced from the LACNIC address blocks: 28 LACNIC Region origin ASes present in the Internet Routing Table: 14 LACNIC Prefixes per ASN: 10.93 LACNIC Region origin ASes announcing only one prefix: 4 LACNIC Region transit ASes present in the Internet Routing Table: 8 Average LACNIC Region AS path length visible: 5.8 Max LACNIC Region AS path length visible: 9 Number of LACNIC region 32-bit ASNs visible in the Routing Table: 2 Number of LACNIC addresses announced to Internet: 443392 Equivalent to 0 /8s, 6 /16s and 196 /24s LACNIC AS Blocks 26592-26623, 27648-28671, 52224-53247, 61440-61951, 64099-64197, 262144-275868 + 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: 1207 Total AfriNIC prefixes after maximum aggregation: 195 AfriNIC Deaggregation factor: 6.19 Prefixes being announced from the AfriNIC address blocks: 1207 Unique aggregates announced from the AfriNIC address blocks: 273 AfriNIC Region origin ASes present in the Internet Routing Table: 39 AfriNIC Prefixes per ASN: 30.95 AfriNIC Region origin ASes announcing only one prefix: 17 AfriNIC Region transit ASes present in the Internet Routing Table: 9 Average AfriNIC Region AS path length visible: 5.1 Max AfriNIC Region AS path length visible: 10 Number of AfriNIC region 32-bit ASNs visible in the Routing Table: 17 Number of AfriNIC addresses announced to Internet: 2452480 Equivalent to 0 /8s, 37 /16s and 108 /24s AfriNIC AS Blocks 36864-37887, 327680-330751 & 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 2152 459 SINET-AS Research Organization of Informa 7497 465 212 24 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 163 281 110 AARNET-AS-AP Australian Academic and Rese 4538 162 2403 79 ERX-CERNET-BKB China Education and Resear 55824 151 19 20 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 1659 57 458 32 ERX-TANET-ASN1 Taiwan Academic Network TA 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 687 492 98 CENIC-2152 - CENIC, US 2920 226 44 49 LACOE - Los Angeles County Office of Educ 5786 197 16 1 UPRENET - University of Puerto Rico, PR 376 196 146 150 RISQ-AS - Reseau dInformations Scientifiq 18558 141 18 5 NETBLK-RCOEK - Riverside County Office of 81 115 455 35 NCREN - MCNC, US 21976 92 34 14 NJEDGE-NET - NJEDge.Net, Inc., US 3477 85 79 42 NOAA-NWAVE - National Oceanic and Atmosph 237 83 542 49 MERIT-AS-14 - Merit Network Inc., US 1736 79 16 1 MU-AS - Marquette University, 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 680 291 1883 253 DFN Verein zur Foerderung eines Deutschen 786 210 1684 192 JANET Jisc Services Limited, GB 559 115 533 105 SWITCH Switch, Swiss Academic and Researc 1103 98 1247 83 SURFNET-NL SURFnet, The Netherlands, NL 8895 98 24 5 ISU Internet Services Unit ISU, SA 2614 87 26 67 ROEDUNET, RO 137 82 677 77 ASGARR Consortium GARR, IT 1930 78 88 73 RCCN Fundacao para a Ciencia e a Tecnolog 553 75 366 75 BELWUE BelWue-Koordination, DE 2200 63 614 58 FR-RENATER Reseau National de telecommuni 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 3596 66 8 4 Universidad Autonoma Metropolitana, MX 19611 41 16 1 Associacao Antonio Vieira - Unisinos, BR 278 19 32 4 Universidad Nacional Autonoma de Mexico, 262742 8 2 1 Fundacao Universidade Federal do ABC - UF 3640 4 14 4 C I C E S E, MX 27922 3 1 3 Smithsonian Tropical Research Institute, 16596 2 2 2 Universidad Autonoma del Estado de Baja C 18592 2 0 2 Corporacion Universitaria para el Desarro 27676 2 0 2 ALMA - Atacama Large Millimeter Array, CL 52890 2 1 1 Centro Integrado de Telematica do Exercit 