JN0-643 Question #155: Real Exam Question with Answer & Explanation

You are configuring an EBGP peer in a transit environment. You must advertise routes learned from other EBGP peers in your AS. Any routes originated from within your AS should have a MED of 7000 set. Any routes that originate in AS65222 should be prepended four times. Any routes that transit AS701 should have a MED set to 6. This scenario results in the unintended advertisement of internal 10.0.0.0/8 networks to your peer. user@router> show configuration routing-options autonomous-system 65550; user@router> show configuration protocols bgp group ibgp { type internal; neighbor 10.0.3.5; } group ibgpv6 { type internal; local-address 2001:ffff::3:4; neighbor 2001:ffff::3:5; } group as65010 { family inet { unicast; } family inet6 { unicast; } export as65010-out; peer-as 65010; neighbor 172.16.0.6; } user@router> show configuration policy-options policy-statement as65010-out { term locally-originated { from as-path local-only; then { metric 7000; } } term from-as65222 { from as-path as65222-orig; then as-path-prepend "65550 65550 65550 65550"; } term transit-as701 { from as-path transit-as701; then { metric 6; } } then accept; } as-path local-only "(.)"; as-path as65222-orig ". 65222"; as-path transit-as701 ".* 701 .*"; user@router> show route advertising-protocol bgp 172.16.0.6 inet.0: 43 destinations, 47 routes (43 active, 0 holddown, 0 hidden) Prefix Nexthop MED Lclpref AS path * 10.0.2.0/30 Self 7000 I * 10.0.2.4/30 Self 7000 I * 10.0.2.8/30 Self 7000 I * 10.0.2.16/30 Self 7000 I * 10.0.3.3/32 Self 7000 I * 10.0.3.4/32 Self 7000 I * 10.0.3.5/32 Self 7000 I * 10.0.4.8/30 Self 7000 I * 10.0.8.8/30 Self 7000 I * 10.0.9.9/32 Self 7000 I * 10.255.255.1/32 Self 7000 I * 64.142.88.0/24 Self 7000 I * 130.130.0.0/16 Self 6 65222 46375 701 14203 I * 131.131.131.0/24 Self 6 65222 46375 701 14203 I * 132.132.0.0/25 Self 6 65222 46375 701 32934 I * 133.133.0.0/25 Self 6 65222 46375 701 32934 I * 134.134.0.0/25 Self 65222 46375 14203 I * 135.135.0.0/25 Self 65222 46375 14203 14203 I * 172.16.0.4/30 Self 7000 I * 172.16.0.12/30 Self 7000 I * 172.16.200.0/30 172.16.0.6 7000 I * 192.0.2.0/24 172.16.0.6 7000 I * 192.168.50.0/24 Self 7000 I * 192.168.253.0/24 Self 7000 I * 200.200.0.0/16 172.16.0.6 7000 I * 200.200.0.1/32 172.16.0.6 7000 I * 200.200.1.1/32 172.16.0.6 7000 I * 200.200.200.200/32 172.16.0.6 7000 I inet6.0: 23 destinations, 28 routes (23 active, 0 holddown, 0 hidden) Prefix Nexthop MED Lclpref AS path * ::172.16.0.4/126 Self 7000 I * 2001:1:1::/64 Self 7000 I * 2001:1:2::/64 Self 7000 I * 2001:ffff::3:3/128 Self 7000 I * 2001:ffff::3:4/128 Self 7000 I * 2001:ffff::3:5/128 Self 7000 I * 2001:ffff::9:7/128 Self 7000 I user@router> What caused the accidental advertisement of internal networks to your EBGP peer?