1 / 36

Understanding and troubleshooting of Nat address Translation( NAT) and IP Routing Protocols

Understanding and troubleshooting of Nat address Translation( NAT) and IP Routing Protocols. Cisco Support Community. Technology. Process. Manas R Moothedath Sumit Kothiyal. NAT – A Practical approach Basic working of NAT Different types of NAT Typical NAT deployment scenarios

stacia
Download Presentation

Understanding and troubleshooting of Nat address Translation( NAT) and IP Routing Protocols

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Understanding and troubleshooting of Nat address Translation( NAT) and IP Routing Protocols Cisco Support Community Technology Process Manas R Moothedath SumitKothiyal

  2. NAT – A Practical approach • Basic working of NAT • Different types of NAT • Typical NAT deployment scenarios • Best practices for NAT deployment • Troubleshooting IP Routing Protocols – I • Why - Routing Protocols? • Types of Routing Protocols • Basic configuration and working of EIGRP • Basic configuration and working of OSPF Cisco Support Community Technology Process Agenda

  3. NAT - A PRACTICAL APPROACH

  4. Why do we need NAT? Different types of NAT Case Studies Best Practices for NAT deployment AGENDA

  5. Security Hide user identity IPv4 Address exhaustion Reference 1:Many WHY NAT?

  6. Different Flavors of NAT: • Static NAT • 1:1 Static NAT • Port address translation (Port Forwarding) • Dynamic NAT • 1:1 Dynamic NAT • Dynamic NAT with overload

  7. Common Scenarios

  8. Scenario 1: 10 Public IPs 10 users to access internet

  9. Scenario 1: 10 Public IPs 10 users to access internet

  10. Scenario 2: 10 Public IPs 10 users grown to 500 users!

  11. Scenario 2: 10 Public IPs 10 users grown to 500 users!

  12. Scenario 3: Single Public IP Single Server

  13. Scenario 3: Single Public IP Single Servers

  14. Scenario 4: Single Public IP Multiple Servers

  15. Scenario 4: Single Public IP Multiple Servers

  16. Different types of NAT addresses: SRC: IL SRC: OL DST: OL DST: OG IL = Inside Local = 192.168.1.1OL = Outside Local = 100.100.100.100 IG = Inside Global = 1.1.1.1 OG = Outside Global = 100.100.100.100

  17. Special Scenarios

  18. Scenario 1: Multiple ISPs in place Dual-Homed Setup High number of inside users

  19. Scenario 1: Multiple ISPs in place Dual-Homed Setup High number of inside users

  20. Scenario 2: Partner Server access Partner in Outside domain Protected Server

  21. Scenario 2: Partner Server access Partner in Outside domain Protected Server

  22. Commonly Fallacies

  23. Scenario 1: Missing the ‘match interface’ in dual-homed Dual-Homed Setup Route lookup ? ? ? ? High number of inside users

  24. Scenario 2: Trying to access 1 Server with 2+ ISPs Dual-Homed Setup High number of inside users

  25. Scenario 2: Trying to access 1 Server with 2+ ISPs

  26. Some more Pitfalls: • wrong network mask in pool. • permit ip any any in a NAT ACL • log in the ACL. • NAT Exemption for VPN traffic.

  27. IP Routing Protocols – Part 1

  28. Agenda • EIGRP – Salient Features • EIGRP Dual Algorithm • The EIGRP Hello • OSPF – Salient Features • OSPF – Working • OSPF – Things to remember

  29. EIGRP – Salient Features • Shares an update only when there is a change. • Has ‘triggered’ updates to neighbors • Supports VLSM by design • Holds more information about neighbors • Summarize routes. And do it anywhere!!! :D • Reliable packets – uses RTP • Complex metric calculation (DUAL) and loop prevention.

  30. The DUAL algorithm e0/0 e0/0 e1/1 e1/0 e1/1 R5 R4 e1/1 e1/0 e1/1 e0/0 e0/0 e1/0 e1/0 R1 R2 R3 Successor – The best route to a certain network. Feasible Successor – a second best failback route to a destination. Feasible Distance (FD) – Metric of the successor Reported Distance(RD) – Metric reported from the neighbor EIGRP Tables:a) Neighbor Table – Shows neighbors b) Topology Table – EIGRP topology c) Routing Table – The RIB/FIB on the router Feasibility Criteria:RD < FD

  31. Hello! Hello! • Lets bring up EIGRP between R1 and R2. • Basic configuration snippet: router eigrp <AS number> network 192.168.x.0 0.0.0.255 Things that need to match. • AS Number • Authentication (If configured) • K-Values

  32. Merits of EIGRP • Highly scalable if properly designed • Simple to Implement (potential pitfall) • Very Fast convergence due to Feasible successor • Best protocol for a DMVPN scaled network • Supports Stubs • Summarize anywhere • Silent Protocol - Only triggered updates

  33. OSPF - Salient Features • Open standard. • Entire view of the area. • Classless • Summarize only on ABRs and ASBRs • Periodically refreshes the LSAs (30 minutes) • Can be scaled by splitting into areas and summarizing.

  34. OSPF – Working • Brings up neighbor after exchanging hellos • Neighbor table build • Exchanges the LSAs • OSPF Database populated • SPF is run • Routing table is populated • Periodically floods LSAs

  35. OSPF – Things to remember • Support different area types depending on design • Has different types of LSAs • Summary LSA is not summarization • Inter-area traffic passes through the ABR • All areas must connect to backbone (Area 0)

More Related