📝 Section Review: Services & Security
اہم نکاتKey TakeawaysKey Takeaways
- DHCP: static IPs ہمیشہ exclude کریں؛ multi-VLAN designs کے لیے relay؛ options (جیسے 66) اس کی طاقت بڑھاتے ہیں۔DHCP: static IPs hamesha exclude karein; multi-VLAN designs ke liye relay; options (jaise 66) is ki taqat barhate hain.DHCP: always exclude static IPs; use relay for multi-VLAN designs; options (like 66) extend its power.
- NTP authentication لازمی ہے — logs، certs اور troubleshooting کے لیے درست وقت چاہیے۔NTP authentication lazmi hai — logs, certs aur troubleshooting ke liye durust waqt chahiye.NTP authentication is non-negotiable — logs, certs, and troubleshooting need correct time.
- FHRP choice: HSRP (Cisco)، VRRP (open)، GLBP (load-balancing)۔ Preempt + tracking failover کو deterministic بناتے ہیں۔FHRP choice: HSRP (Cisco), VRRP (open), GLBP (load-balancing). Preempt + tracking failover ko deterministic banate hain.FHRP choice: HSRP (Cisco), VRRP (open), GLBP (load-balancing). Preempt + tracking make failover deterministic.
- CoPP + uRPF + advanced ACLs expert-level security کی بنیاد ہیں۔CoPP + uRPF + advanced ACLs expert-level security ki bunyaad hain.CoPP + uRPF + advanced ACLs form the expert-level security baseline.
خود جانچ (مشق)Self-Check (Practice)Self-Check (Practice)
یہ مشقی سوالات ہیں، امتحانی سوالات نہیں۔These are practice questions, not exam questions.These are practice questions, not exam questions.
❓ DHCP relay (helper-address) کیا کرتا ہے؟DHCP relay (helper-address) kya karta hai?What does DHCP relay (helper-address) do?
یہ client broadcast کو دوسرے subnet کے مرکزی DHCP server تک پہنچاتا ہے — ایک سرور کئی VLANs کو serve کرتا ہے۔Ye client broadcast ko doosre subnet ke markazi DHCP server tak pohonchata hai — ek server kai VLANs ko serve karta hai.It forwards client broadcasts to a central DHCP server in another subnet — one server serves many VLANs.
❓ HSRP، VRRP، GLBP کا موازنہ کریں۔HSRP, VRRP, GLBP ka muqabla karein.Compare HSRP, VRRP, GLBP.
HSRP: Cisco active/standby۔ VRRP: open-standard master/backup۔ GLBP: Cisco، gateways پر active load-balancing۔HSRP: Cisco active/standby. VRRP: open-standard master/backup. GLBP: Cisco, gateways par active load-balancing.HSRP: Cisco active/standby. VRRP: open-standard master/backup. GLBP: Cisco, active load-balancing across gateways.
❓ CoPP کس سے حفاظت کرتا ہے؟CoPP kis se hifazat karta hai?What does CoPP protect against?
یہ control plane کی طرف جانے والے ٹریفک کو rate-limit کرتا ہے تاکہ حملہ CPU ختم کر کے routing نہ مار سکے۔Ye control plane ki taraf jane wale traffic ko rate-limit karta hai taake attack CPU khatam kar ke routing na maar sake.It rate-limits traffic destined for the control plane so attacks can't exhaust the CPU and kill routing.
❓ uRPF spoofing کیسے روکتا ہے؟uRPF spoofing kaise rokta hai?How does uRPF stop spoofing?
یہ source IP کی تصدیق routing table سے کرتا ہے۔ Strict = وہی receiving interface؛ loose = کوئی بھی انٹرفیس جہاں route ہو۔Ye source IP ki tasdeeq routing table se karta hai. Strict = wahi receiving interface; loose = koi bhi interface jahan route ho.It verifies the source IP via the routing table. Strict = must come via the receiving interface; loose = any interface with a route.