OSPF Layer 3 redundancy does not follow Layer 1 redundancy. When designing and troubleshooting networks, you need to keep in mind how OSPF areas function. As I discussed in Discontiguous non-Area 0 Areas in OSPF , while discontiguous non-Area 0 areas can be supported as a short term measure, this is not a good long term design for production
Layer 3—OSPF Network Redundancy— Rapid Convergence Open shortest path first (OSPF) is an intradomain, link-state routing protocol. The main idea of OSPF is that each OSPF router is able to determine the state of the link to all neighbor routers and the associated costs. OSPF Layer 3 redundancy does not follow Layer 1 redundancy. When designing and troubleshooting networks, you need to keep in mind how OSPF areas function. As I discussed in Discontiguous non-Area 0 Areas in OSPF , while discontiguous non-Area 0 areas can be supported as a short term measure, this is not a good long term design for production OSPF with redundancy https://ibb.co/108c8Jx I have configured GRE tunnel between all routers to each other router except those in the same network (sales 1 to sales 2 for example). Two ABRs between two OSPF areas for redundancy There are some resources that suggest that to simplify OSPF that you have only a single ABR per area. And some discussions of OSPF stub and totally stub suggest having a single ABR for an OSPF area. I do not agree with these.
OSPF is enabled (L3 switch) in (Site A), so all networks of (site A) will be advertised and see all other sites through MPLS. >>>> No issues and works like a charm! Case 2: (Failover to Firewall) In case of P2P is down, OSPF will not take an effect and traffic from Site A to Sites B, C, and D will go through Firewall, Site X will not be visible
Mar 21, 2015 · This video demonstrates on how to configure cisco routers for dual wan redundancy or changing route automatically using ip sla. OSPF Load Balancing and Tweaking - Duration: 16:25. Keith Barker Open Shortest Path First (OSPF) is an interior gateway protocol that multicasts the routing information to all the hosts within a single network. It sends routing information to all the routers in the network by calculating the shortest path to each router on the basis of the structure built up by each router.
Feb 12, 2018 · NSF always runs with SSO and provides redundancy for Layer 3 traffic. NSF is supported by the BGP, OSPF, and EIGRP routing protocols and is supported by Cisco Express Forwarding (CEF) for forwarding.
Jan 15, 2020 · How to Configure OSPF Routing on Cisco Router with Packet Tracer. OSPF is a routing protocol used in WAN or business networks. This routing protocol maps the entire network using the SPF algorithm and provides a fast convergence as a result of a failure on a Router on the network. Summary. Sub-menu level: /interface vrrp Standards: RFC 5798, RFC 3768 This chapter describes the Virtual Router Redundancy Protocol (VRRP) support in RouterOS. Mostly on larger LANs dynamic routing protocols (OSPF or RIP) are used, however there are number of factors that may make undesirable to use dynamic routing protocols.