Page History

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Description

Perform a preliminary configuration of the wireless devices consisting of the following steps:

Configure the router IDIDs.
Remove the svi1 interface.
Assign IP addresses to network interfaces, according to the scheme.
Add static entries to the routing table.
Disable switching.
Establish the wireless links.

BS1

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Set the device ID
system prompt BS_1

Remove the svi1 interface
ifc svi1 destroy

Assign IP addresses
ifc eth0 10.10.10.1/24
ifc rf5.0 172.16.0.1/30
ifc rf5.0 172.16.3.1/30
ifc rf5.0 172.16.4.1/30
ifc lo0 192.168.0.1/32

Disable switching
switch stop

Establish the radio link
rf rf5.0 band 20
rf rf5.0 freq 5000

mint rf5.0 -name "BS_1"
mint rf5.0 -type master

CPE2

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Set the device ID
system prompt CPE_2

Remove the svi1 interface
ifc svi1 destroy

Assign IP addresses
ifc eth0 10.10.20.2/24
ifc rf5.0 172.16.0.2/30
ifc lo0 192.168.0.2/32

Disable switching
switch stop

Establish the radio link
mint rf5.0 -name "CPE_2"
mint rf5.0 -type slave
mint rf5.0 prof 1 -band 20 -freq 5000 -type slave

CPE3

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Set the device ID
system prompt CPE_3

Remove the svi1 interface
ifc svi1 destroy

Assign IP addresses
ifc eth0 10.10.30.3/24
ifc rf5.0 172.16.3.2/30
ifc lo0 192.168.0.3/32

Add static routes
route add 192.168.5.0/28 10.10.30.1
route add 192.168.6.0/28 10.10.30.1

Disable switching
switch stop

Establish the radio link
mint rf5.0 -name "CPE_3"
mint rf5.0 -type slave
mint rf5.0 prof 1 -band 20 -freq 5000 -type slave

CPE4

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Set the device ID
system prompt CPE_4

Remove the svi1 interface
ifc svi1 destroy

Assign IP addresses
ifc eth0 10.10.40.4/24
ifc rf5.0 172.16.4.2/30
ifc lo0 192.168.0.4/32

Disable switching
switch stop

Establish the radio link
mint rf5.0 -name "CPE_4"
mint rf5.0 -type slave
mint rf5.0 prof 1 -band 20 -freq 5000 -type slave

...

Description

Let's configure the OSPF protocol according to the scheme.

Step 1: start OSPF.

Step 2: configure the router IDs. The identifiers will be equal to the IP addresses assigned to the loopback interface.

Step 3: define the interfaces where OSPF should be started. All the interfaces are connected to the backbone area according to the scheme.

Step 4: define the area types: area 3 - NSSA, area 4 - Stub. Note that the area type must be configured on all the routers connected to that area, otherwise they will not establish neighboring relations.

Step 5: perform the redistribution of the directly connected networks on the BS1 router and pf of the static routes on the CPE3 router.

Step 6: configure passive interfaces.

BS1

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Start OSPF
ospf start

Set the router-id
ospf
config
router
router-id 192.168.0.1

Start OSPF on the interfaces
ospf
config
router
network 172.16.0.0/30 area 0.0.0.0
network 172.16.3.0/30 area 0.0.0.3
network 172.16.4.0/30 area 0.0.0.4
network 192.168.0.1/32 area 0.0.0.0

Set the area types
ospf
config
router
area 0.0.0.3 nssa
area 0.0.0.4 stub

Redistribute the connected routes
ospf
config
router
redistribute connected

CPE2

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Start OSPF
ospf start

Set the router-id
ospf
config
router
router-id 192.168.0.2

Start OSPF on the interfaces
ospf
config
router
network 10.10.20.0/24 area 0.0.0.0
network 172.16.0.0/30 area 0.0.0.0
network 192.168.0.2/32 area 0.0.0.0

CPE3

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Start OSPF
ospf start

Set the router-id
ospf
config
router
router-id 192.168.0.3

Start OSPF on the interfaces
ospf
config
router
network 10.10.30.0/24 area 0.0.0.3
network 172.16.3.0/30 area 0.0.0.3
network 192.168.0.3/32 area 0.0.0.3

Set the area types
ospf
config
router
area 0.0.0.3 nssa

Redistribute the static routes
ospf
config
router
redistribute kernel

Set the passive interfaces
passive-interface eth0

CPE4

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Start OSPF
ospf start

Set the router-id
ospf
config
router
router-id 192.168.0.4

Start OSPF on the interfaces
ospf
config
router
network 10.10.40.0/24 area 0.0.0.4
network 172.16.4.0/30 area 0.0.0.4
network 192.168.0.4/32 area 0.0.0.4

Set the area types
ospf
config
router
area 0.0.0.4 stub

Redistribute the static routes
ospf
config
router
redistribute kernel

...

