Cisco and Server

❗️ Nimalardir o'zgardi ... 👀 Uzbekonacisco.uz — kirganlar biladi. Kirmaganlar — esa yo'q. 🤔 Nima o'zgarganini toping va 3-bepul darsimizga qo'shilish uchun bonusingizni oling 🎁 Kim birinchilardan topgan bo'lsa, komentariya yozish esingizdan chiqmasin-a ! 👇 @uzbekonacisco

🌐 DNS Checker — domeningiz dunyo bo'ylab "tarqaldimi" yo'qmi, bir clickda bilishingiz mumkin! Saytingizning DNS yozuvlarini o'zgartirdingizmi? Yangi domen yoki subdomen ochdingizmi? Hosting almashtirdingizmi? Unda sizga dnschecker.org kerak bo'ladi! 🔥 ⚙️ Bu nima qiladi? DNS o'zgarishlari butun dunyo bo'ylab darhol tarqalmaydi — bu jarayon 48 soatgacha vaqt olishi mumkin. DNS Checker esa dunyoning 100+ davlatidagi serverlardan sizning domeningizni tekshirib, qayerda yangilangan-u qayerda hali eski ma'lumot turganini xaritada ko'rsatib beradi! 🗺 ✅ — DNS yangilangan ❌ — hali yangilanmagan 📋 Tekshirsa bo'ladigan yozuvlar: 🔹 A / AAAA — IP manzil (IPv4 / IPv6) 🔹 CNAME — subdomenni asosiy domenga bog'lash 🔹 MX — pochta serverlari 🔹 NS — nameserverlar 🔹 TXT — SPF, DKIM, DMARC sozlamalari 🔹 va boshqa ko'plab yozuvlar (SOA, CAA, PTR, SRV...) 💡 Bonus: Saytda DNS tekshirishdan tashqari yana ko'plab bepul foydali asboblar bor — "What is my IP", SSL sertifikat tekshiruvi, port scanner, WHOIS lookup, QR scanner va h.k. 🆓 To'liq bepul, ro'yxatdan o'tish shart emas! 🔗 dnschecker.org #DNS #Hosting #Domen #WebDev #ITbilim

🎓 CISCO SERTIFIKATINGIZ MUDDATI TUGAYAPTIMI? ✅ Imtihon topshirmasdan CCNA va CCNP sertifikatlarini qanday uzaytirish mumkinligini bilib oling! 📹 Yangi video yuklandi! Bu videoda: 🔹 CE Credits nima ekanligi 🔹 CCNA uchun 30 kredit qanday yig'iladi 🔹 CCNP uchun 80 kredit qanday yig'iladi 🔹 Bepul Cisco kurslaridan kredit yig'ish yo'llari 🔹 Recertify qilishning to'liq jarayoni 💡 Cisco sertifikatini yangilash uchun har doim imtihon topshirish shart emas — CE Credits orqali ham mumkin! ▶️ Videoni tomosha qiling: https://youtu.be/vsO5LPpbNKQ?si=fKDvlT4E0SP5-VNk 👍 Foydali bo'lsa do'stlaringiz bilan ulashing! @uzbekonacisco #Cisco #CCNA #CCNP #CECredits #Recertification #ITUzbek #NetworkingUzbek

Yoz oyi uchun hech qanday kursga borishni reja qilmay turing, rad etib bo'lmaydigan taklif tayyorlayapmiz sizlar uchun. Bugun CCNA/CCNP sertifikati borlar uchun, qanday qilib exam topshirmasdan turib, sertifikatni amal qilish muddatini yana 3yildan 9 yilgacha cho'zish mumkinligini ko'rsatib bersam nima deysizlar? @uzbekonacisco

