{"id":484,"date":"2020-03-29T17:10:00","date_gmt":"2020-03-29T08:10:00","guid":{"rendered":""},"modified":"2020-10-02T22:28:00","modified_gmt":"2020-10-02T13:28:00","slug":"bfd%e3%81%a7%e9%ab%98%e9%80%9f%e5%88%87%e6%9b%bf","status":"publish","type":"post","link":"https:\/\/wp.zassoul.com\/?p=484","title":{"rendered":"BFD\u3067\u9ad8\u901f\u5207\u66ff"},"content":{"rendered":"

\u901a\u5e38\uff0c\u30c0\u30a4\u30ca\u30df\u30c3\u30af\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u3092\u5229\u7528\u3057\u3066\u7d4c\u8def\u306e\u5207\u308a\u66ff\u308f\u308a\u3092\u5236\u5fa1\u3059\u308b\u5834\u5408\uff0c\u30bf\u30a4\u30de\u30fc\u306e\u5024\u3092\u8abf\u6574\u3057\u3066\u884c\u3044\u307e\u3059\u304c\uff0c\u305b\u3044\u305c\u3044\u79d2\u5358\u4f4d\u3067\u306e\u5207\u308a\u66ff\u308f\u308a\u304c\u9650\u754c\u3067\u3059\uff0e<\/p>\n

BFD\uff08Bidirectional Forwarding Detection\uff09\uff08\u53cc\u65b9\u5411\u8ee2\u9001\u691c\u51fa\uff09\u3092\u4f7f\u3046\u3068msec\u5358\u4f4d\u3067\u306e\u9ad8\u901f\u306a\u7d4c\u8def\u5207\u308a\u66ff\u3048\u304c\u53ef\u80fd\u306b\u306a\u308b\u3068\u3044\u3046\u3053\u3068\u3067\uff0c\u691c\u8a3c\uff0e<\/p>\n

https:\/\/tools.ietf.org\/html\/rfc5880<\/a><\/p>\n

BDF\u306b\u306f2\u3064\u306e\u30e2\u30fc\u30c9\u304c\u3042\u308b\uff0e
\u3072\u3068\u3064\u306fAsynchronous mode\uff0e
\u5b9a\u671f\u7684\u306bBFD\u30b3\u30f3\u30c8\u30ed\u30fc\u30eb\u30d1\u30b1\u30c3\u30c8\u3092\u9001\u51fa\u3057\uff0c\u5bfe\u5411\u5074\u3067\u53d7\u4fe1\u3055\u308c\u306a\u304f\u306a\u3063\u305f\u3089\uff0c\u30bb\u30c3\u30b7\u30e7\u30f3\u30c0\u30a6\u30f3\u3068\u306a\u308b\uff0e\uff08\u5bfe\u5411\u5074\u3067\u30c0\u30a6\u30f3\u3068\u691c\u77e5\u3059\u308b\uff09
\u4e8c\u3064\u76ee\u306fDemand mode\uff0e
\u3053\u306e\u30e2\u30fc\u30c9\u306f\u4e00\u5ea6BFD\u30bb\u30c3\u30b7\u30e7\u30f3\u304c\u78ba\u7acb\u3055\u308c\u308b\u3068\uff0c\u5bfe\u5411\u3078\u306eBFD\u30b3\u30f3\u30c8\u30ed\u30fc\u30eb\u30d1\u30b1\u30c3\u30c8\u306e\u9001\u51fa\u3092\u6b62\u3081\u308b\uff0e<\/p>\n

\u691c\u8a3c\u3067\u4f7f\u3063\u305fIOS\u3067\u306fDemand\u30e2\u30fc\u30c9\u306e\u8a2d\u5b9a\u306f\u306a\u3055\u305d\u3046\u3060\u3063\u305f\uff0e\u306a\u306e\u3067\uff0cAsynchorous Mode\u3067\u52d5\u304f\uff0e<\/p>\n