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 553 82 3 KENET-AS, KE 2018 374 318 69 TENET-1, ZA 2561 68 4 34 EUN, EG 8094 46 48 21 PUKNET, ZA 37215 45 8 1 MAREN, MW 6879 24 2 9 ENSTINET-, EG 327700 13 16 1 MoRENet, MZ 37501 11 49 6 UOFS, ZA 37182 10 8 1 TERNET, TZ 36982 8 33 8 UCT, ZA 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 687 492 98 CENIC-2152 - CENIC, US 2907 598 2152 459 SINET-AS Research Organization of Informa 36914 553 82 3 KENET-AS, KE 7497 465 212 24 CSTNET-AS-AP Computer Network Information 2018 374 318 69 TENET-1, ZA 680 291 1883 253 DFN Verein zur Foerderung eines Deutschen 2920 226 44 49 LACOE - Los Angeles County Office of Educ 786 210 1684 192 JANET Jisc Services Limited, GB 5786 197 16 1 UPRENET - University of Puerto Rico, PR 376 196 146 150 RISQ-AS - Reseau dInformations Scientifiq 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 553 550 KENET-AS, KE 7497 465 441 CSTNET-AS-AP Computer Network Information Cente 2018 374 305 TENET-1, ZA 5786 197 196 UPRENET - University of Puerto Rico, PR 58647 182 180 KAGAWAU-AS Kagawa University, JP 2920 226 177 LACOE - Los Angeles County Office of Education, 2907 598 139 SINET-AS Research Organization of Information a 18558 141 136 NETBLK-RCOEK - Riverside County Office of Educa 55824 151 131 NKN-CORE-NW NKN Core Network, IN 8895 98 93 ISU Internet Services Unit ISU, SA 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 - University 22272 UNALLOCATED 206.208.24.0/21 6325 ILLINOIS-CENTURY - Illi 401367 UNALLOCATED 216.186.25.0/24 10430 WA-K20 - Washington Sta Complete listing at https://bgp.nsrc.org/REN/ESnet/data-badAS Advertised Unallocated Addresses -------------------------------- Unassigned Network ASN Information AS Name 203.9.156.0/24 Origin: 1851 ADELAIDE-UNIVERSITY-AS-AP Adelaide Unive 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 /16:1862 /17:390 /18:427 /19:571 /20:766 /21:814 /22:1369 /23:1530 /24:10117 /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 529 553 KENET-AS, KE 8895 95 98 ISU Internet Services Unit ISU, SA 2152 84 687 CENIC-2152 - CENIC, US 31638 48 48 ASN-LEPIDA, IT 37215 39 45 MAREN, MW 200521 34 58 SEAP-AGE, ES 46115 32 35 LUTHER - Luther College, US 25977 30 44 HCCS - HOUSTON COMMUNITY COLLEGE SYSTEM, US 27609 29 45 USC-UNIVERSITY-HOSPITAL - USC-University Hospital, US 40326 29 33 ECKERD-COLLEGE - Eckerd College, US Complete listing at https://bgp.nsrc.org/REN/ESnet/data-sXXas-nos Number of /24s announced per /8 block (Global) ---------------------------------------------- 1:2 5:18 8:4 12:1 14:95 18:39 23:10 24:2 31:1 35:3 37:26 38:14 40:1 41:233 42:16 44:5 45:23 46:5 47:1 49:13 50:6 58:13 59:20 60:6 61:3 62:4 63:36 64:46 65:23 66:55 67:57 68:18 69:19 70:2 72:6 74:58 76:28 77:4 78:3 79:5 80:6 81:25 82:3 83:7 84:4 85:26 86:1 87:1 89:17 91:36 93:14 94:2 95:2 96:5 97:1 98:2 101:3 102:3 103:340 104:85 107:13 108:9 109:10 111:7 113:2 114:24 116:7 117:5 118:32 119:36 121:18 122:8 123:8 124:42 125:3 128:58 129:57 130:101 131:55 132:62 133:156 134:114 136:199 137:121 138:9 139:5 140:33 141:8 142:31 143:18 144:10 145:13 146:17 147:66 148:73 149:11 150:33 151:11 152:84 153:15 154:38 155:87 156:123 157:8 158:28 159:114 160:33 161:31 162:28 163:78 164:10 165:46 166:2 167:34 168:104 169:7 170:26 171:1 172:1 173:6 174:1 175:15 177:1 180:16 182:11 184:1 185:40 187:2 188:22 191:9 192:1402 193:294 194:101 195:86 196:149 197:344 198:572 199:249 200:2 202:599 203:417 204:415 205:179 206:204 207:354 208:38 209:162 210:224 211:5 212:135 213:4 216:95 217:22 218:19 219:6 220:16 222:4 223:6 End of report