{"id":3420,"date":"2026-10-27T12:31:21","date_gmt":"2026-10-27T19:31:21","guid":{"rendered":"https:\/\/cyber.mag212.com\/learn\/ospf-cheat-sheet\/"},"modified":"2026-10-27T12:31:21","modified_gmt":"2026-10-27T19:31:21","slug":"ospf-cheat-sheet","status":"publish","type":"page","link":"https:\/\/cyber.mag212.com\/fr\/learn\/ospf-cheat-sheet\/","title":{"rendered":"Aide-m\u00e9moire OSPF"},"content":{"rendered":"<style>.m212os{--bg:#07111C;--panel:#122538;--green:#46DB82;--cyan:#3CC8E8;--red:#F25C5C;--ink:#E7F1FB;background:var(--bg);color:var(--ink);font:16px\/1.65 system-ui,Arial,sans-serif;border:1px solid #1f3b4d;border-radius:14px;padding:28px 24px}\n.m212os *{box-sizing:border-box}\n.m212os .os-hero{border-bottom:2px solid var(--green);padding-bottom:22px}\n.m212os .os-brand{font-size:1.4rem;font-weight:900;letter-spacing:.14em;color:var(--ink)}.m212os .os-brand span{color:var(--green)}\n.m212os .os-title{font-size:clamp(2rem,5vw,3.4rem);line-height:1.12;margin:13px 0 8px;color:#fff;border:0;padding:0}\n.m212os h2{color:var(--green);border-bottom:1px solid #24425b;padding-bottom:9px;margin:33px 0 12px;font-size:26px}\n.m212os h3{color:var(--cyan);margin:22px 0 8px}\n.m212os p{color:#CADAE8;margin:0 0 12px}\n.m212os figure{margin:28px 0;background:#091b2a;border:1px solid #28637c;border-radius:16px;overflow:hidden}\n.m212os figure svg{display:block;width:100%;height:auto}\n.m212os figcaption{padding:12px;color:#B4C8D5;font-size:.88rem}\n.m212os .grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:14px}\n.m212os .card{border:1px solid #24526a;background:var(--panel);border-radius:12px;padding:16px}\n.m212os .card p{margin:6px 0 0}\n.m212os .code{white-space:pre;overflow:auto;background:#081b28;color:#BAF0DF;border:1px solid #27617a;padding:20px;border-radius:12px;font:13px\/1.55 ui-monospace,SFMono-Regular,Consolas,monospace;margin:8px 0 14px}\n.m212os code{color:#9cebd3;font-family:ui-monospace,Consolas,monospace;background:#0a1a29;border-radius:4px;padding:1px 4px}\n.m212os .qa{background:#10293a;padding:12px 18px;border-left:3px solid var(--green);margin:10px 0;border-radius:5px}\n.m212os .qa p{margin:4px 0 0}\n.m212os a{color:var(--cyan)}\n.m212os .os-foot{border-top:1px solid #246;text-align:center;padding:26px 10px 4px;color:#9fb7c8;margin-top:30px;font-size:14px}\n.m212os .os-dl{display:inline-block;margin-top:10px;background:#46db82;color:#04130c;font-weight:800;text-decoration:none;border-radius:8px;padding:11px 18px}\n@media(max-width:620px){.m212os{padding:16px 12px}.m212os .code{font-size:12px;padding:14px}}<\/style>\n<div class=\"m212os\" id=\"m212-ospf\"><div class=\"os-hero\"><div class=\"os-brand\">MAG212 <span>CYBER<\/span><\/div><h2 class=\"os-title\">Aide-m\u00e9moire OSPF ultime<\/h2><p>Configuration \u2022 Commandes \u2022 Routage multi-zones \u2022 D\u00e9pannage \u2022 S\u00e9curit\u00e9<\/p><a class=\"os-dl\" href=\"https:\/\/cyber.mag212.com\/wp-content\/uploads\/2026\/10\/MAG212_CYBER_OSPF_Ultimate_Cheat_Sheet.pdf\" target=\"_blank\" rel=\"noopener\">\u2b07 T\u00e9l\u00e9charger l&#039;\u00e9dition PDF<\/a><\/div><figure><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 1800 1090\" role=\"img\" aria-labelledby=\"osT osD\"><title id=\"osT\">OSPF five-router multi-area lab topology<\/title><desc id=\"osD\">R1, R2 et R3 forment le r\u00e9seau dorsal de la zone 0, avec une liaison de secours entre R1 et R3. R1 est le routeur de bordure de zone (ABR) pour les zones 10 et R4\u00a0; R3 est l\u2019ABR pour les zones 20 et R5. R2 connecte \u00e9galement un segment de diffusion VLAN 100 utilis\u00e9 pour illustrer l\u2019\u00e9lection du routeur d\u00e9sign\u00e9 (DR) et du routeur d\u00e9sign\u00e9 de secours (BDR).<\/desc><defs><lineargradient id=\"osbg\" x2=\"1\" y2=\"1\"><stop stop-color=\"#05121e\"\/><stop offset=\"1\" stop-color=\"#0f2a3d\"\/><\/lineargradient><lineargradient id=\"osrt\" x2=\"0\" y2=\"1\"><stop stop-color=\"#5ca6c5\"\/><stop offset=\"1\" stop-color=\"#126181\"\/><\/lineargradient><\/defs><rect width=\"1800\" height=\"1090\" fill=\"url(#osbg)\"\/><g stroke=\"#1f3d52\" opacity=\".45\"><path d=\"M0 0V1090\"\/><path d=\"M50 0V1090\"\/><path d=\"M100 0V1090\"\/><path d=\"M150 0V1090\"\/><path d=\"M200 0V1090\"\/><path d=\"M250 0V1090\"\/><path d=\"M300 0V1090\"\/><path d=\"M350 0V1090\"\/><path d=\"M400 0V1090\"\/><path d=\"M450 0V1090\"\/><path d=\"M500 0V1090\"\/><path d=\"M550 0V1090\"\/><path d=\"M600 0V1090\"\/><path d=\"M650 0V1090\"\/><path d=\"M700 0V1090\"\/><path d=\"M750 0V1090\"\/><path d=\"M800 0V1090\"\/><path d=\"M850 0V1090\"\/><path d=\"M900 0V1090\"\/><path d=\"M950 0V1090\"\/><path d=\"M1000 0V1090\"\/><path d=\"M1050 0V1090\"\/><path d=\"M1100 0V1090\"\/><path d=\"M1150 0V1090\"\/><path d=\"M1200 0V1090\"\/><path d=\"M1250 0V1090\"\/><path d=\"M1300 0V1090\"\/><path d=\"M1350 0V1090\"\/><path d=\"M1400 0V1090\"\/><path d=\"M1450 0V1090\"\/><path d=\"M1500 0V1090\"\/><path d=\"M1550 0V1090\"\/><path d=\"M1600 0V1090\"\/><path d=\"M1650 0V1090\"\/><path d=\"M1700 0V1090\"\/><path d=\"M1750 0V1090\"\/><path d=\"M1800 0V1090\"\/><path d=\"M0 0H1800\"\/><path d=\"M0 50H1800\"\/><path d=\"M0 100H1800\"\/><path d=\"M0 150H1800\"\/><path