\u8a2d\u5b9a\u306f\u52d5\u304b\u3059\u3060\u3051\u306a\u3089\u51c4\u304f\u7c21\u5358\uff0e<\/p>\n

1\uff0e\u30a4\u30f3\u30bf\u30d5\u30a7\u30fc\u30b9\u306bBFD\u306e\u5b9a\u7fa9\u3092\u5165\u308c\u308b
2\uff0eBFD\u3092\u9069\u7528\u3055\u305b\u308b\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u30d7\u30ed\u30c8\u30b3\u30eb\u3078\u8a2d\u5b9a\u3059\u308b<\/p>\n

\u4ee5\u4e0a\u306e2\u30b9\u30c6\u30c3\u30d7\uff0e<\/p>\n

\u7c21\u5358\u306a\u69cb\u6210\u3092\u7d44\u3093\u3067\u52d5\u304b\u3059\uff0e<\/p>\n

<\/a><\/div>\n

\u307e\u305a\u306f\u666e\u901a\u306bBGP\u3067\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u306e\u8a2d\u5b9a.
\u30c6\u30b9\u30c8\u74b0\u5883\u3067\u306fkeepalive 5, holddown 15\u3068\u3057\u305f\uff0e<\/p>\n

R1\u629c\u7c8b <\/p>\n

router bgp 64512
 bgp log-neighbor-changes
 network 10.10.10.0 mask 255.255.255.0
 network 192.168.1.0
 timers bgp 5 15
 neighbor 10.10.10.2 remote-as 64513
 neighbor 192.168.1.3 remote-as 64512
 neighbor 192.168.1.3 next-hop-self
!
<\/pre>\n
R2\u629c\u7c8b <\/p>\n
router bgp 64512
 bgp log-neighbor-changes
 network 10.10.20.0 mask 255.255.255.0
 network 192.168.1.0 route-map ATTACH_MED
 timers bgp 5 15
 neighbor 10.10.20.2 remote-as 64513
 neighbor 192.168.1.2 remote-as 64512
 neighbor 192.168.1.2 next-hop-self
!
!
ip access-list standard BGP_MED
 permit 192.168.1.0 0.0.0.255
!
!
route-map ATTACH_MED permit 10
 match ip address BGP_MED
 set metric 10
!
<\/pre>\n
R3\u629c\u7c8b <\/p>\n
router bgp 64513
 bgp log-neighbor-changes
 network 10.10.10.0 mask 255.255.255.0
 network 192.168.2.0
 timers bgp 5 15
 neighbor 10.10.10.1 remote-as 64512
 neighbor 192.168.2.3 remote-as 64513
 neighbor 192.168.2.3 next-hop-self
!
<\/pre>\n
R4\u629c\u7c8b <\/p>\n
router bgp 64513
 bgp log-neighbor-changes
 network 10.10.20.0 mask 255.255.255.0
 network 192.168.2.0 route-map ATTACH_MED
 timers bgp 5 15
 neighbor 10.10.20.1 remote-as 64512
 neighbor 192.168.2.2 remote-as 64513
 neighbor 192.168.2.2 next-hop-self
!
!
!
ip access-list standard BGP_MED
 permit 192.168.2.0 0.0.0.255
!
!
route-map ATTACH_MED permit 10
 match ip address BGP_MED
 set metric 10
!
<\/pre>\n
\u305d\u308c\u305e\u308c\u306e\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u30c6\u30fc\u30d6\u30eb\u306e\u72b6\u614b\uff0e <\/p>\n
R1#show ip route bgp
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

Gateway of last resort is not set

      10.0.0.0\/8 is variably subnetted, 3 subnets, 2 masks
B        10.10.20.0\/24 [200\/0] via 192.168.1.3, 22:04:03
B     192.168.2.0\/24 [20\/0] via 10.10.10.2, 22:04:03
<\/pre>\n
R2#show ip route bgp
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

