IPv4 R&E Routing Table Report 22:20 GMT Wed 17 Dec, 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: 18840 Prefixes after maximum aggregation (per Origin AS): 10223 Deaggregation factor: 1.84 Unique aggregates announced (without unneeded subnets): 11387 Number of IPv4 prefixes with a valid ROA: 7990 Number of IPv4 prefixes with an invalid ROA: 30 Number of IPv4 prefixes with no ROA: 10820 Total ASes present in the Internet Routing Table: 2656 Prefixes per ASN: 7.09 Origin-only ASes present in the Internet Routing Table: 2310 Origin ASes announcing only one prefix: 1036 Transit ASes present in the Internet Routing Table: 346 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: 3.9 Max AS path length visible: 16 Max AS path prepend of ASN (395156) 12 Prefixes from unregistered ASNs in the Routing Table: 12 Number of instances of unregistered ASNs: 12 Number of 32-bit ASNs allocated by the RIRs: 48221 Number of 32-bit ASNs visible in the Routing Table: 684 Prefixes from 32-bit ASNs in the Routing Table: 1894 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: 3 Number of addresses announced to Internet: 167056384 Equivalent to 9 /8s, 245 /16s and 20 /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: 2178 APNIC Region Analysis Summary ----------------------------- Prefixes being announced by APNIC Region ASes: 4609 Total APNIC prefixes after maximum aggregation: 2267 APNIC Deaggregation factor: 2.03 Prefixes being announced from the APNIC address blocks: 4608 Unique aggregates announced from the APNIC address blocks: 2546 APNIC Region origin ASes present in the Internet Routing Table: 574 APNIC Prefixes per ASN: 8.03 APNIC Region origin ASes announcing only one prefix: 237 APNIC Region transit ASes present in the Internet Routing Table: 50 Average APNIC Region AS path length visible: 3.6 Max APNIC Region AS path length visible: 12 Number of APNIC region 32-bit ASNs visible in the Routing Table: 230 Number of APNIC addresses announced to Internet: 35707136 Equivalent to 2 /8s, 32 /16s and 217 /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: 8458 Total ARIN prefixes after maximum aggregation: 4653 ARIN Deaggregation factor: 1.82 Prefixes being announced from the ARIN address blocks: 8479 Unique aggregates announced from the ARIN address blocks: 5194 ARIN Region origin ASes present in the Internet Routing Table: 1267 ARIN Prefixes per ASN: 6.69 ARIN Region origin ASes announcing only one prefix: 448 ARIN Region transit ASes present in the Internet Routing Table: 152 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: 225 Number of ARIN addresses announced to Internet: 72121344 Equivalent to 4 /8s, 76 /16s and 124 /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: 3302 Total RIPE prefixes after maximum aggregation: 2634 RIPE Deaggregation factor: 1.25 Prefixes being announced from the RIPE address blocks: 3293 Unique aggregates announced from the RIPE address blocks: 2726 RIPE Region origin ASes present in the Internet Routing Table: 601 RIPE Prefixes per ASN: 5.48 RIPE Region origin ASes announcing only one prefix: 278 RIPE Region transit ASes present in the Internet Routing Table: 101 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: 149 Number of RIPE addresses announced to Internet: 52938496 Equivalent to 3 /8s, 39 /16s and 199 /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: 