d=\"M0 200H1800\"\/><path d=\"M0 250H1800\"\/><path d=\"M0 300H1800\"\/><path d=\"M0 350H1800\"\/><path d=\"M0 400H1800\"\/><path d=\"M0 450H1800\"\/><path d=\"M0 500H1800\"\/><path d=\"M0 550H1800\"\/><path d=\"M0 600H1800\"\/><path d=\"M0 650H1800\"\/><path d=\"M0 700H1800\"\/><path d=\"M0 750H1800\"\/><path d=\"M0 800H1800\"\/><path d=\"M0 850H1800\"\/><path d=\"M0 900H1800\"\/><path d=\"M0 950H1800\"\/><path d=\"M0 1000H1800\"\/><path d=\"M0 1050H1800\"\/><\/g><text x=\"60\" y=\"70\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"42\" font-weight=\"900\" fill=\"#46db82\">MAG212 CYBER<\/text><text x=\"460\" y=\"70\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"34\" font-weight=\"800\" fill=\"#e3f4fc\">\u00b7 TOPOLOGIE DE LABORATOIRE MULTI-ZONES OSPF<\/text><text x=\"62\" y=\"106\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"20\" fill=\"#9cc3d9\">Processus OSPFv2 100 \u00b7 Liaisons point \u00e0 point \/30 \u00b7 Cisco IOS XE \u00b7 Adressage de laboratoire uniquement<\/text><rect x=\"50\" y=\"135\" width=\"1700\" height=\"465\" rx=\"24\" fill=\"#0b2335\" fill-opacity=\".7\" stroke=\"#3cc8e8\" stroke-width=\"3\" stroke-dasharray=\"14 9\"\/><text x=\"80\" y=\"178\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"28\" font-weight=\"800\" fill=\"#3cc8e8\">ZONE 0 \u00b7 COLONNE VERT\u00c9BRALE<\/text><rect x=\"50\" y=\"650\" width=\"800\" height=\"345\" rx=\"24\" fill=\"#0b2a22\" fill-opacity=\".6\" stroke=\"#46db82\" stroke-width=\"3\" stroke-dasharray=\"14 9\"\/><text x=\"80\" y=\"693\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"28\" font-weight=\"800\" fill=\"#46db82\">ZONE 10 \u00b7 SUCCURSALE<\/text><rect x=\"950\" y=\"650\" width=\"800\" height=\"345\" rx=\"24\" fill=\"#2a2414\" fill-opacity=\".45\" stroke=\"#f6b544\" stroke-width=\"3\" stroke-dasharray=\"14 9\"\/><text x=\"1720\" y=\"693\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"28\" font-weight=\"800\" fill=\"#f6b544\" text-anchor=\"end\">ZONE 20 \u00b7 SUCCURSALE<\/text><path d=\"M440 296V230H1360V296\" fill=\"none\" stroke=\"#f6a54a\" stroke-width=\"7\" stroke-dasharray=\"20 12\" stroke-linejoin=\"round\"\/><rect x=\"743.5\" y=\"200\" width=\"313\" height=\"62\" rx=\"9\" fill=\"#0a1f2f\" stroke=\"#8a6a3a\"\/><text x=\"900.0\" y=\"227\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"17\" font-weight=\"700\" fill=\"#ffe2bf\" text-anchor=\"middle\">Zone de sauvegarde 0 \u00b7 10.0.13.0\/30<\/text><text x=\"900.0\" y=\"253\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"17\" font-weight=\"400\" fill=\"#a9c7d8\" text-anchor=\"middle\">R1 Gi0\/0\/2 \u2194 R3 Gi0\/0\/2<\/text><path d=\"M502 340H838\" stroke=\"#3cc8e8\" stroke-width=\"10\" stroke-linecap=\"round\"\/><rect x=\"539.0\" y=\"308\" width=\"262\" height=\"62\" rx=\"9\" fill=\"#0a1f2f\" stroke=\"#3d6a84\"\/><text x=\"670.0\" y=\"335\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"17\" font-weight=\"700\" fill=\"#d7f2ff\" text-anchor=\"middle\">10.0.12.0\/30<\/text><text x=\"670.0\" y=\"361\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"17\" font-weight=\"400\" fill=\"#a9c7d8\" text-anchor=\"middle\">R1 Gi0\/0\/0 \u2194 R2 Gi0\/0\/0<\/text><path d=\"M962 340H1298\" stroke=\"#3cc8e8\" stroke-width=\"10\" stroke-linecap=\"round\"\/><rect x=\"999.0\" y=\"308\" width=\"262\" height=\"62\" rx=\"9\" fill=\"#0a1f2f\" stroke=\"#3d6a84\"\/><text x=\"1130.0\" y=\"335\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"17\" font-weight=\"700\" fill=\"#d7f2ff\" text-anchor=\"middle\">10.0.23.0\/30<\/text><text x=\"1130.0\" y=\"361\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"17\" font-weight=\"400\" fill=\"#a9c7d8\" text-anchor=\"middle\">R2 Gi0\/0\/1 \u2194 R3 Gi0\/0\/0<\/text><path d=\"M440 384V756\" stroke=\"#46db82\" stroke-width=\"10\" stroke-linecap=\"round\"\/><path d=\"M1360 384V756\" stroke=\"#f6b544\" stroke-width=\"10\" stroke-linecap=\"round\"\/><rect x=\"462\" y=\"598\" width=\"262\" height=\"62\" rx=\"9\" fill=\"#0a1f2f\" stroke=\"#2f7d58\"\/><text x=\"593.0\" y=\"625\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"17\" font-weight=\"700\" fill=\"#bff5d6\" text-anchor=\"middle\">Zone 10 \u00b7 10.0.14.0\/30<\/text><text x=\"593.0\" y=\"651\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"17\" font-weight=\"400\" fill=\"#a9c7d8\" text-anchor=\"middle\">R1 Gi0\/0\/1 \u2194 R4 Gi0\/0\/0<\/text><rect x=\"1076\" y=\"598\" width=\"262\" height=\"62\" rx=\"9\" fill=\"#0a1f2f\" stroke=\"#8a6a3a\"\/><text x=\"1207.0\" y=\"625\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"17\" font-weight=\"700\" fill=\"#ffe2bf\" text-anchor=\"middle\">Zone 20 \u00b7 10.0.35.0\/30<\/text><text x=\"1207.0\" y=\"651\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"17\" font-weight=\"400\" fill=\"#a9c7d8\" text-anchor=\"middle\">R3 Gi0\/0\/1 \u2194 R5 Gi0\/0\/0<\/text><path d=\"M900 384V478\" stroke=\"#9fe6ff\" stroke-width=\"6\"\/><path d=\"M832 480h96l20 22h-96z\" fill=\"#2c7ea2\" stroke=\"#9fe6ff\" stroke-width=\"2.5\"\/><rect x=\"852\" y=\"502\" width=\"96\" height=\"30\" fill=\"#155a78\" stroke=\"#9fe6ff\" stroke-width=\"2.5\"\/><rect