IPv4 R&E Routing Table Report 22:20 GMT Tue 19 Aug, 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: 18695 Prefixes after maximum aggregation (per Origin AS): 10245 Deaggregation factor: 1.82 Unique aggregates announced (without unneeded subnets): 11390 Number of IPv4 prefixes with a valid ROA: 8005 Number of IPv4 prefixes with an invalid ROA: 1 Number of IPv4 prefixes with no ROA: 10689 Total ASes present in the Internet Routing Table: 2663 Prefixes per ASN: 7.02 Origin-only ASes present in the Internet Routing Table: 2323 Origin ASes announcing only one prefix: 1035 Transit ASes present in the Internet Routing Table: 340 Transit-only ASes present in the Internet Routing Table: 50 Paths with bogon ASNs present in the IPv4 Routing Table: 0 Average AS path length visible in the Internet Routing Table: 3.8 Max AS path length visible: 15 Max AS path prepend of ASN (395156) 12 Prefixes from unregistered ASNs in the Routing Table: 34 Number of instances of unregistered ASNs: 34 Number of 32-bit ASNs allocated by the RIRs: 47206 Number of 32-bit ASNs visible in the Routing Table: 659 Prefixes from 32-bit ASNs in the Routing Table: 1800 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: 166243584 Equivalent to 9 /8s, 232 /16s and 173 /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: 2230 APNIC Region Analysis Summary ----------------------------- Prefixes being announced by APNIC Region ASes: 4724 Total APNIC prefixes after maximum aggregation: 2304 APNIC Deaggregation factor: 2.05 Prefixes being announced from the APNIC address blocks: 4723 Unique aggregates announced from the APNIC address blocks: 2659 APNIC Region origin ASes present in the Internet Routing Table: 577 APNIC Prefixes per ASN: 8.19 APNIC Region origin ASes announcing only one prefix: 239 APNIC Region transit ASes present in the Internet Routing Table: 50 Average APNIC Region AS path length visible: 3.7 Max APNIC Region AS path length visible: 12 Number of APNIC region 32-bit ASNs visible in the Routing Table: 231 Number of APNIC addresses announced to Internet: 35687936 Equivalent to 2 /8s, 32 /16s and 142 /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: 8296 Total ARIN prefixes after maximum aggregation: 4611 ARIN Deaggregation factor: 1.80 Prefixes being announced from the ARIN address blocks: 8340 Unique aggregates announced from the ARIN address blocks: 5123 ARIN Region origin ASes present in the Internet Routing Table: 1272 ARIN Prefixes per ASN: 6.56 ARIN Region origin ASes announcing only one prefix: 452 ARIN Region transit ASes present in the Internet Routing Table: 153 Average ARIN Region AS path length visible: 3.8 Max ARIN Region AS path length visible: 15 Number of ARIN region 32-bit ASNs visible in the Routing Table: 226 Number of ARIN addresses announced to Internet: 72575744 Equivalent to 4 /8s, 83 /16s and 107 /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: 3538 Total RIPE prefixes after maximum aggregation: 2827 RIPE Deaggregation factor: 1.25 Prefixes being announced from the RIPE address blocks: 3529 Unique aggregates announced from the RIPE address blocks: 2907 RIPE Region origin ASes present in the Internet Routing Table: 656 RIPE Prefixes per ASN: 5.38 RIPE Region origin ASes announcing only one prefix: 295 RIPE Region transit ASes present in the Internet Routing Table: 102 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: 153 Number of RIPE addresses announced to Internet: 53217792 Equivalent to 3 /8s, 44 /16s and 10 /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: 949 Total LACNIC prefixes after maximum aggregation: 331 LACNIC Deaggregation factor: 2.87 Prefixes being announced from the LACNIC address blocks: 948 Unique aggregates announced from the LACNIC address blocks: 482 LACNIC Region origin ASes present in the Internet Routing Table: 58 LACNIC Prefixes per ASN: 16.34 LACNIC Region origin ASes announcing only one prefix: 22 LACNIC Region transit ASes present in the Internet Routing Table: 17 Average LACNIC Region AS path length visible: 4.2 Max LACNIC Region AS path length visible: 12 Number of LACNIC region 32-bit ASNs visible in the Routing Table: 20 Number of LACNIC addresses announced to Internet: 2367488 Equivalent to 0 /8s, 36 /16s and 32 /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: 1154 Total AfriNIC prefixes after maximum aggregation: 166 AfriNIC Deaggregation factor: 6.95 Prefixes being announced from the AfriNIC address blocks: 1153 Unique aggregates announced from the AfriNIC address blocks: 217 AfriNIC Region origin ASes present in the Internet Routing