Category Archives: OSPF

OSPF

Palo Alto Networks: OSPF and L3 Link aggregation

Posted on December 21, 2012 by

The previous post about Cisco VSS is to integrate with Palo Alto Firewalls. Layer 3 link aggregation on PA firewall Click on Network tab and select Interfaces from the menu on the left. There is an “Add Aggregate Group” at … Continue reading →

Posted in Firewall, OSPF, Route, Security | Tagged , , , , | 4 Comments

MPLS: OSPF sham-links

Posted on June 1, 2012 by

Introduction The provider’s MPLS cloud has three routers namely – R1 (P-router), R2 (PE-R2) and R3 (PE-R3). These routers formed OSPF adjacency with one another. R2 and R3 are iBGP neighbors peering with each other’s loopback address. The TTL propagation … Continue reading →

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MPLS Layer 3 VPN

Posted on May 24, 2012 by

Acknowledgement Without MR.Keith Barker’s 21 minutes video instruction, constructing MPLS VPN lab will take a longer time. His 21 minutes video instruction summarizes all. MR. Keith Barker has amazing skills to translate complicated concepts into simpler and easier to understand … Continue reading →

Posted in BGP, MPLS, OSPF, Route, WAN | Tagged , , , , , | Leave a comment

Configuration examples with quagga

Posted on May 12, 2012 by

I have heard of Quagga for sometime but I had never tried it until now. Quagga was installed on my old Core duo, 2GB laptop. Quagga is a suite of routing daemons, the suite contains these daemons: 1. ospfd – … Continue reading →

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Type 10 LSA – Opaque LSA

Posted on April 2, 2012 by

This LSA is an extension of OSPF. The extension is for doing OSPF traffic engineering. MAX-LSA – Protects against adjacent router’s excessive LSA in the OSPF domain. Excessive LSA will cost router’s high cpu resources. This is to limit the … Continue reading →

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LSA types

Posted on April 2, 2012 by

1. Router LSA – This LSA is produced by every router. The LSA contains information of the router’s connected interfaces, states, neighbour router type, any known ospf routers connected to the router’s link and outgoing cost of each link. This … Continue reading →

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Building OSPF adjacency

Posted on April 1, 2012 by

Database Description Packet (DDP) – This contains the summary of all the LSAs, it only contains the headers and not the complete LSA. This allows router to see if its own link state database is updated. This is type 2 … Continue reading →

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OSPF finite state machine

Posted on April 1, 2012 by

Reference: Routing TCP/IP 2nd Edition Jeff Doyle, page 353-357. OSPF router goes through several states before adjacency is formed. DOWN – No hello packets was seen from the neighbour router since the last dead interval. If an OSPF router goes … Continue reading →

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Understanding OSPF

Posted on April 1, 2012 by

Open Shortest Path First is using Djikstra’s shortest path first algorithm. It is a link-state routing protocol, another link-state routing protocol is Intermediate System to Intermediate System also known as IS-IS. General facts about OSPF 1. Uses its own transport … Continue reading →

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OSPF over NBMA

Posted on June 29, 2011 by

R2 hub router interface Serial1/0  no ip address  encapsulation frame-relay  serial restart-delay 0 interface Serial1/0.102 point-to-point  ip address 10.10.10.1 255.255.255.252  frame-relay interface-dlci 102 end interface Serial1/0.103 multipoint  ip address 192.168.100.1 255.255.255.248  ip ospf priority 10  frame-relay interface-dlci 103  frame-relay interface-dlci … Continue reading →

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