x=\"860\" y=\"514\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"875\" y=\"514\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"890\" y=\"514\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"905\" y=\"514\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"920\" y=\"514\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"935\" y=\"514\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><text x=\"980\" y=\"505\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"18\" font-weight=\"700\" fill=\"#e3f4fc\">VLAN 100 \u00b7 10.0.100.0\/24<\/text><text x=\"980\" y=\"530\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"16\" fill=\"#a9c7d8\">Segment de diffusion \u00b7 D\u00e9mo DR\/BDR<\/text><text x=\"980\" y=\"553\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"16\" fill=\"#a9c7d8\">Priorit\u00e9 R2\u00a0: 200 \u00b7 VLAN 100\u00a0: 10.0.100.1<\/text><ellipse cx=\"440\" cy=\"360\" rx=\"60\" ry=\"22\" fill=\"#0d3a50\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><rect x=\"380\" y=\"320\" width=\"120\" height=\"40\" fill=\"url(#osrt)\"\/><path d=\"M380 320V360M500 320V360\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><ellipse cx=\"440\" cy=\"320\" rx=\"60\" ry=\"22\" fill=\"#4f9dbd\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><g stroke=\"#effaff\" stroke-width=\"3\" fill=\"none\" stroke-linecap=\"round\"><path d=\"M406 314h22m-6 -5l6 5l-6 5\"\/><path d=\"M452 314h22m-6 -5l6 5l-6 5\"\/><path d=\"M430 328h20m-6 -5l6 5l-6 5\"\/><\/g><text x=\"362\" y=\"332\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"32\" font-weight=\"800\" fill=\"#fff\" text-anchor=\"end\">R1<\/text><text x=\"362\" y=\"358\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"18\" fill=\"#cfe4ef\" text-anchor=\"end\">ABR \u00b7 Zone 0\/10<\/text><text x=\"362\" y=\"382\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"16\" fill=\"#8fb3c6\" text-anchor=\"end\">RID 1.1.1.1<\/text><ellipse cx=\"900\" cy=\"360\" rx=\"60\" ry=\"22\" fill=\"#0d3a50\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><rect x=\"840\" y=\"320\" width=\"120\" height=\"40\" fill=\"url(#osrt)\"\/><path d=\"M840 320V360M960 320V360\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><ellipse cx=\"900\" cy=\"320\" rx=\"60\" ry=\"22\" fill=\"#4f9dbd\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><g stroke=\"#effaff\" stroke-width=\"3\" fill=\"none\" stroke-linecap=\"round\"><path d=\"M866 314h22m-6 -5l6 5l-6 5\"\/><path d=\"M912 314h22m-6 -5l6 5l-6 5\"\/><path d=\"M890 328h20m-6 -5l6 5l-6 5\"\/><\/g><text x=\"924\" y=\"420\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"32\" font-weight=\"800\" fill=\"#fff\" text-anchor=\"start\">R2<\/text><text x=\"924\" y=\"446\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"18\" fill=\"#cfe4ef\" text-anchor=\"start\">Noyau \u00b7 Zone 0<\/text><text x=\"924\" y=\"470\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"16\" fill=\"#8fb3c6\" text-anchor=\"start\">RID 2.2.2.2<\/text><ellipse cx=\"1360\" cy=\"360\" rx=\"60\" ry=\"22\" fill=\"#0d3a50\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><rect x=\"1300\" y=\"320\" width=\"120\" height=\"40\" fill=\"url(#osrt)\"\/><path d=\"M1300 320V360M1420 320V360\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><ellipse cx=\"1360\" cy=\"320\" rx=\"60\" ry=\"22\" fill=\"#4f9dbd\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><g stroke=\"#effaff\" stroke-width=\"3\" fill=\"none\" stroke-linecap=\"round\"><path d=\"M1326 314h22m-6 -5l6 5l-6 5\"\/><path d=\"M1372 314h22m-6 -5l6 5l-6 5\"\/><path d=\"M1350 328h20m-6 -5l6 5l-6 5\"\/><\/g><text x=\"1438\" y=\"332\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"32\" font-weight=\"800\" fill=\"#fff\" text-anchor=\"start\">R3<\/text><text x=\"1438\" y=\"358\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"18\" fill=\"#cfe4ef\" text-anchor=\"start\">ABR \u00b7 Zone 0\/20<\/text><text x=\"1438\" y=\"382\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"16\" fill=\"#8fb3c6\" text-anchor=\"start\">RID 3.3.3.3<\/text><ellipse cx=\"440\" cy=\"820\" rx=\"60\" ry=\"22\" fill=\"#0d3a50\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><rect x=\"380\" y=\"780\" width=\"120\" height=\"40\" fill=\"url(#osrt)\"\/><path d=\"M380 780V820M500 780V820\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><ellipse cx=\"440\" cy=\"780\" rx=\"60\" ry=\"22\" fill=\"#4f9dbd\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><g stroke=\"#effaff\" stroke-width=\"3\" fill=\"none\" stroke-linecap=\"round\"><path d=\"M406 774h22m-6 -5l6 5l-6 5\"\/><path d=\"M452 774h22m-6 -5l6 5l-6 5\"\/><path d=\"M430 788h20m-6 -5l6 5l-6 5\"\/><\/g><text x=\"518\" y=\"792\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"32\" font-weight=\"800\" fill=\"#fff\" text-anchor=\"start\">R4<\/text><text x=\"518\" y=\"818\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"18\" fill=\"#cfe4ef\" text-anchor=\"start\">Routeur de zone 10<\/text><text x=\"518\" y=\"842\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"16\" fill=\"#8fb3c6\" text-anchor=\"start\">RID 4.4.4.4<\/text><ellipse cx=\"1360\" cy=\"820\" rx=\"60\" ry=\"22\" fill=\"#0d3a50\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><rect