Entire Site
Free Trial
Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.
- Create BookmarkCreate Bookmark
- Create Note or TagCreate Note or Tag
- PrintPrint
Chapter 1. Practice Lab > Section 3: BGP
Section 3: BGP
| Q: | Is it okay to disable autosynchronization in BGP? |
| A: | You must determine whether you need this feature on or off. Remember that you should have synchronization on only when you are fully redistributing between BGP and your IGP. |
| Q: | I find that when the Frame Relay network fails, my neighbor relationship is still maintained between R2 and R5. This is because the loopback routes are still available over the alternative path through the network. Can I block my loopbacks or policy route at some point to effectively break the peering? |
| A: | You need to effectively break the peering, but you can use a far simpler method to achieving this, one that still maintains unaltered communication between R2 and R5. Think about what you need to configure when you have eBGP peers. |
| Q: | I might have been a little generous with my original multi-hop value between R2 and R5. I can break the peering if I reduce this down to a Time To Live (TTL) of 2. Is this okay? |
| A: | Yes. |
| Q: | I think I can stop the loopback on R2 being advertised by using the community value of no-export, but if I enable this to R2, wouldn’t it make it to R5 even when the Frame Relay is working? |
| A: | It wouldn’t be advertised to R5 AS300 from R2. You just have to think about whether R2 is the best place to send the community to originally. |
| Q: | For the HSRP question, is this some form of conditional advertising? |
| A: | No, the clue is in the question; just find a way of tracking the BGP route and manipulate the HSRP process. |
| Q: | So if I enable IP SLA to track a route in the routing table, I can use this to control HSRP? |
| A: | Yes. |
| Q: | You haven’t told me what address I should use for HSRP. Is it okay to use the first address in the subnet? |
| A: | Yes. |
| Q: | I have configured my two new loopbacks. Can I use two route maps inbound from R1 and R2 both pointing to different ACLs so that each route map only calls one ACL? |
| A: | No, you still have two ACLs. |
| Q: | Can I set community values on the routes and match on these using a single ACL? |
| A: | No, you are instructed to use an ACL; your solution would require additional configuration. |
| Q: | Can I use a prefix list to achieve this? |
| A: | No, you are instructed to use an ACL. |
| Q: | So, I need an ACL with a mask that is suitable for both ranges? |
| A: | Not necessarily. You only need to match one requirement on the permit functionality; the other could be met by deny. |
