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tech:network:cisco:bgp:bgp:backdoor:backdoor

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tech:network:cisco:bgp:bgp:backdoor:backdoor [2019/02/14 04:01]
wnoguchi
tech:network:cisco:bgp:bgp:backdoor:backdoor [2019/02/14 12:07] (current)
wnoguchi
Line 148: Line 148:
 </​code>​ </​code>​
  
-==== backdoor Configuration ​====+==== Verification ==== 
 + 
 +  * R1 
 + 
 +<​code>​ 
 +traceroute 2.0.0.2 source 1.0.0.1 
 +show ip route 
 +show ip route 2.0.0.2 
 +</​code>​ 
 + 
 +<​code>​ 
 +R1#​traceroute 2.0.0.2 source 1.0.0.1 
 +Type escape sequence to abort. 
 +Tracing the route to 2.0.0.2 
 +VRF info: (vrf in name/id, vrf out name/id) 
 +  1 100.1.3.3 6 msec 4 msec 3 msec 
 +  2 100.2.3.2 6 msec 6 msec 5 msec 
 +R1#show ip route 
 +Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP 
 +       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area  
 +       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 
 +       E1 - OSPF external type 1, E2 - OSPF external type 2 
 +       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 
 +       ia - IS-IS inter area, * - candidate default, U - per-user static route 
 +       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP 
 +       a - application route 
 +       + - replicated route, % - next hop override, p - overrides from PfR 
 + 
 +Gateway of last resort is not set 
 + 
 +      1.0.0.0/32 is subnetted, 1 subnets 
 +C        1.0.0.1 is directly connected, Loopback1 
 +      2.0.0.0/32 is subnetted, 1 subnets 
 +B        2.0.0.2 [20/0] via 100.1.3.3, 01:01:28 
 +      100.0.0.0/8 is variably subnetted, 4 subnets, 2 masks 
 +C        100.1.2.0/​24 is directly connected, GigabitEthernet0/​0 
 +L        100.1.2.1/​32 is directly connected, GigabitEthernet0/​0 
 +C        100.1.3.0/​24 is directly connected, GigabitEthernet0/​1 
 +L        100.1.3.1/​32 is directly connected, GigabitEthernet0/​1 
 +R1#show ip route 2.0.0.2 
 +Routing entry for 2.0.0.2/​32 
 +  Known via "bgp 1", distance 20, metric 0 
 +  Tag 3, type external 
 +  Last update from 100.1.3.3 01:01:46 ago 
 +  Routing Descriptor Blocks: 
 +  * 100.1.3.3, from 100.1.3.3, 01:01:46 ago 
 +      Route metric is 0, traffic share count is 1 
 +      AS Hops 2 
 +      Route tag 3 
 +      MPLS label: none 
 +</​code>​ 
 + 
 +==== Change AD Value (NOT RECOMMENDED) ​====
  
   * R1   * R1
Line 155: Line 207:
 configure terminal configure terminal
 ! !
 +router bgp 1
 +distance bgp 120 200 200
 +exit
 ! !
 end end
Line 164: Line 219:
 configure terminal configure terminal
 ! !
 +router bgp 2
 +distance bgp 120 200 200
 +exit
 ! !
 end end
 </​code>​ </​code>​
  
-  ​* R3+<​code>​ 
 + 
 +R1#conf t   
 +Enter configuration commands, one per line.  End with CNTL/Z. 
 +R1(config)#​router bgp 1 
 +R1(config-router)#​dista 
 +R1(config-router)#​distance bgp ? 
 +  <​1-255> ​ Distance for routes external to the AS 
 + 
 +R1(config-router)#​distance bgp 120 ? 
 +  <​1-255> ​ Distance for routes internal to the AS 
 + 
 +R1(config-router)#​distance bgp 120 200 ? 
