- Cisco mpls fundamentals pdf how to#
- Cisco mpls fundamentals pdf pdf#
- Cisco mpls fundamentals pdf verification#
You can form IBGP connection between any Router A / Router C/ Router G which are sitting 20 hops away and not direction is required. Better option is to configure IBGP within those 100 routers and have reachability to any loopbacks across the network. You can also have static routes but if you look at within a autonomous system environment having 100s of routers, it is not really a scalable way to run a static route everywhere. When you are using the peering via loopback address, you need to have the loopback reachability these IBGP provides the loopback to loopback reachability. Why we are using OSPF and iBGP both are same IGP?Ī: If you notice the IBGP configuration we did the peering. It becomes the route when it is selected as the best and installed in the routing table. What does mean of "Prefix" in BGP?Ī: Prefix is something that is advertised to a peer. Apart from that it’s not really required for forming any kind of BGP neighboring.
Cisco mpls fundamentals pdf how to#
It’s a good practice to configure loop back addresses as router id and that has been recommended also so that you know how to reach particular router within the network. What is the role of router id in BGP?Ī: Router id really helps kind of making uniquely identify particular information while at the same time it has some information that is exchanged between the routers. Can we advertise subnets less than /24 ?Ī: Yes, we can. What is the use of MED?Ī: Use of MED, its kind of metrics like we have in IGP, its again used as an attribute and used to influence traffic e between different AS. What is the preference level in all filtering methodĪ: - this is how path selection works. AS path prepend can be used to add extra AS path on less preferred path as shorter is preferred. We can influence outbound traffic.Ī: You can use route-map to set as path prepend or modify MED value (lower the better) to influence routing. What is the best way to influence inbound traffic? In our organization outbound Netflix traffic leaves the higher bandwidth interface and is inbound on our lower bandwidth interface. for ospf you have to ensure you are advertising desired networks and they are in ospf database "show ip ospf database" Q. We have ospf internal and bgp external - could we have some troubleshooting commands to see each customer receive routes please?Ī: For bgp : show ip bgp neigh x.x.x.x receive routes and show ip bgp neigh x.x.x.x adv routes. so send-community is used to send that info out for provider to recognize it and take action if any. What is use of send-community cmd in BGP?Ī: ISP can distinguish routes from various customers and apply policies accordingly, its easy way to recognize bunch of routes collectively. Can we use bfd over bgp to improve convergence time?Ī: Yes, and here is good doc for the same Q.
Cisco mpls fundamentals pdf verification#
automatically, what could be the issue here?Ī: 1) 2) debug ip bgp 3) ensure route to neighbor is not flapping 4) layer 1 issue/ match config with provider 5) high cpu verification are good starting I have a question, at CE end ASR9k & i'm not aware of PE end, my bgp session is being established but gets disconnected after 90 sec. higher the better and default value is 100. In the BGP route-map example, what is the local-preference attribute used for?Ī: Local preference helps determine which path to choose for exiting should you have multi path available. Do you have any quick troubleshooting commands ? it means you can redistribute eigrp/rip etc into bgp, so the command ipv4 unicast prepares the router for this capability Are the Open packets the equivalent to the TCP 3-way handshake?Ī: Yes, BGP uses tcp port 179 to communicate with neighbor and 3 way handshake is underline mechanism.Ī: BGP supports multiprotocol. In IGP you can influence egress routes but no knob to influence neighbor's decision. Why we need IBGP however IGP can also serve the same?Ī: BGP is open standard, scalable, and available attributes helps tweak incoming and outgoing traffic. see this link it has very useful info, let me know for any follow up question/put it on the community. What values can we set for SPD, Input Queues and small buffers in heavy bgp environments?Ī. The complete recording of this live Webcast can be accessed here.īorder Gateway Protocol (BGP) Fundamentals and Troubleshooting The related Ask The Expert sessions is available here.
Cisco mpls fundamentals pdf pdf#
You can download the slides of the presentation in PDF format here.