#new_ccna Shogirtimizdan Hayitga Sovg'a. Alloh hayirli qilsin. @uzbekonacisco.uz

🔴 OSPFv3 — CCNA da aytilmaydigan narsalar (Chapter 10 — ENCOR 350-401) Ko'pchilik OSPFv3 ni "OSPFv2 ning IPv6 versiyasi" deb biladi. Lekin bu to'liq to'g'ri emas. Keling, chuqurroq qaraymiz 👇 ━━━━━━━━━━━━━━━ 1️⃣ IP manzil va topologiya ajratildi OSPFv2 da Router LSA ichida topologiya ham, IP prefix ham birga yurardi. Yangi IP qo'shsang → butun SPF qayta hisoblandi. OSPFv3 da bular ajratildi: → Router LSA = faqat topologiya → Intra-area Prefix LSA = faqat IP manzillar Natija: IP o'zgarganda SPF qayta ishlamaydi ✅ ━━━━━━━━━━━━━━━ 2️⃣ Authentication OSPF dan chiqarildi OSPFv2 da authentication to'g'ridan-to'g'ri OSPF packet ichida edi. OSPFv3 da bu vazifa IPsec Extension Header ga o'tkazildi. OSPF packet header 24 byte dan 16 byte ga tushdi. ━━━━━━━━━━━━━━━ 3️⃣ Umumiy subnet shart emas OSPFv2: qo'shni bo'lish uchun bir xil subnet bo'lishi shart ✋ OSPFv3: ikki router subnet'lari farqli bo'lsa ham, link-local manzil bir xil linkda bo'lsa — adjacency o'rnatiladi ✅ ━━━━━━━━━━━━━━━ 4️⃣ LSA flooding yangicha ishlaydi Har bir LSA da endi LS Type maydoni bor (16-bit). Uning ichidagi bitlar: U-bit → noma'lum LSA ni drop qilma, forward qil S1/S2 → flooding qayerga borishi kerakligini belgilaydi:

00 → faqat shu link
01 → faqat shu area  
10 → butun OSPF domain

OSPFv2 da bu "hardcoded" edi 🤯 ━━━━━━━━━━━━━━━ 5️⃣ Instance ID — kam bilinadi Bir xil segmentda turli OSPFv3 guruhlarni ajratish mumkin.

R1 (Instance 0) ↔️ R2 (Instance 0) ✅
R1 (Instance 0) ↔️ R3 (Instance 1) ❌

Instance ID mos kelmasa → packet ignore qilinadi. Xuddi "parol" kabi 🔑 ━━━━━━━━━━━━━━━ 6️⃣ OSPFv3 = IPv4 + IPv6 bir jarayonda RFC 5838 ga ko'ra OSPFv3 bitta jarayon ichida IPv4 va IPv6 ni bir vaqtda ishlata oladi.

ospfv3 1 ipv6 area 0  → IPv6 uchun
ospfv3 1 ipv4 area 0  → IPv4 uchun

CCNA da bu umuman aytilmaydi 😏 ━━━━━━━━━━━━━━━ 7️⃣ IPv6 summarization da yashirin xato 2001:DB8::/65 ni hisoblayotganda ko'pchilik 0x20 = 20 deb o'ylaydi. To'g'risi: 0x20 = 32 (decimal) ‼️ Har doim hex kalkulyator ishlatish — bir xatoni oldini oladi. ━━━━━━━━━━━━━━━ @cisco_server