1230 Total LACNIC prefixes after maximum aggregation: 462 LACNIC Deaggregation factor: 2.66 Prefixes being announced from the LACNIC address blocks: 1229 Unique aggregates announced from the LACNIC address blocks: 632 LACNIC Region origin ASes present in the Internet Routing Table: 117 LACNIC Prefixes per ASN: 10.50 LACNIC Region origin ASes announcing only one prefix: 46 LACNIC Region transit ASes present in the Internet Routing Table: 22 Average LACNIC Region AS path length visible: 4.4 Max LACNIC Region AS path length visible: 12 Number of LACNIC region 32-bit ASNs visible in the Routing Table: 52 Number of LACNIC addresses announced to Internet: 3792640 Equivalent to 0 /8s, 57 /16s and 223 /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: 1229 Total AfriNIC prefixes after maximum aggregation: 203 AfriNIC Deaggregation factor: 6.05 Prefixes being announced from the AfriNIC address blocks: 1228 Unique aggregates announced from the AfriNIC address blocks: 286 AfriNIC Region origin ASes present in the Internet Routing Table: 50 AfriNIC Prefixes per ASN: 24.56 AfriNIC Region origin ASes announcing only one prefix: 27 AfriNIC Region transit ASes present in the Internet Routing Table: 11 Average AfriNIC Region AS path length visible: 4.8 Max AfriNIC Region AS path length visible: 9 Number of AfriNIC region 32-bit ASNs visible in the Routing Table: 28 Number of AfriNIC addresses announced to Internet: 2494208 Equivalent to 0 /8s, 38 /16s and 15 /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 589 2168 460 SINET-AS Research Organization of Informa 7497 453 180 23 CSTNET-AS-AP Computer Network Information 1237 196 72 151 KREONET-AS-KR KISTI, KR 58647 182 18 2 KAGAWAU-AS Kagawa University, JP 4538 166 2403 80 ERX-CERNET-BKB China Education and Resear 7575 161 281 108 AARNET-AS-AP Australian Academic and Rese 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 659 492 99 CENIC-2152, US 2920 229 44 49 LACOE, US 376 200 162 150 RISQ-AS, CA 5786 198 16 1 UPRENET, PR 18558 139 18 5 NETBLK-RCOEK, US 81 117 455 35 NCREN, US 21976 88 34 14 NJEDGE-NET, US 237 84 542 49 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 786 208 1738 186 JANET Jisc Services Limited, GB 559 115 533 105 SWITCH Switch, Swiss Academic and Researc 8895 102 24 5 ISU Internet Services Unit ISU, SA 1103 98 1247 83 SURFNET-NL SURFnet, The Netherlands, NL 2614 88 26 68 ROEDUNET, RO 137 82 677 77 ASGARR Consortium GARR, IT 1930 77 88 72 RCCN Fundacao para a Ciencia e a Tecnolog 553 75 366 75 BELWUE BelWue-Koordination, DE 2200 65 630 60 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 1916 205 177 41 Rede Nacional de Ensino e Pesquisa, BR 28391 160 10 72 Universidad Juarez Autonoma de Tabasco, M 11340 111 25 50 Red Universitaria Nacional, CL 271640 68 8 1 UNIVERSIDADE FEDERAL DE VICOSA, BR 3596 66 8 4 Universidad Autonoma Metropolitana, MX 19611 53 17 2 Associacao Antonio Vieira - Unisinos, BR 61468 51 3 21 CEDIA, EC 2715 48 68 35 Fundacao Carlos Chagas Filho de Amparo a 1251 42 35 27 FUNDACAO DE AMPARO A PESQUISA DO ESTADO S 28614 38 2 2 Fundacao Universidade Regional de Blumena 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 564 82 3 KENET-AS, KE 2018 375 318 69 TENET-1, ZA 2561 68 4 34 EUN, EG 8094 47 48 18 PUKNET, ZA 37215 44 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 