Table: 47 AfriNIC Prefixes per ASN: 24.53 AfriNIC Region origin ASes announcing only one prefix: 27 AfriNIC Region transit ASes present in the Internet Routing Table: 8 Average AfriNIC Region AS path length visible: 4.4 Max AfriNIC Region AS path length visible: 15 Number of AfriNIC region 32-bit ASNs visible in the Routing Table: 29 Number of AfriNIC addresses announced to Internet: 2392320 Equivalent to 0 /8s, 36 /16s and 129 /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 599 2169 461 SINET-AS Research Organization of Informa 7497 452 180 23 CSTNET-AS-AP Computer Network Information 1237 193 74 145 KREONET-AS-KR KISTI, KR 58647 182 18 2 KAGAWAU-AS Kagawa University, JP 7575 166 281 111 AARNET-AS-AP Australian Academic and Rese 4538 165 2403 80 ERX-CERNET-BKB China Education and Resear 55824 148 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 4621 59 35 8 UNINET-AS-AP UNINET-, TH 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 584 492 99 CENIC-2152, US 2920 231 44 49 LACOE, US 376 200 162 150 RISQ-AS, CA 5786 199 16 1 UPRENET, PR 18558 140 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 77 79 36 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 680 283 1883 250 DFN Verein zur Foerderung eines Deutschen 786 189 1742 184 JANET Jisc Services Limited, GB 559 114 533 104 SWITCH Switch, Swiss Academic and Researc 8895 109 24 5 ISU Internet Services Unit ISU, SA 1103 97 1247 83 SURFNET-NL SURFnet, The Netherlands, NL 2614 92 26 69 ROEDUNET, RO 137 82 677 77 ASGARR Consortium GARR, IT 3267 80 29 69 NIKS, RU 1930 78 88 73 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 233 171 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 1251 37 31 26 FUNDACAO DE AMPARO A PESQUISA DO ESTADO S 3596 37 8 4 Universidad Autonoma Metropolitana, MX 19611 37 16 1 Associacao Antonio Vieira - Unisinos, BR 20191 26 16 1 Pontificia Universidad Catolica de Chile, 278 25 32 4 Universidad Nacional Autonoma de Mexico, 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 565 82 3 KENET-AS, KE 2018 375 318 69 TENET-1, ZA 8094 47 48 18 PUKNET, ZA 37215 38 8 1 MAREN, MW 6879 24 2 9 ENSTINET-, EG 37501 11 49 6 UOFS, ZA 327700 11 16 1 MoRENet, MZ 37654 10 1 6 RwEdNet-AS, RW 36982 8 33 8 UCT, ZA 327947 7 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 2907 599 2169 461 SINET-AS Research Organization of Informa 2152 584 492 99 CENIC-2152, US 36914 565 82 3 KENET-AS, KE 7497 452 180 23 CSTNET-AS-AP Computer Network Information 2018 375 318 69 TENET-1, ZA 680 283 1883 250 DFN Verein zur Foerderung eines Deutschen 1916 233 171 41 Rede Nacional de Ensino e Pesquisa, BR 2920 231 44 49 LACOE, US 376 200 162 150 RISQ-AS, CA 5786 199 16 1 UPRENET, PR 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 565 562 KENET-AS, KE 2152 584 485 CENIC-2152, US 7497 452 429 CSTNET-AS-AP Computer Network Information Cente 2018 375 306 TENET-1, ZA 5786 199 198 UPRENET, PR 1916 233 192 Rede Nacional de Ensino e Pesquisa, BR 2920 231 182 LACOE, US 58647 182 180 KAGAWAU-AS Kagawa University, JP 18558 140 135 NETBLK-RCOEK, US 55824 148 127 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 /16:1911 /17:409 /18:435 /19:579 /20:815 /21:798 /22:1416 /23:1555 /24:10630 /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 541 565 KENET-AS, KE 8895 106 109 ISU Internet Services Unit ISU, SA 2152 67 584 CENIC-2152, US 3267 35 80 NIKS, RU 200521 33 57 SEAP-AGE, ES 37215 32 38 MAREN, MW 46115 32 35 LUTHER, US 25977 30 44 HCCS, US 27609 29 45 USC-UNIVERSITY-HOSPITAL, US 40326 29 33 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 5:16 8:5 12:2 14:92 18:39 23:11 24:3 31:1 35:4 37:14 38:13 40:1 41:223 42:18 44:5 45:35 46:5 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 74:52 76:27 77:9 78:3 79:9 80:13 81:27 82:5 83:8 84:4 85:47 86:3 87:1 89:9 91:41 92:2 93:14 94:2 95:2 96:5 97:1 98:2 101:3 102:11 103:341 104:74 107:2 108:8 109:7 111:21 113:1 114:21 116:7 117:61 118:33 119:31 121:28 122:8 123:8 124:42 125:5 128:59 129:47 130:98 131:67 132:68 133:156 134:109 136:200 137:106 138:11 139:5 140:32 141:4 142:26 143:25 144:37 145:2 146:137 147:27 148:201 149:11 150:36 151:12 152:95 153:15 154:40 155:84 156:129 157:5 158:26 159:117 160:31 161:29 162:29 163:70 164:9 165:43 166:2 167:28 168:96 169:6 170:25 171:1 172:1 173:6 174:1 175:16 177:1 179:7 180:16 181:1 182:12 184:1 185:50 186:2 187:7 188:16 190:17 191:9 192:1393 193:278 194:123 195:72 196:147 197:351 198:524 199:248 200:271 201:4 202:623 203:429 204:400 205:181 206:201 207:319 208:63 209:143 210:219 211:4 212:147 213:4 216:85 217:22 218:22 219:6 220:16 222:4 223:5 End of report