Kinh chào các anh chị và các bạn.
Mình đang gặp một thắc mắc về trao đổi dữ liệu khi các Route r hội tụ trong O SPF protocol
Khi các route r hội tụ thì chỉ trao đổi dữ liệu giữa DR, BDR và DRother.
Các DRother không hề trao đổi dữ liệu trực tiếp với nhau:
Như tài liệu của CCNA ICND2 trang 353-354 có đoạn như sau:
-------------------------
With the DR concept, as shown on the right side of Figure 9-3, that same LAN would require routing updates only between the DR and the nine other routers, significantly reducing the flooding of OSPF information across the LAN
------
Trong CCNA của Tood Lammle trang 465.
"The BDR is elected as a backup router in case the DR goes down. The idea behind this is
that routers have a central point of contact for information exchange. Instead of each router exchanging updates with every other router on the segment, every router exchanges informa-
tion with the DR and BDR. The DR and BDR then relay the information to everybody else.
-----------------------
Ấy vậy mà mình thực hành trên GNS3 nó lại khác. Kết quả là các DRother không những trao đổi dữ liệu DR, BDR mà còn trao đổi với những DRother khác.
Làm ơn xem đoạn script mình chép trong lúc gỡ rối và hình điính kèm.
Ai biết mình sai ở chỗ nào, hay là phần mềm lỗi làm ơn chỉ giúp.
Mình đã kiểm tra tất cả các trạng thái từ Neibor, adjacent, Routing.
Trương hợp này 172.16.0.3 là FULL/DR 172.16.0.1 là FULL/BDR và 172.16.0.2 là DROTHER và R0 với IP là 172.16.0.4 cũng là DROTHER.
Nếu đúng theo lý thuyết thì chỉ 172.16.0.3 là FULL/DR 172.16.0.1 là FULL/BDR và 172.16.0.2 và R0 với IP là 172.16.0.4 trao đổi dữ liệu với nhau thôi. Thế nhưng trường hợp này tại sao R0 với IP là 172.16.0.4 trao đổi dữ liệu với 172.16.0.2 như trong debug của R0 chỉ ra như vậy. Tại sao mâu thuẩn vậy nhỉ. Ai biết làm ơn chỉ giúp.
R0#sh ip ospf nei
Neighbor ID Pri State Dead Time Address Interface
172.16.1.1 1 FULL/BDR 00:00:31 172.16.0.1 Ethernet0/0
172.16.0.2 1 2WAY/DROTHER 00:00:35 172.16.0.2 Ethernet0/0
172.16.0.3 1 FULL/DR 00:00:39 172.16.0.3 Ethernet0/0
R0#
================================================== =======
R0#sh ip ospf data
OSPF Router with ID (172.16.0.4) (Process ID 40)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
172.16.0.2 172.16.0.2 342 0x80000002 0xF339 1
172.16.0.3 172.16.0.3 341 0x80000002 0xF138 1
172.16.0.4 172.16.0.4 333 0x80000003 0xED38 1
172.16.1.1 172.16.1.1 119 0x80000004 0xD6BE 2
172.16.1.2 172.16.1.2 119 0x80000002 0xE347 1
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
172.16.0.3 172.16.0.3 332 0x80000003 0x7544
172.16.1.1 172.16.1.1 119 0x80000001 0xF44C
R0#
=================================
R0#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i - IS-IS, 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
Gateway of last resort is not set
172.16.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.16.0.0/29 is directly connected, Ethernet0/0
O 172.16.1.0/30 [110/20] via 172.16.0.1, 00:02:05, Ethernet0/0
R0#
=====================================
R0#ping 172.16.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 124/149/192 ms
R0#
==========================
R0#debu ip ospf packet
OSPF packet debugging is on
R0#
00:06:52: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.3
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:06:53: OSPF: rcv. v:2 t:1 l:56 rid:172.16.1.1
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:06:57: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.2
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:02: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.3
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:03: OSPF: rcv. v:2 t:1 l:56 rid:172.16.1.1
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:07: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.2
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:12: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.3
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:13: OSPF: rcv. v:2 t:1 l:56 rid:172.16.1.1
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:17: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.2
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:22: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.3
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:23: OSPF: rcv. v:2 t:1 l:56 rid:172.16.1.1
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:27: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.2
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
R0#undebu all
All possible debugging has been turned off
R0#
==================================
R0#debu ip ospf even
OSPF events debugging is on
R0#
00:08:57: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:08:57: OSPF: End of hello processing
00:09:02: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:02: OSPF: End of hello processing
00:09:03: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:03: OSPF: End of hello processing
00:09:07: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:09:07: OSPF: End of hello processing
00:09:12: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:12: OSPF: End of hello processing
00:09:13: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:13: OSPF: End of hello processing
00:09:17: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:09:17: OSPF: End of hello processing
00:09:22: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:22: OSPF: End of hello processing
00:09:23: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:23: OSPF: End of hello processing
00:09:27: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:09:27: OSPF: End of hello processing
00:09:32: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:32: OSPF: End of hello processing
00:09:33: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:33: OSPF: End of hello processing
00:09:37: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:09:37: OSPF: End of hello processing
00:09:42: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:42: OSPF: End of hello processing
00:09:43: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:43: OSPF: End of hello processing
00:09:47: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:09:47: OSPF: End of hello processing
00:09:52: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:52: OSPF: End of hello processing
R0#undeb all
All possible debugging has been turned off
R0#
00:09:53: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:53: OSPF: End of hello processing
Mình đang gặp một thắc mắc về trao đổi dữ liệu khi các Route r hội tụ trong O SPF protocol
Khi các route r hội tụ thì chỉ trao đổi dữ liệu giữa DR, BDR và DRother.