📡 OSPF — CCNA da aytilmagan sirlar (Chapter 9 — ENCOR 350-401) ━━━━━━━━━━━━━━ CCNA da OSPF ni "o'rgandim" deb o'ylaysizmi? 😏 Mana CCIE darajasidagi haqiqat 👇 ━━━━━━━━━━━━━ 🔴 1. LSA lar — 6 xil, siz 2 tasini bilasiz CCNA: "Type 1 va Type 2 bor" Aslida: Type 1 → Router o'zi (area ichida) Type 2 → DR (multi-access segment) Type 3 → ABR (arealar orasida) ⭐️ Type 4 → ABR (ASBR qayerda?) Type 5 → ASBR (external routes) Type 7 → NSSA ichida external routes 💡 Eng muhimi: Type 3 ni ABR yaratadi, router emas! ━━━━━━━━━━━━━━ 🔴 2. ABR — oddiy router emas ABR uchun 3 ta TEMIR QOIDA: ▪️ Type 1 LSA kelsa → backbone VA non-backbone areaga Type 3 yarat ▪️ Area 0 dan Type 3 kelsa → faqat non-backbone area uchun yarat ▪️ Non-backbone dan Type 3 kelsa → boshqa areaga HECH QACHON yuborma! ⚠️ Bu qoidani bilmasang → Discontiguous network tuzog'iga tushasiz! ━━━━━━━━━━━━━━ 🔴 3. LSA Age — router "o'lganini" qanday bilasiz? Age = 0 → LSA tug'ildi Age = 1800s → Router "Tirikman!" deb yangi LSA yuboradi ♻️ Age = 3600s → LSA o'ladi, LSDB dan o'chadi ❌ 💡 Lekin amalda router o'chsa 40 soniyada Dead Interval ishga tushadi 3600s ni kutmaysiz! ━━━━━━━━━━━━━━ 🔴 4. Intra-area DOIM g'alaba qiladi R1 dan R4 ga 2 ta yo'l: ▪️ Ethernet: metric 5 (inter-area) ▪️ Serial: metric 111 (intra-area) OSPF serial ni tanlaydi! 😲 Sababi: Intra-area > Inter-area >External Metrika emas — YO'L TURI muhim! ━━━━━━━━━━━━━━ 🔴 5. Summarization — LSDB ni o'zgartiradigan qurol Summarizationsiz: Area 1 → 15 ta Type 3 LSA → Area 0 😓 Summarization bilan: Area 1 → 1 ta Type 3 LSA → Area 0 ✅ Buyrug'i: area 12 range 172.16.0.0 255.255.0.0 Bonus: not-advertise qo'shsang → route filter ham bo'ladi! 🎯 ━━━━━━━━━━━━━━ 🔴 6. Discontiguous Network — ko'pchilik tushmaydigan tuzoq Area 0 uzluksiz bo'lmasa nima bo'ladi? Area 12 — Area 23 — Area 34 Traffic Area 23 dan o'tmoqchi → OSPF bu ABR qoidalari tufayli routelarni inject QILMAYDI ❌ Yechim: Area 0 ni doim CONTIGUOUS saqlang! ✅ ━━━━━━━━━━━━━━ 💎 XULOSA — CCNA vs CCNP/CCIE CCNA: "OSPF area bor, DR bor" CCNP: "LSA turlari, ABR qoidalari" CCIE: "Nima uchun shunday ishlaydi?" Eng kuchli network engineer — protokolni ichidan tushunadigani! 🧠 ━━━━━━━━━━━━━━ 👇 Savol bo'lsa — kommentga yozing! @cisco_server

🧠 CCNA da aytishmagan OSPF sirlari! (Chapter 8 — ENCOR 350-401) 2-qism. #6 — OSPF Process izolyatsiyasi 🔒

router ospf 1 → O'z LSDB si
router ospf 2 → O'z LSDB si

Ikkalasi bir-birini ko'rmaydi!

redistribute ospf 1 ← shu bo'lmasa
                       marshrut o'tmaydi

Real hayotda: Ikki kompaniya birlashdi, har birida alohida OSPF process bor — redistribute qilmasang ular ko'r! 👁

━━━━━━━━━━━━━━━━━━ #7 — Passive Interface: Noto'g'ri tushuncha ❗️ Ko'pchilik o'ylaydi:

"Passive interface = OSPF o'chirildi" ❌

Aslida:

Passive Interface:
✅ Tarmoq LSDB ga qo'shiladi
✅ OSPF e'lon qilinadi
❌ Hello yuborilmaydi
❌ Neighbor bo'lmaydi

Tarmoqni e'lon qil, lekin neighbor qabul qilma! 🎯

━━━━━━━━━━━━━━━━━━ #8 — Network Statement haqiqiy vazifasi 🎭

network 10.0.0.0 0.0.0.255 area 0

Ko'pchilik o'ylaydi:

"10.0.0.0 tarmoqni e'lon qiladi" ❌

Aslida:

"10.0.0.x IP li interfeysdagi OSPF ni YOQADI" ✅

Interfeysning o'zi LSA orqali e'lon qilinadi — network statement emas! ━━━━━━━━━━━━━━━━━━ #9 — DR saylovida RID tuzog'i ⚠️

Barcha priority = 1 (default)
    ↓
RID taqqoslanadi
    ↓
Eng katta RID = DR

❌ Yomon amaliyot:

RID ni o'zgartirish orqali DR ni boshqarish

✅ Professional amaliyot:

ip ospf priority 100 ← DR bo'lsin
ip ospf priority 0   ← hech qachon DR bo'lmasin

━━━━━━━━━━━━━━━━━━ #10 — ExStart: Yashirin muammo 🔍

Ikki router ExStart holatida qolib ketdi?

