IPv4 R&E Routing Table Report 22:20 GMT Wed 10 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: 18912 Prefixes after maximum aggregation (per Origin AS): 10430 Deaggregation factor: 1.81 Unique aggregates announced (without unneeded subnets): 11598 Number of IPv4 prefixes with a valid ROA: 7944 Number of IPv4 prefixes with an invalid ROA: 1 Number of IPv4 prefixes with no ROA: 10967 Total ASes present in the Internet Routing Table: 2716 Prefixes per ASN: 6.96 Origin-only ASes present in the Internet Routing Table: 2371 Origin ASes announcing only one prefix: 1059 Transit ASes present in the Internet Routing Table: 345 Transit-only ASes present in the Internet Routing Table: 46 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: 34 Number of instances of unregistered ASNs: 34 Number of 32-bit ASNs allocated by the RIRs: 47345 Number of 32-bit ASNs visible in the Routing Table: 693 Prefixes from 32-bit ASNs in the Routing Table: 1868 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: 167747584 Equivalent to 9 /8s, 255 /16s and 160 /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: 2212 APNIC Region Analysis Summary ----------------------------- Prefixes being announced by APNIC Region ASes: 4695 Total APNIC prefixes after maximum aggregation: 2302 APNIC Deaggregation factor: 2.04 Prefixes being announced from the APNIC address blocks: 4694 Unique aggregates announced from the APNIC address blocks: 2634 APNIC Region origin ASes present in the Internet Routing Table: 577 APNIC Prefixes per ASN: 8.14 APNIC Region origin ASes announcing only one prefix: 238 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: 13 Number of APNIC region 32-bit ASNs visible in the Routing Table: 230 Number of APNIC addresses announced to Internet: 35743488 Equivalent to 2 /8s, 33 /16s and 103 /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: 8376 Total ARIN prefixes after maximum aggregation: 4664 ARIN Deaggregation factor: 1.80 Prefixes being announced from the ARIN address blocks: 8420 Unique aggregates announced from the ARIN address blocks: 5188 ARIN Region origin ASes present in the Internet Routing Table: 1272 ARIN Prefixes per ASN: 6.62 ARIN Region origin ASes announcing only one prefix: 455 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: 226 Number of ARIN addresses announced to Internet: 72523264 Equivalent to 4 /8s, 82 /16s and 158 /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: 3435 Total RIPE prefixes after maximum aggregation: 2822 RIPE Deaggregation factor: 1.22 Prefixes being announced from the RIPE address blocks: 3426 Unique aggregates announced from the RIPE address blocks: 2919 RIPE Region origin ASes present in the Internet Routing Table: 648 RIPE Prefixes per ASN: 5.29 RIPE Region origin ASes announcing only one prefix: 292 RIPE Region transit ASes present in the Internet Routing Table: 101 Average RIPE Region AS path length visible: 3.8 Max RIPE Region AS path length visible: 13 Number of RIPE region 32-bit ASNs visible in the Routing Table: 152 Number of RIPE addresses announced to Internet: 53080064 Equivalent to 3 /8s, 41 /16s and 240 /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: 1202 Total LACNIC prefixes after maximum aggregation: 466 LACNIC Deaggregation factor: 2.58 Prefixes being announced from the LACNIC address blocks: 1201 Unique aggregates announced from the LACNIC address blocks: 633 LACNIC Region origin ASes present in the Internet Routing Table: 120 LACNIC Prefixes per ASN: 10.01 LACNIC Region origin ASes announcing only one prefix: 47 LACNIC Region transit ASes present in the Internet Routing Table: 22 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: 55 Number of LACNIC addresses announced to Internet: 3922688 Equivalent to 0 /8s, 59 /16s and 219 /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: 1170 Total AfriNIC prefixes after maximum aggregation: 170 AfriNIC Deaggregation factor: 6.88 Prefixes being announced from the AfriNIC address blocks: 1169 Unique aggregates announced from the AfriNIC address blocks: 222 AfriNIC Region origin ASes present in the Internet Routing Table: 50 AfriNIC Prefixes per ASN: 23.38 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: 4.7 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: 2475776 Equivalent to 0 /8s, 37 /16s and 199 /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 193 74 146 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 165 2403 80 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 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 598 492 99 CENIC-2152, US 2920 231 44 49 LACOE, US 376 200 162 150 RISQ-AS, CA 5786 198 16 1 UPRENET, PR 18558 139 18 5 NETBLK-RCOEK, US 81 127 471 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 680 282 1883 249 DFN Verein zur Foerderung eines Deutschen 786 189 1742 184 JANET Jisc Services Limited, GB 559 113 533 108 SWITCH Switch, Swiss Academic and Researc 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 77 88 72 RCCN Fundacao para a Ciencia e a Tecnolog 553 75 366 75 BELWUE BelWue-Koordination, DE 2200 64 630 59 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 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 374 318 69 TENET-1, ZA 8094 47 48 18 PUKNET, ZA 37215 39 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 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 598 492 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 374 318 69 TENET-1, ZA 680 282 1883 249 DFN Verein zur Foerderung eines Deutschen 2920 231 44 49 LACOE, US 1916 204 177 41 Rede Nacional de Ensino e Pesquisa, BR 376 200 162 150 RISQ-AS, CA 5786 198 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 575 572 KENET-AS, KE 7497 452 429 CSTNET-AS-AP Computer Network Information Cente 2018 374 305 TENET-1, ZA 5786 198 197 UPRENET, PR 2920 231 182 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 /16:1924 /17:417 /18:441 /19:586 /20:840 /21:829 /22:1455 /23:1576 /24:10697 /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 2152 73 598 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 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 8:5 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 46:5 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 69:16 70:2 71:1 72:8 74:54 76:27 77:9 78:3 79:9 80:13 81:27 82:5 83:8 84:6 85:48 86:3 87:1 89:15 91:38 92:2 93:14 94:2 95:2 96:5 97:1 98:2 101:3 102:11 103:339 104:74 107:2 108:8 109:6 111:5 113:1 114:21 116:7 117:61 118:33 119:31 121:12 122:8 123:8 124:42 125:5 128:59 129:47 130:97 131:69 132:65 133:156 134:111 136:199 137:106 138:11 139:5 140:33 141:4 142:27 143:25 144:45 145:2 146:137 147:51 148:201 149:11 150:36 151:12 152:124 153:14 154:40 155:87 156:129 157:23 158:26 159:117 160:32 161:29 162:30 163:70 164:9 165:43 166:2 167:28 168:102 169:6 170:26 171:1 172:1 173:6 174:1 175:16 177:4 179:13 180:16 181:1 182:12 184:1 185:49 186:3 187:23 188:21 190:17 191:13 192:1394 193:278 194:122 195:71 196:148 197:358 198:523 199:243 200:293 201:20 202:625 203:430 204:398 205:184 206:198 207:321 208:63 209:149 210:219 211:4 212:44 213:4 216:88 217:23 218:22 219:6 220:16 222:4 223:5 End of report