Description

Let's analyze the LSDB. Unlike in the case of the scheme with one area, in this example the LSA set of LSAs for each area will be different.

Area 0:

LSA type 1 (Router Link States): The LSDB contains two LSAs type 1, from each area router.
LSA type 2 (Net Link States): CPE2 as DR, has generated one LSA type 2.
LSA type 3 (Summary Link States): the LSDB contains 6 LSAs type 3 about the networks in different areas.
LSA type 4 (ASBR-Summary Link States): CPE3 is ASBR and it is located in area 3, so it redistributes the static routes. BS1 generates an LSA type 4 for area 0 with information about the location of the ASBR (CPE3).
LSA type 5 (AS External Link States): By default, one LSA type 5 is generated for each external route, therefore the LSDB contains three LSAs type 5 containing the routes to the external networks: the routes to the networks 192.168.5.0/28 and 192.168.6.0/28 were generated during the redistribution of CPE3's static routes, while the route to network 10.10.10.0/24 is generated by BS1 during the redistribution as a directly connected network. Since area 3 is an NSSA, LSAs type 5 about the networks 192.168.5.0/28 and 192.168.6.0/28 for area 0 are generated by the BS1 to replace the LSA type 7 from CPE3.

Area 3:

LSA type 1 (Router Link States): The LSDB contains two LSAs type 1, from each area router.
LSA type 2 (Net Link States): CPE3 as DR generates one LSA type 2.
LSA type 3 (Summary Link States): the LSDB contains 7 LSAs type 3 about the networks in different areas, similar to area 0. The difference is in the LSA with a default route generated by BS1 for area 3.
LSA type 5 (AS External Link States): the CPE3 router generates 2 LSAs type 5 with information about the static routes (redistribution). The presence of these LSAs in the LSDB is formal, since CPE3 converts them to LSA type 7 and forwards them to the neighbors.
LSA type 7 (NSSA-external Link States): the external routes are transmitted using LSA type 7 in NSSA type areas, so the LSDB includes three LSAs of this type.

Area 4:

LSA type 1 (Router Link States): The LSDB contains two LSAs type 1, one from each area router.
LSA type 2 (Net Link States): CPE4 as DR generates one LSA type 2.
LSA type 3 (Summary Link States): the LSDB contains 7 LSAs type 3 about the networks in different areas and one LSA type 3, with a default route. Stub areas do not support the distribution of the routes to towards the external networks, which are replaced by the default route distribution in LSA type 3.

Note: routers CPE2, CPE3 and CPE4 use only LSAs generated for areas 0, 3, and 4. BS1's LSDB includes LSAs for all areas, since BS1 is ABR and it is set at the border of all three areas.

BS1

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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      235 0x80000003    246 2
192.168.0.2     192.168.0.2      232 0x80000005    243 3

                Net Link States (Area 0.0.0.0)

Link ID            ADV Router      Age  Seq#       LS-Age Routers
172.16.0.2/30      192.168.0.2      244 0x80000001    243 2

                Summary Link States (Area 0.0.0.0)

Link ID         ADV Router      Age  Seq#       LS-Age Route
10.10.30.0      192.168.0.1      237 0x80000001    237 10.10.30.0/24
10.10.40.0      192.168.0.1      237 0x80000001    237 10.10.40.0/24
172.16.3.0      192.168.0.1      245 0x80000001    245 172.16.3.0/30
172.16.4.0      192.168.0.1      245 0x80000001    245 172.16.4.0/30
192.168.0.3     192.168.0.1      237 0x80000001    237 192.168.0.3/32
192.168.0.4     192.168.0.1      237 0x80000001    237 192.168.0.4/32

                ASBR-Summary Link States (Area 0.0.0.0)

Link ID         ADV Router      Age  Seq#       LS-Age
192.168.0.3     192.168.0.1      237 0x80000001    237

                Router Link States (Area 0.0.0.3 [NSSA])

Link ID         ADV Router      Age  Seq#       LS-Age Link count
192.168.0.1     192.168.0.1      236 0x80000003    246 1
192.168.0.3     192.168.0.3      224 0x80000005    243 3

                Net Link States (Area 0.0.0.3 [NSSA])