Sabab ko'pincha:

MTU mismatch! ← 90% holat
DBD paket o'tmayapti

Tekshirish:

show ip ospf neighbor ← ExStart ko'rinsa
show interface        ← MTU tekshir

━━━━━━━━━━━━━━━━━━ 💬 Qaysi biri sizni hayratda qoldirdi? Izohda yozing! 👇 @cisco_server

🧠 CCNA da aytishmagan OSPF sirlari! (Chapter 8 — ENCOR 350-401) 2-qism. #6 — OSPF Process izolyatsiyasi 🔒

router ospf 1 → O'z LSDB si
router ospf 2 → O'z LSDB si

Ikkalasi bir-birini ko'rmaydi!

redistribute ospf 1 ← shu bo'lmasa
                       marshrut o'tmaydi

Real hayotda: Ikki kompaniya birlashdi, har birida alohida OSPF process bor — redistribute qilmasang ular ko'r! 👁

━━━━━━━━━━━━━━━━━━ #7 — Passive Interface: Noto'g'ri tushuncha ❗️ Ko'pchilik o'ylaydi:

"Passive interface = OSPF o'chirildi" ❌

Aslida:

Passive Interface:
✅ Tarmoq LSDB ga qo'shiladi
✅ OSPF e'lon qilinadi
❌ Hello yuborilmaydi
❌ Neighbor bo'lmaydi

Tarmoqni e'lon qil, lekin neighbor qabul qilma! 🎯

━━━━━━━━━━━━━━━━━━ #8 — Network Statement haqiqiy vazifasi 🎭

network 10.0.0.0 0.0.0.255 area 0

Ko'pchilik o'ylaydi:

"10.0.0.0 tarmoqni e'lon qiladi" ❌

Aslida:

"10.0.0.x IP li interfeysdagi OSPF ni YOQADI" ✅

Interfeysning o'zi LSA orqali e'lon qilinadi — network statement emas! ━━━━━━━━━━━━━━━━━━ #9 — DR saylovida RID tuzog'i ⚠️

Barcha priority = 1 (default)
    ↓
RID taqqoslanadi
    ↓
Eng katta RID = DR

❌ Yomon amaliyot:

RID ni o'zgartirish orqali DR ni boshqarish

✅ Professional amaliyot:

ip ospf priority 100 ← DR bo'lsin
ip ospf priority 0   ← hech qachon DR bo'lmasin

━━━━━━━━━━━━━━━━━━ #10 — ExStart: Yashirin muammo 🔍

Ikki router ExStart holatida qolib ketdi?

Sabab ko'pincha:

MTU mismatch! ← 90% holat
DBD paket o'tmayapti

Tekshirish:

show ip ospf neighbor ← ExStart ko'rinsa
show interface        ← MTU tekshir

━━━━━━━━━━━━━━━━━━ 💬 Qaysi biri sizni hayratda qoldirdi? Izohda yozing! 👇 @cisco_server

🧠 CCNA da aytishmagan OSPF sirlari! (Chapter 8 — ENCOR 350-401) ━━━━━━━━━━━━━━━━━━ #1 — DR preemption yo'q! 🚫 Ko'pchilik bilmaydi: DR saylovdan keyin yangi, yaxshiroq router kelsa ham DR o'zgarmaydi!

R4 = DR (priority: 1)
R1 keldi (priority: 100) 👑

Natija: R4 HALI HAM DR! 😮

DR o'zgarishi uchun:

clear ip ospf process ← majburiy!

OSPF DR preemptive emas — bu dizayn qarori!

━━━━━━━━━━━━━━━━━━ #2 — Wait Timer: Ko'pchilik bilmagan taymер ⏳ Router yonganda darhol DR saylovga qatnashmaydi!

Router yondi
    ↓
Wait Timer = 40 soniya ⏳
    ↓
Boshqalar yonishini kutadi
    ↓
Keyin saylov! ✅

Nega?

Agar kutmasа → Birinchi yongan router doim DR bo'lib qolardi! ❌

━━━━━━━━━━━━━━━━━━ #3 — OSPF Cost muammosi 📊 Default reference bandwidth = 100 Mbps

FastEthernet (100M) → Cost: 1
GigabitEthernet (1G) → Cost: 1
10 GigabitEthernet  → Cost: 1

❌ Hammasi bir xil! OSPF tezroq yo'lni topa olmaydi! Yechim:

auto-cost reference-bandwidth 40000

FastEthernet  → Cost: 400
GigabitEth   → Cost: 40
10GigE       → Cost: 4

✅ Endi farq bor!