x=\"1300\" y=\"780\" width=\"120\" height=\"40\" fill=\"url(#osrt)\"\/><path d=\"M1300 780V820M1420 780V820\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><ellipse cx=\"1360\" cy=\"780\" rx=\"60\" ry=\"22\" fill=\"#4f9dbd\" stroke=\"#9fe6ff\" stroke-width=\"3\"\/><g stroke=\"#effaff\" stroke-width=\"3\" fill=\"none\" stroke-linecap=\"round\"><path d=\"M1326 774h22m-6 -5l6 5l-6 5\"\/><path d=\"M1372 774h22m-6 -5l6 5l-6 5\"\/><path d=\"M1350 788h20m-6 -5l6 5l-6 5\"\/><\/g><text x=\"1282\" y=\"792\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"32\" font-weight=\"800\" fill=\"#fff\" text-anchor=\"end\">R5<\/text><text x=\"1282\" y=\"818\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"18\" fill=\"#cfe4ef\" text-anchor=\"end\">Routeur de zone 20<\/text><text x=\"1282\" y=\"842\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"16\" fill=\"#8fb3c6\" text-anchor=\"end\">RID 5.5.5.5<\/text><path d=\"M440 844V892\" stroke=\"#46db82\" stroke-width=\"6\"\/><path d=\"M372 894h96l20 22h-96z\" fill=\"#2c7ea2\" stroke=\"#9fe6ff\" stroke-width=\"2.5\"\/><rect x=\"392\" y=\"916\" width=\"96\" height=\"30\" fill=\"#155a78\" stroke=\"#9fe6ff\" stroke-width=\"2.5\"\/><rect x=\"400\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"415\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"430\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"445\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"460\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"475\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><text x=\"518\" y=\"922\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"18\" font-weight=\"700\" fill=\"#e3f4fc\" text-anchor=\"start\">R\u00e9seau local des utilisateurs \u00b7 192.168.10.0\/24<\/text><text x=\"518\" y=\"946\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"16\" fill=\"#a9c7d8\" text-anchor=\"start\">Gi0\/0\/1 \u00b7 interface passive<\/text><path d=\"M1360 844V892\" stroke=\"#f6b544\" stroke-width=\"6\"\/><path d=\"M1292 894h96l20 22h-96z\" fill=\"#2c7ea2\" stroke=\"#9fe6ff\" stroke-width=\"2.5\"\/><rect x=\"1312\" y=\"916\" width=\"96\" height=\"30\" fill=\"#155a78\" stroke=\"#9fe6ff\" stroke-width=\"2.5\"\/><rect x=\"1320\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"1335\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"1350\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"1365\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"1380\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><rect x=\"1395\" y=\"928\" width=\"9\" height=\"6\" fill=\"#46db82\"\/><text x=\"1282\" y=\"922\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"18\" font-weight=\"700\" fill=\"#e3f4fc\" text-anchor=\"end\">R\u00e9seau local des utilisateurs \u00b7 192.168.20.0\/24<\/text><text x=\"1282\" y=\"946\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"16\" fill=\"#a9c7d8\" text-anchor=\"end\">Gi0\/0\/1 \u00b7 interface passive<\/text><path d=\"M50 1041h70\" stroke=\"#3cc8e8\" stroke-width=\"8\" stroke-linecap=\"round\"\/><text x=\"140\" y=\"1048\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"20\" font-weight=\"600\" fill=\"#d7e8f3\">Liaison point \u00e0 point de la zone 0<\/text><path d=\"M500 1041h70\" stroke=\"#f6a54a\" stroke-width=\"8\" stroke-linecap=\"round\" stroke-dasharray=\"20 12\"\/><text x=\"590\" y=\"1048\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"20\" font-weight=\"600\" fill=\"#d7e8f3\">Lien vers la zone de sauvegarde 0<\/text><path d=\"M890 1041h70\" stroke=\"#46db82\" stroke-width=\"8\" stroke-linecap=\"round\"\/><text x=\"980\" y=\"1048\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"20\" font-weight=\"600\" fill=\"#d7e8f3\">Liaison montante de la zone 10<\/text><path d=\"M1240 1041h70\" stroke=\"#f6b544\" stroke-width=\"8\" stroke-linecap=\"round\"\/><text x=\"1330\" y=\"1048\" font-family=\"DejaVu Sans,Arial,sans-serif\" font-size=\"20\" font-weight=\"600\" fill=\"#d7e8f3\">Liaison montante de la zone 20<\/text><\/svg><figcaption>Laboratoire original \u00e0 cinq routeurs\u00a0: R1\u2013R2\u2013R3 forment la zone 0 avec une liaison de secours R1\u2013R3\u00a0; R1 et R3 sont des ABR pour les zones 10 et 20. Les noms d\u2019interface, les sous-r\u00e9seaux et les ID de routeur correspondent aux configurations de la section 12.<\/figcaption><\/figure><div class=\"os-sec\"><h2>1. OSPF en bref<\/h2><p>OSPFv2 (Open Shortest Path First) est un protocole de routage interne \u00e0 \u00e9tat de liens. Les routeurs diffusent les informations d&#039;\u00e9tat de liens au sein de leur zone, construisent une base de donn\u00e9es d&#039;\u00e9tat de liens (LSDB) et ex\u00e9cutent l&#039;algorithme SPF (Dijkstra) pour s\u00e9lectionner les routes. Il utilise le protocole IP n\u00b0\u00a089, et non le port TCP\/UDP n\u00b0\u00a089. La distance administrative Cisco par d\u00e9faut est de 110\u00a0; l&#039;adresse multicast 224.0.0.5 atteint tous les routeurs SPF et l&#039;adresse 224.0.0.6 cible les routeurs d\u00e9sign\u00e9s (DR) et les routeurs de secours (BDR) sur les r\u00e9seaux de diffusion.