Các DRother không hề trao đổi dữ liệu trực tiếp với nhau:
Như tài liệu của CCNA ICND2 trang 353-354 có đoạn như sau:
-------------------------
With the DR concept, as shown on the right side of Figure 9-3, that same LAN would require routing updates only between the DR and the nine other routers, significantly reducing the flooding of OSPF information across the LAN
------
Trong CCNA của Tood Lammle trang 465.
"The BDR is elected as a backup router in case the DR goes down. The idea behind this is
that routers have a central point of contact for information exchange. Instead of each router exchanging updates with every other router on the segment, every router exchanges informa-
tion with the DR and BDR. The DR and BDR then relay the information to everybody else.
-----------------------
Ấy vậy mà mình thực hành trên GNS3 nó lại khác. Kết quả là các DRother không những trao đổi dữ liệu DR, BDR mà còn trao đổi với những DRother khác.
Làm ơn xem đoạn script mình chép trong lúc gỡ rối và hình điính kèm.
Ai biết mình sai ở chỗ nào, hay là phần mềm lỗi làm ơn chỉ giúp.
Mình đã kiểm tra tất cả các trạng thái từ Neibor, adjacent, Routing.
Trương hợp này 172.16.0.3 là FULL/DR 172.16.0.1 là FULL/BDR và 172.16.0.2 là DROTHER và R0 với IP là 172.16.0.4 cũng là DROTHER.
Nếu đúng theo lý thuyết thì chỉ 172.16.0.3 là FULL/DR 172.16.0.1 là FULL/BDR và 172.16.0.2 và R0 với IP là 172.16.0.4 trao đổi dữ liệu với nhau thôi. Thế nhưng trường hợp này tại sao R0 với IP là 172.16.0.4 trao đổi dữ liệu với 172.16.0.2 như trong debug của R0 chỉ ra như vậy. Tại sao mâu thuẩn vậy nhỉ. Ai biết làm ơn chỉ giúp.
R0#sh ip ospf nei
Neighbor ID Pri State Dead Time Address Interface
172.16.1.1 1 FULL/BDR 00:00:31 172.16.0.1 Ethernet0/0
172.16.0.2 1 2WAY/DROTHER 00:00:35 172.16.0.2 Ethernet0/0
172.16.0.3 1 FULL/DR 00:00:39 172.16.0.3 Ethernet0/0
R0#
================================================== =======
R0#sh ip ospf data
OSPF Router with ID (172.16.0.4) (Process ID 40)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
172.16.0.2 172.16.0.2 342 0x80000002 0xF339 1
172.16.0.3 172.16.0.3 341 0x80000002 0xF138 1
172.16.0.4 172.16.0.4 333 0x80000003 0xED38 1
172.16.1.1 172.16.1.1 119 0x80000004 0xD6BE 2
172.16.1.2 172.16.1.2 119 0x80000002 0xE347 1
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
172.16.0.3 172.16.0.3 332 0x80000003 0x7544
172.16.1.1 172.16.1.1 119 0x80000001 0xF44C
R0#
=================================
R0#sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
i - IS-IS, 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
Gateway of last resort is not set
172.16.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.16.0.0/29 is directly connected, Ethernet0/0
O 172.16.1.0/30 [110/20] via 172.16.0.1, 00:02:05, Ethernet0/0
R0#
=====================================
R0#ping 172.16.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 124/149/192 ms
R0#
==========================
R0#debu ip ospf packet
OSPF packet debugging is on
R0#
00:06:52: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.3
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:06:53: OSPF: rcv. v:2 t:1 l:56 rid:172.16.1.1
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:06:57: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.2
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:02: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.3
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:03: OSPF: rcv. v:2 t:1 l:56 rid:172.16.1.1
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:07: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.2
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:12: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.3
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:13: OSPF: rcv. v:2 t:1 l:56 rid:172.16.1.1
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:17: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.2
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:22: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.3
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:23: OSPF: rcv. v:2 t:1 l:56 rid:172.16.1.1
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
00:07:27: OSPF: rcv. v:2 t:1 l:56 rid:172.16.0.2
aid:0.0.0.0 chk:F228 aut:0 auk: from Ethernet0/0
R0#undebu all
All possible debugging has been turned off
R0#
==================================
R0#debu ip ospf even
OSPF events debugging is on
R0#
00:08:57: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:08:57: OSPF: End of hello processing
00:09:02: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:02: OSPF: End of hello processing
00:09:03: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:03: OSPF: End of hello processing
00:09:07: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:09:07: OSPF: End of hello processing
00:09:12: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:12: OSPF: End of hello processing
00:09:13: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:13: OSPF: End of hello processing
00:09:17: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:09:17: OSPF: End of hello processing
00:09:22: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:22: OSPF: End of hello processing
00:09:23: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:23: OSPF: End of hello processing
00:09:27: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:09:27: OSPF: End of hello processing
00:09:32: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:32: OSPF: End of hello processing
00:09:33: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:33: OSPF: End of hello processing
00:09:37: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:09:37: OSPF: End of hello processing
00:09:42: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:42: OSPF: End of hello processing
00:09:43: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:43: OSPF: End of hello processing
00:09:47: OSPF: Rcv hello from 172.16.0.2 area 0 from Ethernet0/0 172.16.0.2
00:09:47: OSPF: End of hello processing
00:09:52: OSPF: Rcv hello from 172.16.0.3 area 0 from Ethernet0/0 172.16.0.3
00:09:52: OSPF: End of hello processing
R0#undeb all
All possible debugging has been turned off
R0#
00:09:53: OSPF: Rcv hello from 172.16.1.1 area 0 from Ethernet0/0 172.16.0.1
00:09:53: OSPF: End of hello processing
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