⚠️ Barcha routerlarda bir xil qiymat bo'lishi SHART!

━━━━━━━━━━━━━━━━━━ #4 — Loopback /32 muammosi 🔄

interface Loopback0
 ip address 192.168.1.1 255.255.255.0

OSPF e'lon qiladi: 192.168.1.1/32 😮 /24 emas! Yechim:

interface Loopback0
 ip ospf network point-to-point

Endi OSPF e'lon qiladi: 192.168.1.0/24 ✅ ━━━━━━━━━━━━━━━━━━ #5 — MTU mismatch: Yashirin dushman 👻

R1 MTU: 1500 byte
R2 MTU: 1400 byte

Natija:

Neighbor: ✅ ko'rinadi
Adjacency: ❌ FULL bo'lmaydi!
Exchange holatida qolib ketadi 😱

Tezkor yechim:

ip ospf mtu-ignore ← tekshirishni o'chir

Professional yechim:

MTU larni bir xil qil! ← asil yechim

━━━━━━━━━━━━━━━━━━ Davomi bor... @cisco_server

🔥 Ko'pchilik bilmagan OSPF sirlari — #1 ━━━━━━━━━━━━━━━━━━ ❓ Savol: Quyidagi komanda nima qiladi?

router ospf 1
  network 10.0.0.0 0.0.0.255 area 0

Ko'pchilikning fikri::

"10.0.0.0 tarmoqni OSPF ga e'lon qiladi" — NOTO'G'RI ❌

━━━━━━━━━━━━━━━━━━ ✅ To'g'ri javob: network komandasi tarmoqni emas — interfeysdagi OSPF ni YOQADI! Keyin o'sha interfeys LSA orqali o'zi e'lon qilinadi 📡 ━━━━━━━━━━━━━━━━━━ 🧠 Misol bilan tushunamiz: Router 3 ta interfeysi bor:

Gi0/0 → 10.0.0.1  ✅ mos keladi
Gi0/1 → 10.0.10.1 ❌ mos kelmaydi
Gi0/2 → 192.168.1.1 ❌ mos kelmaydi

network 10.0.0.0 0.0.0.255 area 0 👆 Bu komanda faqat Gi0/0 da OSPF ni yoqadi ━━━━━━━━━━━━━━━━━━ 🎯 Wildcard mask nima qiladi? Wildcard Ma'nosi 0.0.0.0 Faqat aynan shu IP 0.0.0.255 /24 dagi barcha IP lar 255.255.255.255 Barcha interfeyslari ━━━━━━━━━━━━━━━━━━ 💡 1 gap bilan yodla:

Network statement — tarmoq e'lon qilmaydi, interfeysdagi OSPF ni YOQADI!

━━━━━━━━━━━━━━━━━━ 📌 Bu bilim CCNP/CCIE imtihonlarida tez-tez chiqadi! 👇 Buni bilardingmidingiz? Komentariyada kutib qolamiz! @cisco_server #OSPF #Cisco #CCNA #CCNP #CCIE #Networking #Tarmoq