<\/p><\/div><div class=\"os-sec\"><h2>2. Comprendre le laboratoire d&#039;entreprise \u00e0 cinq routeurs<\/h2><p>R1, R2 et R3 forment la zone dorsale 0. R1 connecte la zone 10 \u00e0 R4\u00a0; R3 connecte la zone 20 \u00e0 R5. La liaison R1\u2013R3 offre un chemin dorsal alternatif. Toutes les liaisons num\u00e9rot\u00e9es \/30 sont point \u00e0 point, sans \u00e9lection de routeur d\u00e9sign\u00e9 (DR) ni de routeur d\u00e9sign\u00e9 de secours (BDR). Le VLAN 100 sur le segment de diffusion dorsal partag\u00e9 illustre un cas o\u00f9 le DR\/BDR s&#039;applique si deux routeurs OSPF ou plus le partagent. R1 et R3 sont des routeurs de bordure de r\u00e9seau (ABR). Les interfaces de bouclage garantissent des identifiants de routeur stables. Ce sch\u00e9ma est conceptuel\u00a0: ajoutez un routeur compatible OSPF au VLAN 100 pour un environnement de test DR\/BDR multi-routeurs.<\/p><\/div><div class=\"os-sec\"><h2>3. Informations essentielles et minuteurs<\/h2><p>Les temporisateurs hello\/dead OSPFv2 typiques pour la diffusion Ethernet sont de 10\/40 secondes, selon la plateforme et le type de r\u00e9seau. Sur une liaison Ethernet point \u00e0 point, utilisez <code data-no-translation=\"\">ip ospf network point-to-point<\/code> Pour \u00e9viter l&#039;\u00e9lection du routeur d\u00e9sign\u00e9 (DR), les identifiants des routeurs doivent \u00eatre uniques\u00a0; les zones g\u00e9ographiques doivent correspondre chez les voisins\u00a0; l&#039;authentification et la compatibilit\u00e9 des intervalles Hello\/Dead sont essentielles. Les diff\u00e9rences de MTU IP entra\u00eenent souvent des probl\u00e8mes d&#039;adjacence lors des \u00e9changes de bases de donn\u00e9es. Sur les r\u00e9seaux multi-acc\u00e8s, une communication bidirectionnelle peut \u00eatre normale entre deux routeurs DROTHER.<\/p><\/div><div class=\"os-sec\"><h2>4. \u00c9tats voisins<\/h2><p>D\u00e9connexion \u2192 Initialisation \u2192 Communication bidirectionnelle \u2192 D\u00e9marrage \u2192 \u00c9change \u2192 Chargement \u2192 Plein. Une tentative peut appara\u00eetre sur les voisins NBMA configur\u00e9s manuellement. Le d\u00e9marrage n\u00e9gocie la relation ma\u00eetre\/esclave et l&#039;ordre des blocs de donn\u00e9es (DBD)\u00a0; l&#039;\u00e9change partage les r\u00e9sum\u00e9s DBD\u00a0; le chargement demande les LSA manquants. Sur les liaisons point \u00e0 point, l&#039;\u00e9tat stable attendu est FULL\/-. En diffusion, l&#039;\u00e9tat FULL\/DR, FULL\/BDR ou FULL\/DROTHER d\u00e9pend de l&#039;\u00e9lection\u00a0; la communication bidirectionnelle peut \u00eatre normale entre les DROTHERs.<\/p><\/div><div class=\"os-sec\"><h2>5. Les LSA que vous devez reconna\u00eetre<\/h2><p>Routeur de type 1\u00a0: g\u00e9n\u00e9r\u00e9 par chaque routeur et limit\u00e9 \u00e0 sa zone. R\u00e9seau de type 2\u00a0: g\u00e9n\u00e9r\u00e9 par le DR pour un r\u00e9seau de transit de diffusion. R\u00e9sum\u00e9 de type 3\u00a0: l\u2019ABR distribue les pr\u00e9fixes inter-zones. R\u00e9sum\u00e9 ASBR de type 4\u00a0: assure la connectivit\u00e9 \u00e0 un ASBR en cas de besoin. Route externe AS de type 5\u00a0: routes externes, sauf l\u00e0 o\u00f9 elles sont interdites (par exemple, les zones stub). Route externe NSSA de type 7\u00a0: introduite au sein d\u2019une NSSA, les routes \u00e9ligibles \u00e9tant traduites par l\u2019ABR en type 5. OSPFv3 utilise des LSA et des champs d\u2019en-t\u00eate diff\u00e9rents\u00a0; les sch\u00e9mas de paquets OSPFv2 ne doivent pas \u00eatre r\u00e9utilis\u00e9s pour OSPFv3.<\/p><\/div><div class=\"os-sec\"><h2>6. Conception des zones et types d&#039;itin\u00e9raires<\/h2><p>La zone dorsale 0 interconnecte les autres zones. Les zones standard acceptent les routes externes normales. Les zones stub bloquent les LSA externes de type 5 et utilisent une route par d\u00e9faut fournie par l&#039;ABR\u00a0; les zones totalement stub sont une extension Cisco r\u00e9duisant le nombre de LSA de synth\u00e8se. La NSSA autorise la redistribution externe via des LSA de type 7. Dans la table de routage\u00a0: O = intra-zone, O IA = inter-zone, O E1\/E2 = externe, O N1\/N2 = externe NSSA. E1 combine le co\u00fbt interne pour l&#039;ASBR et la m\u00e9trique externe\u00a0; E2 compare g\u00e9n\u00e9ralement la m\u00e9trique externe en premier.<\/p><\/div><div class=\"os-sec\"><h2>7. Co\u00fbt du trajet, DR\/BDR et redondance<\/h2><p>Le co\u00fbt OSPF est configurable via <code data-no-translation=\"\">ip ospf cost VALUE<\/code>, ou calcul\u00e9e \u00e0 partir d&#039;une bande passante de r\u00e9f\u00e9rence divis\u00e9e par la bande passante de l&#039;interface (entier minimum 1). D\u00e9finir la m\u00eame <code data-no-translation=\"\">auto-cost reference-bandwidth<\/code> Sur tous les routeurs, par exemple 100\u00a0000\u00a0Mbits\/s pour les liaisons 100\u00a0Gbit\/s. Sur un segment de diffusion, la priorit\u00e9 de l&#039;interface OSPF \u00e9ligible la plus \u00e9lev\u00e9e devient DR, puis BDR, l&#039;ID du routeur servant \u00e0 d\u00e9partager les \u00e9galit\u00e9s. La priorit\u00e9\u00a00 n&#039;est pas \u00e9ligible. Les \u00e9lections DR\/BDR existantes ne sont pas pr\u00e9emptives. Aucun DR n&#039;est d\u00e9sign\u00e9 sur les liaisons point \u00e0 point.