Link ID            ADV Router      Age  Seq#       LS-Age Routers
172.16.3.2/30      192.168.0.3      244 0x80000001    243 2

                Summary Link States (Area 0.0.0.3 [NSSA])

Link ID         ADV Router      Age  Seq#       LS-Age Route
0.0.0.0         192.168.0.1      245 0x80000001    245 0.0.0.0/0
10.10.20.0      192.168.0.1      237 0x80000001    237 10.10.20.0/24
10.10.40.0      192.168.0.1      237 0x80000001    237 10.10.40.0/24
172.16.0.0      192.168.0.1      245 0x80000001    245 172.16.0.0/30
172.16.4.0      192.168.0.1      245 0x80000001    245 172.16.4.0/30
192.168.0.1     192.168.0.1      240 0x80000001    240 192.168.0.1/32
192.168.0.2     192.168.0.1      237 0x80000001    237 192.168.0.2/32
192.168.0.4     192.168.0.1      237 0x80000001    237 192.168.0.4/32

                NSSA-external Link States (Area 0.0.0.3 [NSSA])

Link ID         ADV Router      Age  Seq#       LS-Age Route
10.10.10.0      192.168.0.1      243 0x80000004    246 E2 10.10.10.0/24      [0x0]
192.168.5.0     192.168.0.3      244 0x80000002    243 E2 192.168.5.0/28     [0x0]
192.168.6.0     192.168.0.3      244 0x80000002    243 E2 192.168.6.0/28     [0x0]

                Router Link States (Area 0.0.0.4 [Stub])

Link ID         ADV Router      Age  Seq#       LS-Age Link count
192.168.0.1     192.168.0.1      231 0x80000003    246 1
192.168.0.4     192.168.0.4      215 0x80000005    243 3

                Net Link States (Area 0.0.0.4 [Stub])

Link ID            ADV Router      Age  Seq#       LS-Age Routers
172.16.4.2/30      192.168.0.4      244 0x80000001    243 2

                Summary Link States (Area 0.0.0.4 [Stub])

Link ID         ADV Router      Age  Seq#       LS-Age Route
0.0.0.0         192.168.0.1      245 0x80000001    245 0.0.0.0/0
10.10.20.0      192.168.0.1      237 0x80000001    237 10.10.20.0/24
10.10.30.0      192.168.0.1      237 0x80000001    237 10.10.30.0/24
172.16.0.0      192.168.0.1      245 0x80000001    245 172.16.0.0/30
172.16.3.0      192.168.0.1      245 0x80000001    245 172.16.3.0/30
192.168.0.1     192.168.0.1      240 0x80000001    240 192.168.0.1/32
192.168.0.2     192.168.0.1      237 0x80000001    237 192.168.0.2/32
192.168.0.3     192.168.0.1      237 0x80000001    237 192.168.0.3/32

                AS External Link States

Link ID         ADV Router      Age  Seq#       LS-Age Route
10.10.10.0      192.168.0.1      243 0x80000004    246 E2 10.10.10.0/24      [0x0]
192.168.5.0     192.168.0.1      207 0x80000002    239 E2 192.168.5.0/28     [0x0]
192.168.6.0     192.168.0.1      207 0x80000002    239 E2 192.168.6.0/28     [0x0]

CPE2

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OSPF> show database

       OSPF Router with ID (192.168.0.2)(192.168.0.2)

                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       61 0x80000003     68 2
192.168.0.2     192.168.0.2       56 0x80000005     96 3

                Net Link States (Area 0.0.0.0)

Link ID            ADV Router      Age  Seq#       LS-Age Routers
172.16.0.2/30      192.168.0.2       68 0x80000001     68 2

                Summary Link States (Area 0.0.0.0)

Link ID         ADV Router      Age  Seq#       LS-Age Route
10.10.30.0      192.168.0.1       63 0x80000001     62 10.10.30.0/24
10.10.40.0      192.168.0.1       63 0x80000001     62 10.10.40.0/24
172.16.3.0      192.168.0.1       71 0x80000001     68 172.16.3.0/30
172.16.4.0      192.168.0.1       71 0x80000001     68 172.16.4.0/30
192.168.0.3     192.168.0.1       63 0x80000001     62 192.168.0.3/32
192.168.0.4     192.168.0.1       63 0x80000001     62 192.168.0.4/32

                ASBR-Summary Link States (Area 0.0.0.0)

Link ID         ADV Router      Age  Seq#       LS-Age
192.168.0.3     192.168.0.1       63 0x80000001     62