#Encore 📡 ENCOR 350-401 | Chapter 7 📡 EIGRP — CCNA da aytilmagan KEY POINTS ━━━━━━━━━━━━━━━━━━ 🧠 DUAL Algoritmi EIGRP oddiy distance vector emas. DUAL (Diffusing Update Algorithm) loop-free backup yo'llarni oldindan hisoblaydi va convergence ni tezlashtiradi. ━━━━━━━━━━━━━━━━━━ 📊 FD, RD va Feasibility Condition - FD (Feasible Distance) — router o'zi hisoblagan to'liq path metric - RD (Reported Distance) — qo'shni e'lon qilgan o'z masofasi - Feasibility Condition: ✅ RD < FD → Feasible Successor ❌ RD ≥ FD → Backup sifatida qabul qilinmaydi (loop xavfi) 💡 RD — bu qo'shni masofasi, to'liq path metric emas! Path metric = RD + o'zingning link cost. ━━━━━━━━━━━━━━━━━━ ⚖️ Unequal-Cost Load Balancing EIGRP variance multiplier orqali har xil metrikdagi yo'llarni bir vaqtda ishlatadi. Variance = Feasible Successor FD ÷ Successor FD (yuqoriga yaxlitlanadi) Feasible Successor FD < Variance qiymati bo'lsa → RIB ga o'rnatiladi. ━━━━━━━━━━━━━━━━━━ 🔄 Convergence: Passive vs Active - Passive (P) → topology barqaror ✅ - Active (A) → yo'l yo'qoldi, DUAL hisoblash boshlandi ⚙️ Feasible Successor bor → darhol Passive ga qaytadi (hech kim bilmaydi) Feasible Successor yo'q → Query jarayoni boshlanadi. ━━━━━━━━━━━━━━━━━━ 📨 Query / Reply Mexanizmi Query kelganda router MAJBURIY javob berishi shart. 2 ta to'g'ri javob: 1️⃣ "Bu prefix menda yo'q" 2️⃣ "Menda boshqa yo'l bor" (+ attributes) Jim qolish = o'lim 💀 Reply Status Flag — router yuborgan har bir query uchun, har bir qo'shni bo'yicha alohida kuzatiladi. Barcha flag = 0 bo'lganda DUAL yakunlanadi. ━━━━━━━━━━━━━━━━━━ 🆘 SIA — Stuck In Active Query ga 3 daqiqada reply kelmasa → adjacency RESET (faqat o'sha prefix emas, BARCHA prefix lar uchun!) 1.5 daqiqada SIA-Query yuboriladi: "Sen tiriksan, lekin nima bo'ldi?" Hello timer ≠ SIA-Query: - Hello → "Qo'shni tirikmi?" (adjacency) - SIA-Query → "DUAL hisoblash tugatdingmi?" (computation) Router tirik bo'la turib ham javob bera olmasligi mumkin — chunki u ham chuqurroq birovni kutmoqda! ━━━━━━━━━━━━━━━━━━ 📦 Classic vs Wide Metrics Classic → delay 10μs, bandwidth kbps ❌ 11 Gbps va 50 Gbps ni ajrata olmaydi Wide → delay pikosekund (10⁻¹²), 65,536 ga ko'paytirilgan ✅ 655 Tbps gacha masshtab K₆ → jitter, energy kabi extended attribute lar uchun qo'shimcha qiymat ━━━━━━━━━━━━━━━━━━ 🗺 Route Summarization — Null0 siri R2 summary advertise qilganda o'z routing table iga avtomatik: 172.16.0.0/16 → Null0 ⛔️ qo'shadi. Mavjud bo'lmagan /24 ga paket kelsa: → Longest Match → Null0 → DROP → Loop emas, Black Hole nazorat ostida ⚠️ Summarization ishlashi uchun har bir region ga UNIQUE address blok berilishi shart. Bir xil summary → Black Hole! ━━━━━━━━━━━━━━━━━━ ⏱️ Timers Fast Slow (T1↓) Hello │ 5 sec │ 60 sec Hold │ 15 sec │ 180 sec Hold = Hello × 3 (default) Hold = 0 → neighbor unreachable → DUAL ga topology change xabari ━━━━━━━━━━━━━━━━━━ #EIGRP #CCNP #ENCOR #Networking @cisco_server

☑️ Longest prefix → har doim birinchi ☑️ EIGRP internal AD = 90 (OSPF dan ustun) ☑️ iBGP AD = 200 (eng past ishonch) ☑️ Ethernet + static = Fully Specified ☑️ Holddown = yaxshi info ni bloklaydi ☑️ OSPF Full state = LSDB sinxron ☑️ ECMP = barcha IGP ☑️ Unequal-Cost = faqat EIGRP ☑️ vrf forwarding → keyin ip address ☑️ Null0 = summary + loop prevention ☑️ RIB = Control Plane ☑️ FIB = Data Plane ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 📚 ENCOR 350-401 Official Cert Guide 2nd Edition — Chapter 6 ✍️ CCIE Enterprise Infrastructure seriyasidan @cisco_server