 +  <​1-255> ​ Distance for local routes 
 + 
 +R1(config-router)#​distance bgp 120 200 200 
 +R1(config-router)#​ 
 +</​code>​ 
 + 
 +==== Verification ==== 
 + 
 +  ​R1 - R3 
 + 
 +HARD RESET 
 + 
 +<​code>​ 
 +clear ip bgp * 
 +</​code>​ 
 + 
 +  * R1 
 + 
 +<​code>​ 
 +traceroute 2.0.0.2 source 1.0.0.1 
 +show ip route 
 +show ip route 2.0.0.2 
 +show ip protocols | section bgp 
 +show ip protocols | section ospf 
 +show ip bgp 
 +</​code>​ 
 + 
 +<​code>​ 
 +R1#show ip protocols | s bgp 
 +Routing Protocol is "bgp 1" 
 +  Outgoing update filter list for all interfaces is not set 
 +  Incoming update filter list for all interfaces is not set 
 +  IGP synchronization is disabled 
 +  Automatic route summarization is disabled 
 +  Neighbor(s):​ 
 +    Address ​         FiltIn FiltOut DistIn DistOut Weight RouteMap 
 +     ​100.1.3.3 ​                                            
 +    100.1.3.3 ​                                            
 +  Maximum path: 1 
 +  Routing Information Sources: 
 +    Gateway ​        ​Distance ​     Last Update 
 +    100.1.3.3 ​            ​20 ​     01:08:02 
 +  Distance: external 120 internal 200 local 200 
 +R1#show ip protocols | section ospf 
 +Routing Protocol is "ospf 1" 
 +  Outgoing update filter list for all interfaces is not set 
 +  Incoming update filter list for all interfaces is not set 
 +  Router ID 1.0.0.1 
 +  Number of areas in this router is 1. 1 normal 0 stub 0 nssa 
 +  Maximum path: 4 
 +  Routing for Networks: 
 +    1.0.0.1 0.0.0.0 area 0 
 +    100.1.2.1 0.0.0.0 area 0 
 +  Routing Information Sources: 
 +    Gateway ​        ​Distance ​     Last Update 
 +     ​2.0.0.2 ​             110      01:09:48 
 +    2.0.0.2 ​             110      01:09:48 
 +  Distance: (default is 110) 
 +R1#sh ip bgp 
 +BGP table version is 3, local router ID is 1.0.0.1 
 +Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,  
 +              r RIB-failure,​ S Stale, m multipath, b backup-path,​ f RT-Filter,  
 +              x best-external,​ a additional-path,​ c RIB-compressed,​  
 +Origin codes: i - IGP, e - EGP, ? - incomplete 
 +RPKI validation codes: V valid, I invalid, N Not found 
 + 
 +     ​Network ​         Next Hop            Metric LocPrf Weight Path 
 + ​*> ​ 1.0.0.1/​32 ​      ​0.0.0.0 ​                 0         32768 i 
 + ​r> ​ 2.0.0.2/​32 ​      ​100.1.3.3 ​                             0 3 2 i 
 +R1#sh ip ro 
 +Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP 
 +       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area  
 +       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 
 +       E1 - OSPF external type 1, E2 - OSPF external type 2 
 +       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 
 +       ia - IS-IS inter area, * - candidate default, U - per-user static route 
 +       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP 
 +       a - application route 
 +       + - replicated route, % - next hop override, p - overrides from PfR 
 + 
 +Gateway of last resort is not set 
 + 
 +      1.0.0.0/32 is subnetted, 1 subnets 
 +C        1.0.0.1 is directly connected, Loopback1 
 +      2.0.0.0/32 is subnetted, 1 subnets 
 +O        2.0.0.2 [110/2] via 100.1.2.2, 00:03:36, GigabitEthernet0/​0 
 +      100.0.0.0/8 is variably subnetted, 4 subnets, 2 masks 
 +C        100.1.2.0/​24 is directly connected, GigabitEthernet0/​0 
 +L        100.1.2.1/​32 is directly connected, GigabitEthernet0/​0 
 +C        100.1.3.0/​24 is directly connected, GigabitEthernet0/​1 
 +L        100.1.3.1/​32 is directly connected, GigabitEthernet0/​1 
 +R1#​traceroute 2.0.0.2 source 1.0.0.1 
 +Type escape sequence to abort. 