<\/p><\/div><div class=\"os-sec\"><h2>8. Conception de la s\u00e9curit\u00e9 et de la d\u00e9fense<\/h2><p>Limiter la formation de voisins OSPF aux liens rout\u00e9s de confiance\u00a0; utiliser <code data-no-translation=\"\">passive-interface default<\/code> et n&#039;activer que les interfaces de transit. Authentifier chaque adjacence. Lorsque la plateforme le prend en charge, utiliser l&#039;authentification cryptographique par cha\u00eene de cl\u00e9s avec HMAC-SHA-256 (exemple ci-dessous)\u00a0; MD5 (<code data-no-translation=\"\">ip ospf message-digest-key<\/code>Ce protocole est conserv\u00e9 uniquement pour assurer la compatibilit\u00e9 avec les anciens n\u0153uds. Filtrez les protocoles OSPF non autoris\u00e9s (protocole 89) aux limites non fiables\u00a0; \u00e9vitez la redistribution indiscrimin\u00e9e\u00a0; d\u00e9finissez et synth\u00e9tisez les routes, surveillez les fluctuations d\u2019adjacence et les modifications de la base de donn\u00e9es LSDB. L\u2019authentification OSPF ne doit pas \u00eatre consid\u00e9r\u00e9e comme une garantie de confidentialit\u00e9 ou une autorisation de routage.<\/p><pre class=\"code\" data-no-translation=\"\">! Same key chain on both neighbors (e.g. R1 and R2)\nkey chain OSPF-KEYS\n key 1\n  key-string REPLACE-WITH-STRONG-SECRET\n  cryptographic-algorithm hmac-sha-256\n!\ninterface GigabitEthernet0\/0\/0\n ip ospf authentication key-chain OSPF-KEYS<\/pre><p>Remplacez le secret de d\u00e9monstration, ne le stockez pas dans des d\u00e9p\u00f4ts partag\u00e9s, v\u00e9rifiez la compatibilit\u00e9 avec votre version exacte d&#039;iOS XE et g\u00e9n\u00e9rez les cl\u00e9s simultan\u00e9ment des deux c\u00f4t\u00e9s. V\u00e9rifiez avec <code data-no-translation=\"\">show ip ospf interface GigabitEthernet0\/0\/0<\/code>, qui indique l&#039;authentification utilis\u00e9e.<\/p><\/div><div class=\"os-sec\"><h2>9. Flux de travail de d\u00e9pannage<\/h2><p>1) V\u00e9rifier l&#039;\u00e9tat physique et L3 (<code data-no-translation=\"\">show ip interface brief<\/code>). 2) V\u00e9rifier la participation \u00e0 OSPF (<code data-no-translation=\"\">show ip ospf interface brief<\/code>3) V\u00e9rifiez la zone, le type de r\u00e9seau, les temporisateurs, le sous-r\u00e9seau, la MTU, l&#039;authentification et les ID du routeur (<code data-no-translation=\"\">show ip ospf interface<\/code>, <code data-no-translation=\"\">show ip ospf neighbor detail<\/code>). 4) Inspecter la base de donn\u00e9es (<code data-no-translation=\"\">show ip ospf database<\/code>), puis les d\u00e9cisions de routage (<code data-no-translation=\"\">show ip route ospf<\/code>). 5) Inspectez les journaux avant d&#039;utiliser les outils de d\u00e9bogage\u00a0; <code data-no-translation=\"\">debug ip ospf adj<\/code> Peut \u00eatre bruyant, \u00e0 utiliser uniquement dans le cadre d&#039;une maintenance contr\u00f4l\u00e9e.<\/p><\/div><div class=\"os-sec\"><h2>10. Pannes courantes et solutions<\/h2><p>BLOQU\u00c9 \u00c0 L&#039;INITIALISATION\u00a0: Probl\u00e8me de connectivit\u00e9 unidirectionnelle ou de filtrage multicast\/ACL\u00a0; v\u00e9rifiez les messages Hello bidirectionnels. BLOQU\u00c9 \u00c0 L&#039;EXSTART\/L&#039;\u00c9CHANGE\u00a0: examinez les incompatibilit\u00e9s de MTU et l&#039;\u00e9change DBD\u00a0; ne pas utiliser <code data-no-translation=\"\">ip ospf mtu-ignore<\/code> En premi\u00e8re intention\u00a0: VOISIN MANQUANT\u00a0: type de zone\/r\u00e9seau incorrect, interface passive, authentification incorrecte, protocole 89 bloqu\u00e9. ROUTE COMPL\u00c8TE MAIS SANS ROUTE\u00a0: v\u00e9rifier les LSA, le type de zone, le regroupement, la meilleure route \u00e0 distance administrative et la visibilit\u00e9 du pr\u00e9fixe. ROUTE DE RECHANGE INSTABLE\u00a0: les modifications de priorit\u00e9 seules ne remplacent pas la route de renouvellement existante.<\/p><\/div><div class=\"os-sec\"><h2>11. Meilleures pratiques op\u00e9rationnelles<\/h2><p>Utilisez des descriptions d&#039;interface claires, des boucles de routage avec ID de routeur, une bande passante de r\u00e9f\u00e9rence constante, des r\u00e9seaux OSPF point \u00e0 point sur des liaisons rout\u00e9es d\u00e9di\u00e9es, des limites de zone d\u00e9finies, des ABR stables, une surveillance des routes et des adjacences, ainsi qu&#039;un plan de retour en arri\u00e8re \u00e9prouv\u00e9. \u00c9vitez les liaisons virtuelles comme architecture dorsale \u00e0 long terme\u00a0; utilisez-les comme m\u00e9canismes de transition exceptionnels.<\/p><\/div><h2>12. Exemples de configuration compl\u00e8te de Cisco IOS XE<\/h2><p>Remplacez les adresses de laboratoire et les num\u00e9ros d&#039;interface par ceux de votre mat\u00e9riel. Les identifiants des routeurs sont configur\u00e9s manuellement\u00a0; les adresses de bouclage ne sont pas incluses dans ces mod\u00e8les.