Gateway of last resort is not set

      10.0.0.0\/8 is variably subnetted, 3 subnets, 2 masks
B        10.10.10.0\/24 [200\/0] via 192.168.1.2, 22:04:10
B     192.168.2.0\/24 [200\/0] via 192.168.1.2, 22:04:01
<\/pre>\n
R3#show ip route  bgp
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

Gateway of last resort is not set

      10.0.0.0\/8 is variably subnetted, 3 subnets, 2 masks
B        10.10.20.0\/24 [200\/0] via 192.168.2.3, 22:04:28
B     192.168.1.0\/24 [20\/0] via 10.10.10.1, 22:04:29
<\/pre>\n
R4#show ip route bgp
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

Gateway of last resort is not set

      10.0.0.0\/8 is variably subnetted, 3 subnets, 2 masks
B        10.10.10.0\/24 [200\/0] via 192.168.2.2, 22:05:38
B     192.168.1.0\/24 [200\/0] via 192.168.2.2, 22:05:35
<\/pre>\n
PC1\uff5ePC2\u9593\u3067Ping\u3092\u6253\u3061\u7d9a\u3051\uff0cR1\u3068R3\u306e\u30ea\u30f3\u30af\u3092\u30c0\u30a6\u30f3\u3055\u305b\u308b\uff0e<\/p>\n
R1#show ip bgp neighbors 10.10.10.2 | inc hold time
  Last read 00:00:02, last write 00:00:02, hold time is 15, keepalive interval is 5 seconds
  Configured hold time is 15, keepalive interval is 5 seconds
<\/pre>\n
\u306a\u304a\uff0cBGP\u306e\u72b6\u614b\u306f\u8a2d\u5b9a\u901a\u308a\u306b15\u79d2keepalive\u304c\u7121\u304b\u3063\u305f\u3089\u30cd\u30a4\u30d0\u30fc\u3092\u30c0\u30a6\u30f3\u3068\u3059\u308b\u8a2d\u5b9a\u3068\u306a\u3063\u3066\u3044\u308b\uff0e 
\u7d50\u679c\u3092\u898b\u308b\u3068 <\/p>\n
PC1> ping 192.168.2.10 -t -w 10 -i 1000

