BGP

An enterprise network has two routers, R1 and R2, both running BGP. R1 is an eBGP speaker with ISP1, and R2 is an eBGP speaker with ISP2. Both routers are in the same AS 65000. The engineer wants to ensure that traffic from the enterprise to the Internet prefers the path through ISP1 when both links are up. R1 learns a default route from ISP1, and R2 learns a default route from ISP2. Which BGP attribute should the engineer modify on R1 to influence outbound traffic selection?

A network engineer is troubleshooting BGP peering between two routers in different autonomous systems. The peering is established over a directly connected Ethernet link. The engineer notices that the BGP session is flapping every few minutes. The configuration on both routers appears correct, and the IP connectivity is stable. The engineer checks the BGP logs and sees messages like 'BGP-3-NOTIFICATION: sent 4/0 (Hold Timer Expired)'. What is the most likely cause of this issue?

A network engineer is configuring BGP on a Cisco router that is part of an enterprise network with multiple BGP peers. The router receives routes from two different ISPs. The engineer wants to ensure that only specific prefixes from ISP-A are installed in the routing table, while all other routes from ISP-A are ignored. Additionally, the engineer wants to accept all routes from ISP-B. Which BGP feature should be used on the router for the peering with ISP-A?

An enterprise has two BGP routers, R1 and R2, both in AS 65000. R1 peers with ISP1 (AS 100) and R2 peers with ISP2 (AS 200). The enterprise advertises a prefix 192.168.0.0/24 to both ISPs. The engineer wants to ensure that traffic from the Internet to this prefix enters the network primarily via R1, and only uses R2 if the link to ISP1 fails. Which BGP attribute should be manipulated on the updates sent to the ISPs?

A network engineer is configuring BGP on a Cisco router that connects to two ISPs. The router has a default route pointing to each ISP. The engineer wants to load balance outbound traffic across both ISPs. The router receives a default route from both ISPs. Which BGP configuration approach will allow the router to install both default routes in the routing table and load balance traffic?

An engineer is configuring BGP on a router that will act as a route reflector to reduce iBGP peering requirements. The router has several iBGP peers. The engineer wants to ensure that the route reflector does not modify the next-hop attribute of routes it reflects to its clients. Which configuration command should the engineer use?

A network engineer is troubleshooting a BGP issue where a router is not installing a specific prefix in its routing table, even though the prefix is present in the BGP table. The engineer runs 'show ip bgp 10.0.0.0/24' and sees that the route is valid but not best. The BGP table shows that the route has a higher local preference than the current best path, but the AS_PATH is longer. What is the most likely reason the route is not being selected as best?

An enterprise network uses BGP to connect to two ISPs. The router has a BGP configuration that includes the command 'bgp bestpath med missing-as-worst'. The engineer notices that routes from ISP-A that do not have the MED attribute are being preferred over routes from ISP-B that have a MED of 50. What is the effect of the 'bgp bestpath med missing-as-worst' command?

A network engineer is configuring BGP on a router that will be used for BGP route summarization. The router receives multiple more-specific prefixes from its eBGP peers. The engineer wants to advertise a summary route to the iBGP peers without advertising the more-specific routes. Which command should the engineer use to suppress the more-specific routes while still installing them in the local routing table?

A network engineer runs the following command on Router R1: R1# show bgp summary BGP router identifier 10.0.0.1, local AS number 65001 BGP table version is 14, main routing table version 14 4 network entries using 1152 bytes of memory 4 path entries using 320 bytes of memory 2/1 BGP path/bestpath attribute entries using 560 bytes of memory 0 BGP route reflector client to client reflections 2 BGP community entries using 80 bytes of memory Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 10.0.1.2 4 65002 2345 2346 14 0 0 00:12:34 3 10.0.1.3 4 65003 1234 1235 14 0 0 00:08:21 2 10.0.1.4 4 65004 567 568 14 0 0 00:05:45 0 Based on this output, what can be concluded?

A network engineer runs the following command on Router R1: R1# show bgp ipv4 unicast 192.168.1.0 BGP routing table entry for 192.168.1.0/24, version 10 Paths: (2 available, best #2, table default) Advertised to update-groups: 1 Refresh Epoch 1 Local 10.0.0.2 from 10.0.1.2 (10.0.0.2) Origin IGP, metric 0, localpref 100, valid, internal rx pathid: 0, tx pathid: 0x0 Local, (received & used) 10.0.0.3 from 10.0.1.3 (10.0.0.3) Origin IGP, metric 0, localpref 200, valid, internal, best rx pathid: 0, tx pathid: 0x0 Based on this output, what can be concluded?