<\/p><h3>R1 \u2014 Zone ABR 0\/10<\/h3><pre class=\"code\" data-no-translation=\"\">hostname R1\ninterface Loopback0\n ip address 1.1.1.1 255.255.255.255\ninterface GigabitEthernet0\/0\/0\n description Area0-to-R2\n ip address 10.0.12.1 255.255.255.252\n ip ospf 100 area 0\n ip ospf network point-to-point\ninterface GigabitEthernet0\/0\/1\n description Area10-to-R4\n ip address 10.0.14.1 255.255.255.252\n ip ospf 100 area 10\n ip ospf network point-to-point\ninterface GigabitEthernet0\/0\/2\n description Area0-backup-to-R3\n ip address 10.0.13.1 255.255.255.252\n ip ospf 100 area 0\n ip ospf network point-to-point\nrouter ospf 100\n router-id 1.1.1.1\n auto-cost reference-bandwidth 100000\n passive-interface default\n no passive-interface GigabitEthernet0\/0\/0\n no passive-interface GigabitEthernet0\/0\/1\n no passive-interface GigabitEthernet0\/0\/2<\/pre><h3>R2 \u2014 Zone centrale 0<\/h3><pre class=\"code\" data-no-translation=\"\">hostname R2\ninterface Loopback0\n ip address 2.2.2.2 255.255.255.255\ninterface GigabitEthernet0\/0\/0\n description Area0-to-R1\n ip address 10.0.12.2 255.255.255.252\n ip ospf 100 area 0\n ip ospf network point-to-point\ninterface GigabitEthernet0\/0\/1\n description Area0-to-R3\n ip address 10.0.23.1 255.255.255.252\n ip ospf 100 area 0\n ip ospf network point-to-point\ninterface Vlan100\n description Area0-Ethernet-DR-BDR-demo\n ip address 10.0.100.1 255.255.255.0\n ip ospf 100 area 0\n ip ospf priority 200\nrouter ospf 100\n router-id 2.2.2.2\n auto-cost reference-bandwidth 100000\n passive-interface default\n no passive-interface GigabitEthernet0\/0\/0\n no passive-interface GigabitEthernet0\/0\/1\n no passive-interface Vlan100<\/pre><h3>R3 \u2014 Zone ABR 0\/20<\/h3><pre class=\"code\" data-no-translation=\"\">hostname R3\ninterface Loopback0\n ip address 3.3.3.3 255.255.255.255\ninterface GigabitEthernet0\/0\/0\n description Area0-to-R2\n ip address 10.0.23.2 255.255.255.252\n ip ospf 100 area 0\n ip ospf network point-to-point\ninterface GigabitEthernet0\/0\/1\n description Area20-to-R5\n ip address 10.0.35.1 255.255.255.252\n ip ospf 100 area 20\n ip ospf network point-to-point\ninterface GigabitEthernet0\/0\/2\n description Area0-backup-to-R1\n ip address 10.0.13.2 255.255.255.252\n ip ospf 100 area 0\n ip ospf network point-to-point\nrouter ospf 100\n router-id 3.3.3.3\n auto-cost reference-bandwidth 100000\n passive-interface default\n no passive-interface GigabitEthernet0\/0\/0\n no passive-interface GigabitEthernet0\/0\/1\n no passive-interface GigabitEthernet0\/0\/2<\/pre><h3>R4 \u2014 Zone 10<\/h3><pre class=\"code\" data-no-translation=\"\">hostname R4\ninterface Loopback0\n ip address 4.4.4.4 255.255.255.255\ninterface GigabitEthernet0\/0\/0\n description Area10-to-R1\n ip address 10.0.14.2 255.255.255.252\n ip ospf 100 area 10\n ip ospf network point-to-point\ninterface GigabitEthernet0\/0\/1\n description Users-Area10\n ip address 192.168.10.1 255.255.255.0\n ip ospf 100 area 10\nrouter ospf 100\n router-id 4.4.4.4\n auto-cost reference-bandwidth 100000\n passive-interface default\n no passive-interface GigabitEthernet0\/0\/0<\/pre><h3>R5 \u2014 Zone 20<\/h3><pre class=\"code\" data-no-translation=\"\">hostname R5\ninterface Loopback0\n ip address 5.5.5.5 255.255.255.255\ninterface GigabitEthernet0\/0\/0\n description Area20-to-R3\n ip address 10.0.35.2 255.255.255.252\n ip ospf 100 area 20\n ip ospf network point-to-point\ninterface GigabitEthernet0\/0\/1\n description Users-Area20\n ip address 192.168.20.1 255.255.255.0\n ip ospf 100 area 20\nrouter ospf 100\n router-id 5.5.5.5\n auto-cost reference-bandwidth 100000\n passive-interface default\n no passive-interface GigabitEthernet0\/0\/0<\/pre><h2>13. Commandes de v\u00e9rification et de d\u00e9pannage<\/h2><div class=\"grid\"><div class=\"card\"><code data-no-translation=\"\">show ip ospf neighbor<\/code><p>Consultez les \u00e9tats voisins\u00a0; FULL\/- attendu sur les liaisons point \u00e0 point.<\/p><\/div><div class=\"card\"><code data-no-translation=\"\">show ip ospf interface brief<\/code><p>V\u00e9rifiez les interfaces, les zones, les adresses IP et les co\u00fbts activ\u00e9s.<\/p><\/div><div class=\"card\"><code data-no-translation=\"\">show ip ospf interface GigabitEthernet0\/0\/0<\/code><p>V\u00e9rifier les temporisateurs hello\/dead, l&#039;\u00e9tat et le type de r\u00e9seau.<\/p><\/div><div class=\"card\"><code data-no-translation=\"\">show ip ospf database<\/code><p>Inspecter l&#039;inventaire LSA et la s\u00e9quence\/l&#039;\u00e2ge.<\/p><\/div><div class=\"card\"><code data-no-translation=\"\">show ip route ospf<\/code><p>Confirmer les routes O, O IA et E1\/E2 install\u00e9es.<\/p><\/div><div class=\"card\"><code data-no-translation=\"\">show ip ospf border-routers<\/code><p>Voir les ABR\/ASBR connus.<\/p><\/div><div class=\"card\"><code data-no-translation=\"\">show ip protocols<\/code><p>Examiner la participation au processus et les interfaces passives.<\/p><\/div><div class=\"card\"><code data-no-translation=\"\">show logging | include OSPF<\/code><p>Corr\u00e9ler les \u00e9v\u00e9nements de contigu\u00eft\u00e9 et de liaison.<\/p><\/div><div class=\"card\"><code data-no-translation=\"\">ping 10.0.12.2 source 10.0.12.1<\/code><p>Valider la connectivit\u00e9 sur la liaison R1\u2013R2.<\/p><\/div><div class=\"card\"><code data-no-translation=\"\">clear ip ospf process<\/code><p>Perturbateur : r\u00e9initialise les adjacences \u2014 maintenance uniquement.<\/p><\/div><\/div><h2>14. Questions d&#039;entra\u00eenement et r\u00e9ponses d\u00e9taill\u00e9es<\/h2><div class=\"qa\"><b>Sur une liaison R1\u2013R2 d\u00e9di\u00e9e, faut-il \u00e9lire DR\/BDR\u00a0?