84 bytes from 192.168.2.10 icmp_seq=1 ttl=62 time=1.646 ms
84 bytes from 192.168.2.10 icmp_seq=2 ttl=62 time=0.435 ms
84 bytes from 192.168.2.10 icmp_seq=3 ttl=62 time=0.541 ms
192.168.2.10 icmp_seq=4 timeout
192.168.2.10 icmp_seq=5 timeout
192.168.2.10 icmp_seq=6 timeout
192.168.2.10 icmp_seq=7 timeout
192.168.2.10 icmp_seq=8 timeout
192.168.2.10 icmp_seq=9 timeout
192.168.2.10 icmp_seq=10 timeout
192.168.2.10 icmp_seq=11 timeout
192.168.2.10 icmp_seq=12 timeout
192.168.2.10 icmp_seq=13 timeout
192.168.2.10 icmp_seq=14 timeout
192.168.2.10 icmp_seq=15 timeout
84 bytes from 192.168.2.10 icmp_seq=16 ttl=61 time=0.447 ms
84 bytes from 192.168.2.10 icmp_seq=17 ttl=61 time=0.490 ms
84 bytes from 192.168.2.10 icmp_seq=18 ttl=61 time=0.510 ms
84 bytes from 192.168.2.10 icmp_seq=19 ttl=61 time=0.460 ms
^C
<\/pre>\n
\u304a\u3088\u305d15\u79d2\u7a0b\u5ea6\u3067\u758e\u901a\u304c\u56de\u5fa9\u3057\u3066\u3044\u308b\uff0eR1\u3067Debug\u3092\u6709\u52b9\u306b\u3057\u3066\u72b6\u614b\u3092\u78ba\u8a8d\u3059\u308b\u3068\uff0c <\/p>\n
R1#show ip bgp neighbors 10.10.10.2 | inc hold time
  Last read 00:00:14, last write 00:00:03, hold time is 15, keepalive interval is 5 seconds
  Configured hold time is 15, keepalive interval is 5 seconds
R1#show ip bgp neighbors 10.10.10.2 | inc hold time
  Configured hold time is 15, keepalive interval is 5 seconds
R1#show ip bgp neighbors 10.10.10.2 | inc hold time
*Mar 29 07:18:51.950: %BGP-3-NOTIFICATION: sent to neighbor 10.10.10.2 4\/0 (hold time expired) 0 bytes
*Mar 29 07:18:51.950: %BGP-5-NBR_RESET: Neighbor 10.10.10.2 reset (BGP Notification sent)
*Mar 29 07:18:51.950: BGP(0): no valid path for 192.168.2.0\/24
*Mar 29 07:18:51.950: %BGP-5-ADJCHANGE: neighbor 10.10.10.2 Down BGP Notification sent
*Mar 29 07:18:51.950: %BGP_SESSION-5-ADJCHANGE: neighbor 10.10.10.2 IPv4 Unicast topology base removed from session  BGP Notification sent
R1#show ip bgp neighbors 10.10.10.2 | inc hold time
  Configured hold time is 15, keepalive interval is 5 seconds
R1#
<\/pre>\n
\u3068\u3061\u3083\u3093\u306815\u79d2\u3067\u5207\u308a\u66ff\u308f\u308b\u52d5\u304d\u3092\u3057\u3066\u3044\u308b\uff0e <\/p>\n
\u3053\u3053\u3067BFD\u306e\u5b9a\u7fa9\u3092\u5165\u308c\u308b\uff0e
Cisco IOS\u3067\u306f\u30a4\u30f3\u30bf\u30d5\u30a7\u30fc\u30b9\u5358\u4f4d\u3084\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u3092\u4f5c\u6210\u3057\u3066\u305d\u308c\u3092\u5143\u306b\u753b\u4e00\u7684\u306a\u5b9a\u7fa9\u3092\u7ba1\u7406\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u308b\uff0e\u4eca\u56de\u306f\u30b7\u30f3\u30d7\u30eb\u306b\u30a4\u30f3\u30bf\u30d5\u30a7\u30fc\u30b9\u4e8b\u306b\u8a2d\u5b9a\u3059\u308b\uff0e
BFD\u306e\u52d5\u4f5c\u306b\u95a2\u3059\u308b\u4e3b\u306a\u8a2d\u5b9a\u30d1\u30e9\u30e1\u30fc\u30bf\u306f\u4ee5\u4e0b\u306e\u901a\u308a\uff0e<\/p>\n
 interval min-tx milliseconds min-rx milliseconds multiplier multiplier-value
<\/pre>\n
\u300cmin-tx\u300d\u3067\u9001\u4fe1\u9593\u9694\uff0c\u300cmin-rx\u300d\u3067\u53d7\u4fe1\u9593\u9694\uff0c\u300cmultiplier\u300d\u3067\u30c0\u30a6\u30f3\u691c\u77e5\u3068\u3059\u308bkeepalive\u30d1\u30b1\u30c3\u30c8\u306e\u6570\u3092\u6307\u5b9a\u3059\u308b\uff0e<\/p>\n