A network engineer runs the following command on Router R1: R1# show bgp ipv4 unicast summary | include 10.0.1.5 10.0.1.5 4 65005 3456 3457 15 0 0 00:15:22 5 Based on this output, what can be concluded?

A network engineer runs the following command on Router R1: R1# show bgp ipv4 unicast 10.10.10.0 BGP routing table entry for 10.10.10.0/24, version 20 Paths: (2 available, best #1, table default) Advertised to update-groups: 1 Refresh Epoch 1 65050 65100 10.0.1.2 from 10.0.1.2 (10.0.0.2) Origin IGP, metric 0, localpref 100, weight 0, valid, external, best rx pathid: 0, tx pathid: 0x0 65050 65100 65200 10.0.1.3 from 10.0.1.3 (10.0.0.3) Origin IGP, metric 0, localpref 100, weight 0, valid, external rx pathid: 0, tx pathid: 0x0 Based on this output, what can be concluded?

A network engineer runs the following command on Router R1: R1# show bgp ipv4 unicast neighbors 10.0.1.2 received-routes Network Next Hop Metric LocPrf Weight Path *> 192.168.1.0/24 10.0.1.2 0 100 0 65050 i *> 192.168.2.0/24 10.0.1.2 0 100 0 65050 i *> 10.10.10.0/24 10.0.1.2 0 100 0 65050 65100 i Total number of prefixes 3 Based on this output, what can be concluded?

A network engineer runs the following command on Router R1: R1# show bgp ipv4 unicast neighbors 10.0.1.2 advertised-routes Network Next Hop Metric LocPrf Weight Path *> 172.16.0.0/16 10.0.1.1 0 100 0 i *> 172.16.1.0/24 10.0.1.1 0 100 0 i Total number of prefixes 2 Based on this output, what can be concluded?

A network engineer runs the following command on Router R1: R1# show bgp ipv4 unicast 192.168.1.0/24 BGP routing table entry for 192.168.1.0/24, version 15 Paths: (1 available, best #1, table default) Advertised to update-groups: 1 Refresh Epoch 1 65050, (received & used) 10.0.1.2 from 10.0.1.2 (10.0.0.2) Origin IGP, metric 0, localpref 100, weight 0, valid, external, best rx pathid: 0, tx pathid: 0x0 Based on this output, what can be concluded?

A network engineer runs the following command on Router R1: R1# show bgp ipv4 unicast neighbors 10.0.1.2 BGP neighbor is 10.0.1.2, remote AS 65050, external link BGP version 4, remote router ID 10.0.0.2 BGP state = Established, up for 00:23:45 Last read 00:00:15, last write 00:00:10, hold time is 90, keepalive interval is 30 seconds Neighbor sessions: 1 active, is not multisession capable Neighbor capabilities: Route refresh: advertised and received(new) Four-octets ASN: advertised and received Address family IPv4 Unicast: advertised and received Enhanced Refresh: advertised and received Multisession: advertised Message statistics: InQ depth is 0 OutQ depth is 0 Sent Rcvd Opens: 1 1 Notifications: 0 0 Updates: 5 3 Keepalives: 47 48 Route Refresh: 0 0 Total: 53 52 Default minimum time between advertisement runs is 30 seconds Based on this output, what can be concluded?

A network engineer runs the following command on Router R1: R1# show bgp ipv4 unicast 10.0.0.0/8 BGP routing table entry for 10.0.0.0/8, version 25 Paths: (2 available, best #2, table default) Advertised to update-groups: 1 Refresh Epoch 1 65050 65100 10.0.1.2 from 10.0.1.2 (10.0.0.2) Origin IGP, metric 0, localpref 100, weight 0, valid, external rx pathid: 0, tx pathid: 0x0 65050 10.0.1.3 from 10.0.1.3 (10.0.0.3) Origin IGP, metric 0, localpref 100, weight 0, valid, external, best rx pathid: 0, tx pathid: 0x0 Based on this output, what can be concluded?