 +Tracing the route to 2.0.0.2 
 +VRF info: (vrf in name/id, vrf out name/id) 
 +  1 100.1.2.2 7 msec 4 msec 4 msec 
 +</​code>​ 
 + 
 +<​code>​ 
 +R2#show ip protocols | s bgp 
 +Routing Protocol is "bgp 2" 
 +  Outgoing update filter list for all interfaces is not set 
 +  Incoming update filter list for all interfaces is not set 
 +  IGP synchronization is disabled 
 +  Automatic route summarization is disabled 
 +  Neighbor(s):​ 
 +    Address ​         FiltIn FiltOut DistIn DistOut Weight RouteMap 
 +     ​100.2.3.3 ​                                            
 +    100.2.3.3 ​                                            
 +  Maximum path: 1 
 +  Routing Information Sources: 
 +    Gateway ​        ​Distance ​     Last Update 
 +    100.2.3.3 ​            ​20 ​     01:08:01 
 +  Distance: external 120 internal 200 local 200 
 +R2#show ip protocols | section ospf 
 +Routing Protocol is "ospf 1" 
 +  Outgoing update filter list for all interfaces is not set 
 +  Incoming update filter list for all interfaces is not set 
 +  Router ID 2.0.0.2 
 +  Number of areas in this router is 1. 1 normal 0 stub 0 nssa 
 +  Maximum path: 4 
 +  Routing for Networks: 
 +    2.0.0.2 0.0.0.0 area 0 
 +    100.1.2.2 0.0.0.0 area 0 
 +  Routing Information Sources: 
 +    Gateway ​        ​Distance ​     Last Update 
 +     ​1.0.0.1 ​             110      01:09:48 
 +    1.0.0.1 ​             110      01:09:48 
 +  Distance: (default is 110) 
 +R2#sh ip bgp 
 +BGP table version is 3, local router ID is 2.0.0.2 
 +Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,  
 +              r RIB-failure,​ S Stale, m multipath, b backup-path,​ f RT-Filter,  
 +              x best-external,​ a additional-path,​ c RIB-compressed,​  
 +Origin codes: i - IGP, e - EGP, ? - incomplete 
 +RPKI validation codes: V valid, I invalid, N Not found 
 + 
 +     ​Network ​         Next Hop            Metric LocPrf Weight Path 
 + ​r> ​ 1.0.0.1/​32 ​      ​100.2.3.3 ​                             0 3 1 i 
 + ​*> ​ 2.0.0.2/​32 ​      ​0.0.0.0 ​                 0         32768 i 
 +</​code>​ 
 + 
 +<​code>​ 
 +R3#show ip protocols | s bgp 
 +Routing Protocol is "bgp 3" 
 +  Outgoing update filter list for all interfaces is not set 
 +  Incoming update filter list for all interfaces is not set 
 +  IGP synchronization is disabled 
 +  Automatic route summarization is disabled 
 +  Neighbor(s):​ 
 +    Address ​         FiltIn FiltOut DistIn DistOut Weight RouteMap 
 +    100.1.3.1 ​                                            
 +     ​100.2.3.2 ​                                            
 +    100.2.3.2 ​                                            
 +  Maximum path: 1 
 +  Routing Information Sources: 
 +    Gateway ​        ​Distance ​     Last Update 
 +    100.2.3.2 ​            ​20 ​     01:08:02 
 +    100.1.3.1 ​            ​20 ​     01:08:02 
 +  Distance: external 20 internal 200 local 200 
 +R3#sh ip bgp 
 +BGP table version is 3, local router ID is 100.2.3.3 
 +Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,  
 +              r RIB-failure,​ S Stale, m multipath, b backup-path,​ f RT-Filter,  
 +              x best-external,​ a additional-path,​ c RIB-compressed,​  
 +Origin codes: i - IGP, e - EGP, ? - incomplete 
 +RPKI validation codes: V valid, I invalid, N Not found 
 + 
 +     ​Network ​         Next Hop            Metric LocPrf Weight Path 
 + ​*> ​ 1.0.0.1/​32 ​      ​100.1.3.1 ​               0             0 1 i 
 + ​*> ​ 2.0.0.2/​32 ​      ​100.2.3.2 ​               0             0 2 i 
 +</​code>​ 
 + 
 +==== backdoor Configuration ==== 
 + 
 +  * R1
  
 <​code>​ <​code>​
 configure terminal configure terminal
 ! !
 +router bgp 1
 +network 2.0.0.2 mask 255.255.255.255 backdoor
 +exit
 ! !
 end end
 +</​code>​
 +
 +  * R2
 +
 +<​code>​
 +configure terminal
 +!
 +router bgp 1
 +network 1.0.0.1 mask 255.255.255.255 backdoor
 +exit
 +!
 +end
 +</​code>​
 +
 +==== Verification ====
 +
 +Reset is not required?
 +
 +  * R1
 +
 +<​code>​
 +traceroute 2.0.0.2 source 1.0.0.1
 +show ip route
 +show ip route 2.0.0.2
 +show ip protocols | section bgp
 +show ip protocols | section ospf
 +show ip bgp
 +</​code>​
 +
 +<​code>​
 +R1#​traceroute 2.0.0.2 source 1.0.0.1
 +Type escape sequence to abort.