R1\u629c\u7c8b <\/p>\n
interface Ethernet0\/0
 ip address 10.10.10.1 255.255.255.0
 bfd interval 100 min_rx 100 multiplier 3   #\u8ffd\u52a0
!
interface Ethernet0\/1
 ip address 192.168.1.2 255.255.255.0
 standby 1 ip 192.168.1.1
 standby 1 preempt delay minimum 5
 bfd interval 100 min_rx 100 multiplier 3   #\u8ffd\u52a0
!
!
!
router bgp 64512
 bgp log-neighbor-changes
 network 10.10.10.0 mask 255.255.255.0
 network 192.168.1.0
 timers bgp 5 15
 neighbor 10.10.10.2 remote-as 64513
 neighbor 10.10.10.2 fall-over bfd          #\u8ffd\u52a0
 neighbor 192.168.1.3 remote-as 64512
 neighbor 192.168.1.3 fall-over bfd         #\u8ffd\u52a0
 neighbor 192.168.1.3 next-hop-self
!
<\/pre>\n
R2\u629c\u7c8b <\/p>\n
interface Ethernet0\/0
 ip address 10.10.20.1 255.255.255.0
 bfd interval 100 min_rx 100 multiplier 3   #\u8ffd\u52a0
!
interface Ethernet0\/1
 ip address 192.168.1.3 255.255.255.0
 standby 1 ip 192.168.1.1
 standby 1 priority 10
 standby 1 preempt delay minimum 5
 bfd interval 100 min_rx 100 multiplier 3   #\u8ffd\u52a0
!
!
!
router bgp 64512
 bgp log-neighbor-changes
 network 10.10.20.0 mask 255.255.255.0
 network 192.168.1.0
 timers bgp 5 15
 neighbor 10.10.20.2 remote-as 64513
 neighbor 10.10.20.2 fall-over bfd          #\u8ffd\u52a0
 neighbor 10.10.20.2 route-map ATTACH_MED out
 neighbor 192.168.1.2 remote-as 64512
 neighbor 192.168.1.2 fall-over bfd         #\u8ffd\u52a0
!
<\/pre>\n
R3\u629c\u7c8b <\/p>\n
interface Ethernet0\/0
 ip address 10.10.10.2 255.255.255.0
 bfd interval 100 min_rx 100 multiplier 3   #\u8ffd\u52a0
!
interface Ethernet0\/1
 ip address 192.168.2.2 255.255.255.0
 standby 1 ip 192.168.2.1
 standby 1 preempt delay minimum 3
 bfd interval 100 min_rx 100 multiplier 3   #\u8ffd\u52a0
!
!
!
router bgp 64513
 bgp log-neighbor-changes
 network 10.10.10.0 mask 255.255.255.0
 network 192.168.2.0
 timers bgp 5 15
 neighbor 10.10.10.1 remote-as 64512
 neighbor 10.10.10.1 fall-over bfd          #\u8ffd\u52a0
 neighbor 192.168.2.3 remote-as 64513
 neighbor 192.168.2.3 fall-over bfd         #\u8ffd\u52a0
 neighbor 192.168.2.3 next-hop-self
<\/pre>\n
R4\u629c\u7c8b <\/p>\n
interface Ethernet0\/0
 ip address 10.10.20.2 255.255.255.0
 bfd interval 100 min_rx 100 multiplier 3   #\u8ffd\u52a0
!
interface Ethernet0\/1
 ip address 192.168.2.3 255.255.255.0
 standby 1 ip 192.168.2.1
 standby 1 priority 10
 standby 1 preempt delay minimum 30
 bfd interval 100 min_rx 100 multiplier 3   #\u8ffd\u52a0
!
!
!
router bgp 64513
 bgp log-neighbor-changes
 network 10.10.20.0 mask 255.255.255.0
 timers bgp 5 15
 neighbor 10.10.20.1 remote-as 64512
 neighbor 10.10.20.1 fall-over bfd          #\u8ffd\u52a0
 neighbor 10.10.20.1 route-map ATTACH_MED out
 neighbor 192.168.2.2 remote-as 64513
 neighbor 192.168.2.2 fall-over bfd         #\u8ffd\u52a0
 neighbor 192.168.2.2 next-hop-self
<\/pre>\n
\u30b9\u30c6\u30fc\u30bf\u30b9\u78ba\u8a8d\uff0e\uff08R1\uff5eR3\u9593\uff09 <\/p>\n
R1#show bfd neighbors details