router bgp 65000 bgp router-id 10.0.0.1 neighbor 10.0.0.2 remote-as 65001 neighbor 10.0.0.2 route-map SET_COMMUNITY in ! route-map SET_COMMUNITY permit 10 set community 100:200 ! What is the effect of this configuration?

router bgp 65000 bgp router-id 10.0.0.1 neighbor 10.0.0.2 remote-as 65000 ! Which statement about this configuration is true?

router bgp 65000 bgp router-id 10.0.0.1 neighbor 10.0.0.2 remote-as 65001 neighbor 10.0.0.2 ebgp-multihop 2 neighbor 10.0.0.2 update-source Loopback0 ! What is the purpose of the ebgp-multihop 2 command?

router bgp 65000 bgp router-id 10.0.0.1 neighbor 10.0.0.2 remote-as 65001 neighbor 10.0.0.2 route-map FILTER in ! route-map FILTER deny 10 match ip address prefix-list BLOCKED route-map FILTER permit 20 ! ip prefix-list BLOCKED seq 5 permit 10.0.0.0/8 ! What is the effect of this configuration?

router bgp 65000 bgp router-id 10.0.0.1 neighbor 10.0.0.2 remote-as 65001 neighbor 10.0.0.2 route-map SET_MED out ! route-map SET_MED permit 10 set metric 50 ! What is the effect of this configuration on routes advertised to 10.0.0.2?

router bgp 65000 bgp router-id 10.0.0.1 neighbor 10.0.0.2 remote-as 65001 neighbor 10.0.0.2 route-map SET_ORIGIN in ! route-map SET_ORIGIN permit 10 set origin incomplete ! What is the effect of this configuration?

What is the default value of the BGP 'weight' attribute for routes learned from a neighbor?

Which BGP attribute is used to indicate the degree of preference for a route within an AS and is propagated to all iBGP peers?

In BGP best path selection, which of the following is compared first?

Drag and drop the steps of BGP session establishment between eBGP peers into the correct order, from first to last.

Drag and drop the steps of BGP best path selection process into the correct order, from first to last.

Drag and drop the steps of configuring an iBGP route reflector cluster into the correct order, from first to last.

Drag and drop the steps of iBGP route reflection configuration steps into the correct order, from first to last.

Drag and drop the steps of BGP route aggregation and suppress-map process into the correct order, from first to last.

Drag and drop the steps of BGP confederations setup between sub-ASes into the correct order, from first to last.

Drag and drop the steps of BGP policy application (route-map, prefix-list, AS-path ACL) into the correct order, from first to last.

Drag and drop the steps of BGP graceful restart negotiation steps into the correct order, from first to last.

Drag and drop the steps of iBGP route reflection configuration into the correct order, from first to last.

Drag and drop the steps of BGP route aggregation and suppress-map process into the correct order, from first to last.

Drag and drop the steps of BGP confederations setup between sub-ASes into the correct order, from first to last.

Drag and drop the steps of BGP policy application (route-map, prefix-list, AS-path ACL) into the correct order, from first to last.

Drag and drop the steps of BGP graceful restart negotiation steps into the correct order, from first to last.

Drag and drop each BGP attribute on the left to its matching type on the right.

Drag and drop each BGP message type on the left to its matching function on the right.

Drag and drop each BGP path selection criterion on the left to its order of preference (1 = highest priority) on the right.

Drag and drop each BGP attribute on the left to its preferred value (highest or lowest) on the right.

Drag and drop each BGP community on the left to its standard behavior on the right.

Drag and drop each BGP attribute on the left to its matching attribute type on the right.

Drag and drop each BGP message type on the left to its matching function on the right.

Drag and drop each BGP path selection criterion on the left to its correct order of preference (1 = highest priority) on the right.

Drag and drop each BGP attribute on the left to the value that is preferred (highest or lowest) during path selection on the right.

Drag and drop each BGP community on the left to its standard behavior on the right.

Which two statements about BGP path attributes are true? (Choose two.)

Which two statements about BGP route selection are true? (Choose two.)

Which three statements about BGP peering are true? (Choose three.)

Which three statements about BGP route reflectors are true? (Choose three.)

Which two statements about BGP path attributes are true? (Choose two.)

Which three statements about BGP route selection are true? (Choose three.)

Which two statements about BGP neighbor states are true? (Choose two.)

Which three statements about BGP route reflectors are true? (Choose three.)