<\/b><p>Non. Les deux interfaces sont en OSPF point \u00e0 point, donc pas d&#039;\u00e9lection.<\/p><\/div><div class=\"qa\"><b>Pourquoi R4 apprend-il 192.168.20.0\/24 comme O IA\u00a0?<\/b><p>L&#039;itin\u00e9raire prend son origine dans la zone 20 et est distribu\u00e9 par un ABR \u00e0 travers la zone 0 jusqu&#039;\u00e0 la zone 10.<\/p><\/div><div class=\"qa\"><b>Un routeur reste en mode bidirectionnel sur un r\u00e9seau Ethernet de diffusion. Toujours en panne\u00a0?<\/b><p>Non. Entre voisins DROTHER, une adjacence bidirectionnelle peut \u00eatre correcte\u00a0; une adjacence compl\u00e8te se forme avec DR\/BDR.<\/p><\/div><div class=\"qa\"><b>Que signifie le protocole IP 89\u00a0?<\/b><p>Les paquets OSPF utilisent le num\u00e9ro de protocole IP 89, et non le port de destination TCP\/UDP 89.<\/p><\/div><div class=\"qa\"><b>Boucle ExStart apr\u00e8s un changement de circuit. Premiers suspects\u00a0?<\/b><p>Incompatibilit\u00e9 MTU, incompatibilit\u00e9 de type de r\u00e9seau ou n\u00e9gociation\/connectivit\u00e9 DBD.<\/p><\/div><div class=\"qa\"><b>Qu&#039;est-ce qu&#039;un ABR dans ce laboratoire\u00a0?<\/b><p>R1 relie les zones 0 et 10 ; R3 relie les zones 0 et 20.<\/p><\/div><div class=\"qa\"><b>Que fait la configuration par d\u00e9faut de l&#039;interface passive\u00a0?<\/b><p>Emp\u00eache les requ\u00eates Hello\/d&#039;adjacence sur les interfaces jusqu&#039;\u00e0 ce qu&#039;elles soient explicitement activ\u00e9es, tandis que les r\u00e9seaux connect\u00e9s \u00e9ligibles peuvent toujours \u00eatre annonc\u00e9s.<\/p><\/div><div class=\"qa\"><b>Pourquoi d\u00e9finir une bande passante de r\u00e9f\u00e9rence OSPF sur tous les routeurs\u00a0?<\/b><p>Pour une \u00e9volution coh\u00e9rente des co\u00fbts, en particulier pour les liaisons sup\u00e9rieures \u00e0 100 Mbps.<\/p><\/div><div class=\"qa\"><b>Un changement de priorit\u00e9 entra\u00eene-t-il la cr\u00e9ation d&#039;un nouveau DR\u00a0?<\/b><p>Non. L&#039;\u00e9lection DR\/BDR n&#039;est pas pr\u00e9emptive.<\/p><\/div><div class=\"qa\"><b>Une zone de stub peut-elle recevoir des LSA externes de type 5\u00a0?<\/b><p>Non. Les zones de blocage de type 5 utilisent g\u00e9n\u00e9ralement une valeur par d\u00e9faut de l&#039;ABR.<\/p><\/div><h2>15. Sources et v\u00e9rification<\/h2><p>Il s&#039;agit d&#039;un guide CYBER original pour le module MAG212. Le laboratoire \u00e0 cinq routeurs, le sch\u00e9ma et les explications ont \u00e9t\u00e9 r\u00e9dig\u00e9s ind\u00e9pendamment et v\u00e9rifi\u00e9s par rapport aux normes IETF et \u00e0 la documentation Cisco ci-dessous.<\/p><p><a href=\"https:\/\/www.rfc-editor.org\/rfc\/rfc2328.html\" target=\"_blank\" rel=\"noopener\">RFC 2328 \u2014 OSPF Version 2<\/a> \u00b7 <a href=\"https:\/\/www.rfc-editor.org\/rfc\/rfc3101.html\" target=\"_blank\" rel=\"noopener\">RFC 3101 \u2014 OSPF NSSA<\/a> \u00b7 <a href=\"https:\/\/www.rfc-editor.org\/rfc\/rfc5340.html\" target=\"_blank\" rel=\"noopener\">RFC 5340 \u2014 OSPF pour IPv6<\/a> \u00b7 <a href=\"https:\/\/www.cisco.com\/c\/en\/us\/td\/docs\/switches\/lan\/c9000\/lyr3-fwd\/ospf\/ospf-configuration-guide\/ospf.html\" target=\"_blank\" rel=\"noopener\">Guide de configuration Cisco OSPF (IOS XE 17)<\/a> \u00b7 <a href=\"https:\/\/www.cisco.com\/en\/US\/docs\/ios-xml\/ios\/iproute_ospf\/configuration\/xe-3s\/iro-ospfv2-crypto-authen-xe.html\" target=\"_blank\" rel=\"noopener\">Cisco \u2014 Authentification cryptographique OSPFv2<\/a><\/p><div class=\"os-foot\">MAG212 CYBER-ING\u00c9NIERIE DES R\u00c9SEAUX \u00b7 OCTOBRE 2026<br><a href=\"\/fr\/learn\/\">Plus de guides dans Apprendre<\/a> \u00b7 <a href=\"\/fr\/learn\/isis-cheat-sheet\/\">EST-EST<\/a> \u00b7 <a href=\"\/fr\/learn\/eigrp-cheat-sheet\/\">EIGRP<\/a> \u00b7 <a href=\"\/fr\/learn\/bgp-cheat-sheet\/\">BGP<\/a> \u00b7 <a href=\"\/fr\/services\/\">Conseil en r\u00e9seau et s\u00e9minaires<\/a><\/div><\/div>","protected":false},"excerpt":{"rendered":"<p>OSPF field guide: multi-area design, LSA types, neighbor states, five-router IOS XE lab, HMAC-SHA authentication and troubleshooting.<\/p>","protected":false},"author":1,"featured_media":0,"parent":3385,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-3420","page","type-page","status-publish","hentry"],"_hostinger_reach_plugin_has_subscription_block":false,"_hostinger_reach_plugin_is_elementor":false,"_links":{"self":[{"href":"https:\/\/cyber.mag212.com\/fr\/wp-json\/wp\/v2\/pages\/3420","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cyber.mag212.com\/fr\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/cyber.mag212.com\/fr\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/cyber.mag212.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cyber.mag212.com\/fr\/wp-json\/wp\/v2\/comments?post=3420"}],"version-history":[{"count":0,"href":"https:\/\/cyber.mag212.com\/fr\/wp-json\/wp\/v2\/pages\/3420\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/cyber.mag212.com\/fr\/wp-json\/wp\/v2\/pages\/3385"}],"wp:attachment":[{"href":"https:\/\/cyber.mag212.com\/fr\/wp-json\/wp\/v2\/media?parent=3420"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}