IPv4 Sessions
NeighAddr                              LD\/RD         RH\/RS     State     Int
10.10.10.2                              4\/4          Up        Up        Et0\/0
Session state is UP and using echo function with 100 ms interval.
Session Host: Software
OurAddr: 10.10.10.1
Handle: 2
Local Diag: 0, Demand mode: 0, Poll bit: 0
MinTxInt: 1000000, MinRxInt: 1000000, Multiplier: 3
Received MinRxInt: 1000000, Received Multiplier: 3
Holddown (hits): 0(0), Hello (hits): 1000(612)
Rx Count: 617, Rx Interval (ms) min\/max\/avg: 1\/1008\/879 last: 681 ms ago
Tx Count: 613, Tx Interval (ms) min\/max\/avg: 755\/1005\/884 last: 681 ms ago
Elapsed time watermarks: 0 0 (last: 0)
Registered protocols: BGP
Uptime: 00:09:02
Last packet: Version: 1                  - Diagnostic: 0
             State bit: Up               - Demand bit: 0
             Poll bit: 0                 - Final bit: 0
             C bit: 0
             Multiplier: 3               - Length: 24
             My Discr.: 4                - Your Discr.: 4
             Min tx interval: 1000000    - Min rx interval: 1000000
             Min Echo interval: 100000

