CCDA FAQ: OSPF, BGP, Route Manipulation, and IP Multicast Q1. True or false: A router needs to have all its interfaces in Area 0 to be considered an OSPF backbone router. Answer: False. A router with one or more interfaces in Area 0 is considered an OSPF backbone router. Q2. True or false: OSPF IS-IS uses a designated router in multiaccess networks. Answer: True Q3. Which … [Read more...]
How to enable Graceful Restart in AutoVPN with BGP
This article explains how to configure Graceful Restart in AutoVPN with BGP. An AutoVPN solution with the BGP routing protocol uses the "Unconfigured BGP Peers" feature to allow the dynamic addition of Spokes without the need to reconfigure the Hub. A special allow statement is used in the BGP configuration, specifying the IP range used by Spokes. Any newly added Spoke … [Read more...]
BGP route selection doesnt respect local preference
This article outlines the problem of BGP route selection broken in certain code version and how could one find that they are affected. In 9.3 and 9.4, due to an uninitialized variable being used to select the best route among all routes for the same prefix, random route selection may happen. This may lead a bgp running router to select the route with lowest local … [Read more...]
Sample Configuration of eBGP and iBGP(Border Gateway Protocol) on EX series switches
This article provides the configuration eBGP(External BGP) and iBGP(Internal BGP) on EX series switches Topology: [crayon-5e8164fbd026e635999065/] The following is the configuration on all the four switches: [crayon-5e8164fbd0277062877249/] … [Read more...]
ISP Failover: Configure J-Series/SRX for dual ISP without dynamic routing protocols
This article contains a sample configuration for J-Series and SRX Branch with dual ISP connection. This will allow for ISP failover without dynamic routing protocols such as OSPF or BGP. Topology Assumptions Trust zone network is 192.168.1.0/24 on ge-0/0/0 DMZ zone network is 10.10.10.0/24 on ge-0/0/1 ISP1 zone network is 1.1.1.0/29 on fe-0/0/6 ISP2 zone network is … [Read more...]
MPLS BGP VPN’s not supported accross un-numbered interfaces
MPLS BGP VPN's not supported across un-numbered interfaces. When using an un-numbered interface between PE and P routers instead of IP numbered interfaces, the ERX no longer displays VPN routes and shows the next hop address and unreachable even though ICMP Pings to the next hop address are successful. Platform: Juniper … [Read more...]