 +Tracing the route to 2.0.0.2
 +VRF info: (vrf in name/id, vrf out name/id)
 +  1 100.1.3.3 6 msec 4 msec 4 msec
 +  2 100.2.3.2 7 msec 5 msec 6 msec
 +R1#conf t
 +Enter configuration commands, one per line.  End with CNTL/Z.
 +R1(config)#​router bgp 1
 +R1(config-router)#​netwo
 +R1(config-router)#​network 2.0.0.2 ?
 +  backdoor ​  ​Specify a BGP backdoor route
 +  mask       ​Network mask
 +  route-map ​ Route-map to modify the attributes
 +  <cr>
 +
 +R1(config-router)#​network 2.0.0.2 mas
 +R1(config-router)#​network 2.0.0.2 mas    ​
 +R1(config-router)#​network 2.0.0.2 mask 255.255.255.255 ?
 +  backdoor ​  ​Specify a BGP backdoor route
 +  route-map ​ Route-map to modify the attributes
 +  <cr>
 +
 +R1(config-router)#​network 2.0.0.2 mask 255.255.255.255 bac
 +R1(config-router)#​network 2.0.0.2 mask 255.255.255.255 backdoor ​
 +R1(config-router)#​^Z
 +R1#
 +*Feb 14 12:​02:​04.976:​ %SYS-5-CONFIG_I:​ Configured from console by console
 +R1#sh ip bgp
 +BGP table version is 3, local router ID is 1.0.0.1
 +Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, ​
 +              r RIB-failure,​ S Stale, m multipath, b backup-path,​ f RT-Filter, ​
 +              x best-external,​ a additional-path,​ c RIB-compressed, ​
 +Origin codes: i - IGP, e - EGP, ? - incomplete
 +RPKI validation codes: V valid, I invalid, N Not found
 +
 +     ​Network ​         Next Hop            Metric LocPrf Weight Path
 + ​*> ​ 1.0.0.1/​32 ​      ​0.0.0.0 ​                 0         32768 i
 + ​r> ​ 2.0.0.2/​32 ​      ​100.1.3.3 ​                             0 3 2 i
 +R1#sh ip ro
 +Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
 +       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
 +       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
 +       E1 - OSPF external type 1, E2 - OSPF external type 2
 +       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
 +       ia - IS-IS inter area, * - candidate default, U - per-user static route
 +       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
 +       a - application route
 +       + - replicated route, % - next hop override, p - overrides from PfR
 +
 +Gateway of last resort is not set
 +
 +      1.0.0.0/32 is subnetted, 1 subnets
 +C        1.0.0.1 is directly connected, Loopback1
 +      2.0.0.0/32 is subnetted, 1 subnets
 +O        2.0.0.2 [110/2] via 100.1.2.2, 00:00:48, GigabitEthernet0/​0
 +      100.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
 +C        100.1.2.0/​24 is directly connected, GigabitEthernet0/​0
 +L        100.1.2.1/​32 is directly connected, GigabitEthernet0/​0
 +C        100.1.3.0/​24 is directly connected, GigabitEthernet0/​1
 +L        100.1.3.1/​32 is directly connected, GigabitEthernet0/​1
 +R1#sh ip ro 2.0.0.2
 +Routing entry for 2.0.0.2/32
 +  Known via "ospf 1", distance 110, metric 2, type intra area
 +  Last update from 100.1.2.2 on GigabitEthernet0/​0,​ 00:01:12 ago
 +  Routing Descriptor Blocks:
 +  * 100.1.2.2, from 2.0.0.2, 00:01:12 ago, via GigabitEthernet0/​0
 +      Route metric is 2, traffic share count is 1
 +R1#sh ip bgp 2.0.0.2
 +BGP routing table entry for 2.0.0.2/32, version 3
 +Paths: (1 available, best #1, table default, RIB-failure(17) - next-hop mismatch)
 +  Not advertised to any peer
 +  Refresh Epoch 1
 +  3 2
 +    100.1.3.3 from 100.1.3.3 (100.2.3.3)
 +      Origin IGP, localpref 100, valid, external, best
 +      rx pathid: 0, tx pathid: 0x0
 +R1#​traceroute 2.0.0.2 source 1.0.0.1
 +Type escape sequence to abort.
 +Tracing the route to 2.0.0.2
 +VRF info: (vrf in name/id, vrf out name/id)
 +  1 100.1.2.2 5 msec 5 msec 4 msec
 +R1#
 </​code>​ </​code>​
  
tech/network/cisco/bgp/bgp/backdoor/backdoor.1550116872.txt.gz · Last modified: 2019/02/14 04:01 by wnoguchi