<\/pre>\n
\u5148\u307b\u3069\u3068\u540c\u69d8\u306bR1\uff5eR3\u9593\u306e\u30a4\u30f3\u30bf\u30d5\u30a7\u30fc\u30b9\u3092\u30c0\u30a6\u30f3\u3055\u305b\u308b\uff0e <\/p>\n
PC1> ping 192.168.2.10 -t -w 10 -i 1000

84 bytes from 192.168.2.10 icmp_seq=1 ttl=62 time=0.480 ms
84 bytes from 192.168.2.10 icmp_seq=2 ttl=62 time=0.391 ms
84 bytes from 192.168.2.10 icmp_seq=3 ttl=62 time=0.478 ms
84 bytes from 192.168.2.10 icmp_seq=4 ttl=62 time=0.501 ms
84 bytes from 192.168.2.10 icmp_seq=5 ttl=62 time=0.414 ms
84 bytes from 192.168.2.10 icmp_seq=6 ttl=62 time=0.366 ms
84 bytes from 192.168.2.10 icmp_seq=7 ttl=62 time=0.412 ms
84 bytes from 192.168.2.10 icmp_seq=8 ttl=62 time=0.527 ms
84 bytes from 192.168.2.10 icmp_seq=9 ttl=62 time=0.439 ms
84 bytes from 192.168.2.10 icmp_seq=10 ttl=62 time=0.380 ms
84 bytes from 192.168.2.10 icmp_seq=11 ttl=62 time=0.499 ms
84 bytes from 192.168.2.10 icmp_seq=12 ttl=62 time=0.442 ms
84 bytes from 192.168.2.10 icmp_seq=13 ttl=62 time=0.420 ms
84 bytes from 192.168.2.10 icmp_seq=14 ttl=62 time=0.506 ms
84 bytes from 192.168.2.10 icmp_seq=15 ttl=62 time=0.495 ms
84 bytes from 192.168.2.10 icmp_seq=16 ttl=62 time=0.424 ms
84 bytes from 192.168.2.10 icmp_seq=17 ttl=62 time=0.445 ms
84 bytes from 192.168.2.10 icmp_seq=18 ttl=61 time=0.423 ms
84 bytes from 192.168.2.10 icmp_seq=19 ttl=61 time=0.653 ms
84 bytes from 192.168.2.10 icmp_seq=20 ttl=61 time=0.518 ms
84 bytes from 192.168.2.10 icmp_seq=21 ttl=61 time=0.677 ms
84 bytes from 192.168.2.10 icmp_seq=22 ttl=61 time=0.714 ms
84 bytes from 192.168.2.10 icmp_seq=23 ttl=61 time=0.690 ms
84 bytes from 192.168.2.10 icmp_seq=24 ttl=61 time=0.832 ms
84 bytes from 192.168.2.10 icmp_seq=25 ttl=61 time=0.741 ms
84 bytes from 192.168.2.10 icmp_seq=26 ttl=61 time=0.743 ms
84 bytes from 192.168.2.10 icmp_seq=27 ttl=61 time=0.693 ms
84 bytes from 192.168.2.10 icmp_seq=28 ttl=61 time=0.673 ms
84 bytes from 192.168.2.10 icmp_seq=29 ttl=61 time=0.630 ms
^C
<\/pre>\n
R1\u306e\u30c7\u30d0\u30c3\u30b0\u30ed\u30b0 <\/p>\n
R1#
*Mar 29 07:36:15.391: %BGP-5-NBR_RESET: Neighbor 10.10.10.2 reset (BFD adjacency down)
*Mar 29 07:36:15.395: BGP(0): no valid path for 192.168.2.0\/24
*Mar 29 07:36:15.395: %BGP-5-ADJCHANGE: neighbor 10.10.10.2 Down BFD adjacency down
*Mar 29 07:36:15.395: %BGP_SESSION-5-ADJCHANGE: neighbor 10.10.10.2 IPv4 Unicast topology base removed from session  BFD adjacency down
R1#
*Mar 29 07:36:15.400: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 192.168.2.0\/24
*Mar 29 07:36:15.400: BGP(0): (base) 192.168.1.3 send unreachable (format) 192.168.2.0\/24
*Mar 29 07:36:15.400: BGP(0): 192.168.1.3 rcvd UPDATE w\/ attr: nexthop 192.168.1.3, origin i, localpref 100, metric 10, merged path 64513, AS_PATH
*Mar 29 07:36:15.400: BGP(0): 192.168.1.3 rcvd 192.168.2.0\/24
*Mar 29 07:36:15.400: BGP(0): Revise route installing 1 of 1 routes for 192.168.2.0\/24 -> 192.168.1.3(global) to main IP table<\/pre>\n
msec\u3067\u5207\u308a\u66ff\u308f\u308b\u306e\u3067\uff0c\u30ed\u30b0\u304b\u3089\u306f\u5206\u304b\u3089\u306a\u3044\u304c\uff0c\u30a4\u30f3\u30bf\u30d5\u30a7\u30fc\u30b9\u304c\u843d\u3061\u305f\u77ac\u9593\u306b\u3053\u306e\u30ed\u30b0\u304c\u6d41\u308c\u898b\u305f\u76ee\u4e0a\u3082Ping\u306e\u30d1\u30b1\u30ed\u30b9\u306f\u767a\u751f\u3057\u306a\u304b\u3063\u305f\uff0e<\/br>\u3061\u306a\u307f\u306b\u30a4\u30f3\u30bf\u30d5\u30a7\u30fc\u30b9\u306e\u5207\u308a\u623b\u308a\u306b\u304a\u3044\u3066\u306fBFD\u306f\u52b9\u679c\u304c\u306a\u304f\uff0cBGP\u306e\u30bf\u30a4\u30de\u30fc\u306b\u5f93\u3063\u3066\u7d4c\u8def\u304c\u623b\u308b\uff0e\u3053\u308c\u306fBFD\u306f\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u30d7\u30ed\u30c8\u30b3\u30eb\u3042\u308a\u304d\u3067\u52d5\u4f5c\u3059\u308b\u88dc\u52a9\u30d7\u30ed\u30c8\u30b3\u30eb\u3067\u3042\u308b\u305f\u3081\u3060\u3068\u601d\u308f\u308c\u308b\uff0e<\/br>BGP\u306e\u30cd\u30a4\u30d0\u30fc\u304c\u5f35\u3089\u308c\u308b\u307e\u3067\u306fBFD\u3082\u30a2\u30c3\u30d7\u306b\u306a\u3089\u306a\u3044\uff0e <\/p>\n

