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Neighbors list
| Description | Analyze neighors list outputthe neighbors. The routers are connected by through the 172.16.0.0/29 network, which is a broadcast segment (using the MINT protocol), so: - CPE3 is selected elected as DR, its router-id is being the highest.
- CPE2 is selected elected as BDR, its router-id less than CPE3, but more than BS1being the highest after CPE3.
- BS1 is DROther.
- The routers have established a Full relationshiprelations.
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| BS1 | | Code Block |
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| OSPF> show neighbor
Neighbor ID Pri State Dead Time Address Interface RXmtL RqstL DBsmL
192.168.0.2 1 Full/Backup 00:00:38 172.16.0.2 rf5.0:172.16.0.1 0 0 0
192.168.0.3 1 Full/DR 00:00:38 172.16.0.3 rf5.0:172.16.0.1 0 0 0 |
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| CPE2 | | Code Block |
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| OSPF> show neighbor
Neighbor ID Pri State Dead Time Address Interface RXmtL RqstL DBsmL
192.168.0.1 1 Full/DROther 00:00:33 172.16.0.1 rf5.0:172.16.0.2 0 0 0
192.168.0.3 1 Full/DR 00:00:35 172.16.0.3 rf5.0:172.16.0.2 0 0 0 |
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| CPE3 | | Code Block |
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| OSPF> show neighbor
Neighbor ID Pri State Dead Time Address Interface RXmtL RqstL DBsmL
192.168.0.1 1 Full/DROther 00:00:31 172.16.0.1 rf5.0:172.16.0.3 0 0 0
192.168.0.2 1 Full/Backup 00:00:37 172.16.0.2 rf5.0:172.16.0.3 0 0 0 |
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LSDB content
| Description | Analyze the LSDB. Since the scheme contains one area, the LSDB output on all the routers will be identical: - LSA type 1 (Router Link States): LSDB contains three LSA LSAs type 1, one from each of the area routers. Note , that each LSA can contain a lot of information. For example, the LSA type 1 generated by CPE2 contains information about the neighbors, about the 172.16.0.0/29 , and 10.10.20.0/24 networks and its own identifier.
- LSA type 2 (Net Link States): CPE3 router as DR generates has generated one LSA type 2.
- LSA type 5 (AS External Link States): by default, one LSA type 5 is generated for each external route, therefore the LSDB contains three LSA LSAs type 5 about routes to , one for each external networks: the routes to the networks 192.168.5.0/28 and 192.168.6.0/28 were generated during the redistribution of the CPE3's static routes , and the route to network 10.10 .10.0 / 24 is generated by BS1 during the redistribution of as a directly connected network.
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| BS1, CPE2, CPE3 | | Code Block |
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| OSPF> show database
OSPF Router with ID (192.168.0.1)(192.168.0.1)
Router Link States (Area 0.0.0.0)
Link ID ADV Router Age Seq# LS-Age Link count
192.168.0.1 192.168.0.1 202 0x80000008 7442 2
192.168.0.2 192.168.0.2 201 0x80000008 7405 3
192.168.0.3 192.168.0.3 204 0x8000000a 7407 3
Net Link States (Area 0.0.0.0)
Link ID ADV Router Age Seq# LS-Age Routers
172.16.0.3/29 192.168.0.3 204 0x80000006 7407 3
AS External Link States
Link ID ADV Router Age Seq# LS-Age Route
10.10.10.0 192.168.0.1 122 0x80000007 7442 E2 10.10.10.0/24 [0x0]
192.168.5.0 192.168.0.3 169 0x80000007 7407 E2 192.168.5.0/28 [0x0]
192.168.6.0 192.168.0.3 299 0x80000007 7407 E2 192.168.6.0/28 [0x0] |
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| Description | The routing tables of the wireless devices, contains entries that each device has information about contain entries for each subnet shown in the scheme. This means that the devices have successfully exchanged the routing information and added it to the FIB. Note , that the loopback interfaces' addresses do not depend on the links link state, therefore they can be used to manage the devices in redundant networks. |
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| BS1 | | Code Block |
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| BS_1#1> netstat -r
Routing tables
Destination Gateway Flags Refs Use Interface
10.10.10.0/24 link#2 UC 0 0 eth0
10.10.20.0/24 172.16.0.2 UG3 0 0 rf5.0
10.10.30.0/24 172.16.0.3 UG3 0 0 rf5.0
127.0.0.1 127.0.0.1 UH 3 141 lo0
172.16.0.0/29 link#3 UC 0 0 rf5.0
192.168.0.1 192.168.0.1 UH 0 0 lo0
192.168.0.2 172.16.0.2 UGH3 0 0 rf5.0
192.168.0.3 172.16.0.3 UGH3 0 0 rf5.0
192.168.5.0/28 172.16.0.3 UG3 0 0 rf5.0
192.168.6.0/28 172.16.0.3 UG3 0 0 rf5.0
224.0.0.0/8 127.0.0.1 UGS 1 1561 lo0 |
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| CPE2 | | Code Block |
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| AS_2#2> netstat -r
Routing tables
Destination Gateway Flags Refs Use Interface
10.10.10.0/24 172.16.0.1 UG3 0 0 rf5.0
10.10.20.0/24 link#2 UC 0 0 eth0
10.10.30.0/24 172.16.0.3 UG3 0 0 rf5.0
127.0.0.1 127.0.0.1 UH 3 50 lo0
172.16.0.0/29 link#3 UC 0 0 rf5.0
192.168.0.1 172.16.0.1 UGH3 0 0 rf5.0
192.168.0.2 192.168.0.2 UH 0 0 lo0
192.168.0.3 172.16.0.3 UGH3 0 0 rf5.0
192.168.5.0/28 172.16.0.3 UG3 0 0 rf5.0
192.168.6.0/28 172.16.0.3 UG3 0 0 rf5.0
224.0.0.0/8 127.0.0.1 UGS 1 2037 lo0 |
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| CPE3 | | Code Block |
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| AS_3#1> netstat -r
Routing tables
Destination Gateway Flags Refs Use Interface
10.10.10.0/24 172.16.0.1 UG3 0 0 rf5.0
10.10.20.0/24 172.16.0.2 UG3 0 0 rf5.0
10.10.30.0/24 link#2 UC 0 0 eth0
127.0.0.1 127.0.0.1 UH 3 155 lo0
172.16.0.0/29 link#3 UC 0 0 rf5.0
192.168.0.1 172.16.0.1 UGH3 0 0 rf5.0
192.168.0.2 172.16.0.2 UGH3 0 0 rf5.0
192.168.0.3 192.168.0.3 UH 0 0 lo0
192.168.5.0/28 10.10.30.1 UGS 0 0 eth0
192.168.6.0/28 10.10.30.1 UGS 0 0 eth0
224.0.0.0/8 127.0.0.1 UGS 1 1745 lo0 |
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Network scheme with several OSPF areas
Let's look at the example of a network scheme with several OSPF areas (Figure 3):
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