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 659 492 99 CENIC-2152, US 2907 589 2168 460 SINET-AS Research Organization of Informa 36914 564 82 3 KENET-AS, KE 7497 453 180 23 CSTNET-AS-AP Computer Network Information 2018 375 318 69 TENET-1, ZA 680 282 1883 249 DFN Verein zur Foerderung eines Deutschen 2920 229 44 49 LACOE, US 786 208 1738 186 JANET Jisc Services Limited, GB 1916 205 177 41 Rede Nacional de Ensino e Pesquisa, BR 376 200 162 150 RISQ-AS, CA 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 564 561 KENET-AS, KE 7497 453 430 CSTNET-AS-AP Computer Network Information Cente 2018 375 306 TENET-1, ZA 5786 198 197 UPRENET, PR 2920 229 180 LACOE, US 58647 182 180 KAGAWAU-AS Kagawa University, JP 1916 205 164 Rede Nacional de Ensino e Pesquisa, BR 18558 139 134 NETBLK-RCOEK, US 55824 151 131 NKN-CORE-NW NKN Core Network, IN 2907 589 129 SINET-AS Research Organization of Information a 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 64011 UNALLOCATED 130.215.0.0/16 10326 WPI, US 396334 UNALLOCATED 205.143.136.0/21 5078 ONENET-AS-1, US 396334 UNALLOCATED 205.143.136.0/24 5078 ONENET-AS-1, US 396334 UNALLOCATED 205.143.137.0/24 5078 ONENET-AS-1, US 396334 UNALLOCATED 205.143.138.0/24 5078 ONENET-AS-1, US 396334 UNALLOCATED 205.143.139.0/24 5078 ONENET-AS-1, US 396334 UNALLOCATED 205.143.140.0/24 5078 ONENET-AS-1, US 396334 UNALLOCATED 205.143.141.0/24 5078 ONENET-AS-1, US 396334 UNALLOCATED 205.143.142.0/24 5078 ONENET-AS-1, US Complete listing at https://bgp.nsrc.org/REN/ESnet/data-badAS Advertised Unallocated Addresses -------------------------------- Unassigned Network ASN Information AS Name 162.212.34.0/24 Origin: 54048 CVIN, US 162.212.34.0/24 Transit: 2152 CENIC-2152, US 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 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 /16:1915 /17:414 /18:443 /19:586 /20:829 /21:857 /22:1396 /23:1558 /24:10695 /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 540 564 KENET-AS, KE 8895 99 102 ISU Internet Services Unit ISU, SA 2152 73 659 CENIC-2152, US 31638 48 48 ASN-LEPIDA, IT 37215 38 44 MAREN, MW 200521 34 58 SEAP-AGE, ES 28614 32 38 Fundacao Universidade Regional de Blumenau, BR 46115 32 35 LUTHER, US 25977 30 44 HCCS, US 27609 29 45 USC-UNIVERSITY-HOSPITAL, 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 12:1 14:95 18:39 23:9 24:3 31:1 35:5 37:26 38:13 40:1 41:227 42:17 44:5 45:36 46:4 47:1 49:13 50:5 52:1 58:14 59:20 60:6 61:3 62:4 63:32 64:49 65:21 66:58 67:43 68:18 69:19 70:2 71:1 72:6 74:54 76:28 77:7 78:3 79:9 80:6 81:27 82:3 83:6 84:4 85:26 86:1 87:1 89:16 91:38 93:13 94:2 95:2 96:5 97:1 98:2 101:3 102:6 103:343 104:74 108:8 109:9 111:7 113:2 114:21 116:7 117:5 118:32 119:30 121:17 122:8 123:8 124:42 125:3 128:58 129:44 130:99 131:62 132:64 133:157 134:114 136:199 137:114 138:9 139:4 140:33 141:9 142:30 143:26 144:10 145:3 146:137 147:66 148:234 149:11 150:36 151:10 152:116 153:14 154:40 155:86 156:127 157:23 158:28 159:118 160:31 161:31 162:29 163:66 164:9 165:43 166:2 167:28 168:103 169:6 170:19 171:1 172:1 173:6 174:1 175:15 177:5 179:12 180:16 182:11 184:3 185:43 186:3 187:23 188:20 190:16 191:13 192:1401 193:292 194:94 195:87 196:148 197:351 198:554 199:250 200:295 201:20 202:586 203:431 204:408 205:181 206:200 207:349 208:38 209:149 210:222 211:4 212:137 213:4 216:88 217:22 218:19 219:5 220:16 222:4 223:6 End of report