R1#show bfd summary

                    Session          Up          Down

Total                     1           1             0
R1#
*Mar 29 08:08:01.616: %BGP-5-ADJCHANGE: neighbor 10.10.10.2 Up
*Mar 29 08:08:01.617: BGP(0): (base) 10.10.10.2 send UPDATE (format) 192.168.2.0\/24, next 10.10.10.1, metric 10, path 64513
*Mar 29 08:08:01.617: BGP(0): (base) 10.10.10.2 send UPDATE (format) 10.10.20.0\/24, next 10.10.10.1, metric 0, path Local
*Mar 29 08:08:01.617: BGP(0): (base) 10.10.10.2 send UPDATE (format) 192.168.1.0\/24, next 10.10.10.1, metric 0, path Local
*Mar 29 08:08:01.618: BGP(0): 10.10.10.2 rcv UPDATE w\/ attr: nexthop 10.10.10.2, origin i, originator 0.0.0.0, merged path 64513 64512, AS_PATH , community , extended community , SSA attribute
*Mar 29 08:08:01.618: BGPSSA ssacount is 0
*Mar 29 08:08:01.618: BGP(0): 10.10.10.2 rcv UPDATE about 192.168.1.0\/24 -- DENIED due to: AS-PATH contains our own AS;
*Mar 29 08:08:01.618: BGP(0): 10.10.10.2 rcvd UPDATE w\/ attr: nexthop 10.10.10.2, origin i, merged path 64513, AS_PATH
*Mar 29 08:08:01.618: BGP(0): 10.10.10.2 rcvd 10.10.20.0\/24
*Mar 29 08:08:01.618: BGP(0): 10.10.10.2 rcvd UPDATE w\/ attr: nexthop 10.10.10.2, origin i, metric 0, merged path 64513, AS_PATH
*Mar 29 08:08:01.618: BGP(0): 10.10.10.2 rcvd 10.10.10.0\/24
*Mar 29 08:08:01.618: BGP(0): 10.10.10.2 rcvd 192.168.2.0\/24
*Mar 29 08:08:01.618: BGP(0): Revise route installing 1 of 1 routes for 192.168.2.0\/24 -> 10.10.10.2(global) to main IP table
R1#
*Mar 29 08:08:01.618: BGP(0): 192.168.1.3 NEXT_HOP is set to self for net 192.168.2.0\/24,
*Mar 29 08:08:01.618: BGP(0): (base) 192.168.1.3 send UPDATE (format) 192.168.2.0\/24, next 192.168.1.2, metric 0, path 64513
*Mar 29 08:08:01.623: BGP(0): 192.168.1.3 rcv UPDATE about 192.168.2.0\/24 -- withdrawn
R1#
R1#show bfd summary

                    Session          Up          Down

Total                     2           2             0
R1#
<\/pre>\n","protected":false},"excerpt":{"rendered":"
\u901a\u5e38\uff0c\u30c0\u30a4\u30ca\u30df\u30c3\u30af\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u3092\u5229\u7528\u3057\u3066\u7d4c\u8def\u306e\u5207\u308a\u66ff\u308f\u308a\u3092\u5236\u5fa1\u3059\u308b\u5834\u5408\uff0c\u30bf\u30a4\u30de\u30fc\u306e\u5024\u3092\u8abf\u6574\u3057\u3066\u884c\u3044\u307e\u3059\u304c\uff0c\u305b\u3044\u305c\u3044\u79d2\u5358\u4f4d\u3067\u306e\u5207\u308a\u66ff\u308f\u308a\u304c\u9650\u754c\u3067\u3059\uff0e BFD\uff08Bidirectional Forwarding Detecti\u2026 \u7d9a\u304d\u3092\u8aad\u3080 »<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":206,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25,23,11,24,15,22],"tags":[],"class_list":["post-484","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bfd","category-bgp","category-cisco","category-eve-ng","category-network","category-routing"],"_links":{"self":[{"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/posts\/484","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=484"}],"version-history":[{"count":1,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/posts\/484\/revisions"}],"predecessor-version":[{"id":621,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/posts\/484\/revisions\/621"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/media\/206"}],"wp:attachment":[{"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=484"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=484"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=484"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}