#Encore 📡 ENCOR 350-401 | Chapter 6 IP Routing Essentials 🔥 CCNA da aytilmagan KEY POINTS ━━━━━━━━━━━━━━━━━━ 1️⃣ TERMINOLOGIYA FARQI Path — ikki tarmoq orasidagi mavjud havolalar Route — routing protokoli tanlagan yo'l (RIB da) ⚡️ CCNA da path = route deyiladi ENCOR da bular FARQ QILADI ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 2️⃣ RIP TIMERLAR 🕐 Update → 30s (table yuborish) 🕐 Invalid → 180s (update kelmasa → invalid) 🕐 Holddown → 180s (yomon info bloklash) 🕐 Flush → 240s (table dan o'chirish) ⚡️ Holddown nima qiladi? Route tushgandan keyin 180s davomida "yaxshi" yangi ma'lumotni QABUL QILMAYDI → Routing loop oldini oladi ⚡️ RIP da Hello YO'Q Qo'shni o'ligini 180s kutib bilib oladi (OSPF = 40s, EIGRP = 15s) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 3️⃣ OSPF FLOODING QACHON TUGAYDI? Down → Init → 2-Way → Exchange → FULL ⚡️ Router "tugadi" deb bilmaydi U LSDB ni qo'shnisi bilan TAQQOSLAYDI Full state = LSDB bir xil = sinxron ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 4️⃣ PATH SELECTION — 3 QADAM 1. Prefix Length /28 > /26 > /24 2. AD past AD → ustun 3. Metric past metric → ustun 📋 DEFAULT AD JADVALI Connected → 0 Static → 1 eBGP → 20 EIGRP internal → 90 ✅ OSPF → 110 ✅ IS-IS → 115 RIPv2 → 120 EIGRP external → 170 iBGP → 200 ✅ ⚡️ iBGP AD = 200 CCNA da o'tilmaydi BGP iBGP path tanlasa → RIB ga AD=200 OSPF (110) uni preempt QILMAYDI ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 5️⃣ ECMP vs UNEQUAL LOAD BALANCING ECMP → barcha IGP (RIP, EIGRP, OSPF, IS-IS) • Metric bir xil → ikkala path RIB ga • Traffic teng taqsimlanadi Unequal-Cost → FAQAT EIGRP • Default o'chiq — variance bilan yoqiladi • Metric farqli → nisbatga qarab taqsimlaydi ⚡️ show ip route — ECMP ko'rinadi ⚡️ show ip route x.x.x.x — traffic share count ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 6️⃣ STATIC ROUTE — 3 TUR Directly Attached ip route net mask INTERFACE → Faqat P2P (Serial) da ishlating! Recursive ip route net mask NEXT-HOP-IP → Ethernet da xavfli — link tushsa noto'g'ri interfeysga o'tib ketadi Fully Specified ✅ ip route net mask INTERFACE NEXT-HOP-IP → Ethernet + static = HAR DOIM shu! ⚡️ Ethernet + Directly Attached = XATO Har paket uchun ARP ishlaydi → CPU va xotira sarflanadi → tizim beqaror ⚡️ Ethernet + Recursive = XAVFLI Link tushsa → RIP 180s kutadi Static darhol noto'g'ri yo'lga o'tadi ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 7️⃣ FLOATING STATIC — BACKUP TEXNIKA ip route 10.0.0.0 255.0.0.0 10.1.1.2 10 ip route 10.0.0.0 255.0.0.0 Serial1/0 210 AD=10 → asosiy (RIB da ko'rinadi) AD=210 → backup (asosiy tushsa faollashadi) ⚡️ AD o'zgartirish routing loop ga olib kelishi mumkin — ehtiyot bo'ling! ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 8️⃣ NULL0 — LOOP OLDINI OLISH ip route 172.16.0.0 255.255.240.0 Null0 Aniq route (longer match) → yo'naltiriladi ✅ Aniq route yo'q → Null0 DROP ✅ (loop yo'q) ⚡️ Summary route + Null0 = standart pattern ISP lar va enterprise da keng ishlatiladi ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 9️⃣ VRF — KOMANDALAR TARTIBI vrf definition MGMT address-family ipv4 interface GigabitEthernet0/3 vrf forwarding MGMT ip address 10.0.3.1 255.255.255.0 ⚡️ vrf forwarding kiritilganda IP manzil AVTOMATIK o'chadi — normal holat! Keyin qayta yozing ⚡️ show ip route — VRF interfeyslar KO'RINMAYDI show ip route vrf MGMT — ko'rinadi ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔟 RIB vs FIB — ENG MUHIM FARQ RIB (Routing Table) • Control Plane • RAM da saqlanadi • Best path hisoblash • show ip route FIB / CEF (Forwarding Table) • Data Plane • TCAM — hardware darajasida • Real paket yo'naltirish • show ip cef ⚡️ SDN va Controller-based arxitekturada Control Plane va Data Plane ajratish ENCOR ning asosiy mavzularidan biri ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✅ IMTIHON UCHUN CHEAT SHEET