                AS External Link States

Link ID         ADV Router      Age  Seq#       LS-Age Route
10.10.10.0      192.168.0.1       69 0x80000004     68 E2 10.10.10.0/24      [0x0]
192.168.5.0     192.168.0.1       65 0x80000002     64 E2 192.168.5.0/28     [0x0]
192.168.6.0     192.168.0.1       65 0x80000002     64 E2 192.168.6.0/28     [0x0]

CPE3

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OSPF> show database

       OSPF Router with ID (192.168.0.3)(192.168.0.3)

                Router Link States (Area 0.0.0.3 [NSSA])

Link ID         ADV Router      Age  Seq#       LS-Age Link count
192.168.0.1     192.168.0.1      157 0x80000003    163 1
192.168.0.3     192.168.0.3      142 0x80000005    182 3

                Net Link States (Area 0.0.0.3 [NSSA])

Link ID            ADV Router      Age  Seq#       LS-Age Routers
172.16.3.2/30      192.168.0.3      163 0x80000001    163 2

                Summary Link States (Area 0.0.0.3 [NSSA])

Link ID         ADV Router      Age  Seq#       LS-Age Route
0.0.0.0         192.168.0.1      166 0x80000001    163 0.0.0.0/0
10.10.20.0      192.168.0.1      158 0x80000001    157 10.10.20.0/24
10.10.40.0      192.168.0.1      158 0x80000001    157 10.10.40.0/24
172.16.0.0      192.168.0.1      166 0x80000001    163 172.16.0.0/30
172.16.4.0      192.168.0.1      166 0x80000001    163 172.16.4.0/30
192.168.0.1     192.168.0.1      161 0x80000001    160 192.168.0.1/32
192.168.0.2     192.168.0.1      158 0x80000001    157 192.168.0.2/32
192.168.0.4     192.168.0.1      158 0x80000001    157 192.168.0.4/32

                NSSA-external Link States (Area 0.0.0.3 [NSSA])

Link ID         ADV Router      Age  Seq#       LS-Age Route
10.10.10.0      192.168.0.1      164 0x80000004    163 E2 10.10.10.0/24      [0x0]
192.168.5.0     192.168.0.3      163 0x80000002    182 E2 192.168.5.0/28     [0x0]
192.168.6.0     192.168.0.3      163 0x80000002    182 E2 192.168.6.0/28     [0x0]

                AS External Link States

Link ID         ADV Router      Age  Seq#       LS-Age Route
192.168.5.0     192.168.0.3      163 0x80000002    182 E2 192.168.5.0/28     [0x0]
192.168.6.0     192.168.0.3      163 0x80000002    182 E2 192.168.6.0/28     [0x0]

CPE4

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OSPF> show database

       OSPF Router with ID (192.168.0.4)(192.168.0.4)

                Router Link States (Area 0.0.0.4 [Stub])

Link ID         ADV Router      Age  Seq#       LS-Age Link count
192.168.0.1     192.168.0.1      194 0x80000003    205 1
192.168.0.4     192.168.0.4      176 0x80000005    216 3

                Net Link States (Area 0.0.0.4 [Stub])

Link ID            ADV Router      Age  Seq#       LS-Age Routers
172.16.4.2/30      192.168.0.4      205 0x80000001    205 2

                Summary Link States (Area 0.0.0.4 [Stub])

Link ID         ADV Router      Age  Seq#       LS-Age Route
0.0.0.0         192.168.0.1      208 0x80000001    205 0.0.0.0/0
10.10.20.0      192.168.0.1      200 0x80000001    199 10.10.20.0/24
10.10.30.0      192.168.0.1      200 0x80000001    199 10.10.30.0/24
172.16.0.0      192.168.0.1      208 0x80000001    205 172.16.0.0/30
172.16.3.0      192.168.0.1      208 0x80000001    205 172.16.3.0/30
192.168.0.1     192.168.0.1      203 0x80000001    202 192.168.0.1/32
192.168.0.2     192.168.0.1      200 0x80000001    199 192.168.0.2/32
192.168.0.3     192.168.0.1      200 0x80000001    199 192.168.0.3/32

...

Description

The routing tables of the wireless devices , contain entries about each subnet shown in the scheme. This means that the devices have successfully exchanged the routing information and added it to the FIB.

The main difference between the routing tables of the devices are the routes to the external networks: on some routers there is a direct route to the network, and on others a default route.

Note: the addresses of the loopback interfaces do not depend on the link state, therefore they can be used to manage the devices in redundant networks.

BS1

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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      172.16.3.2         UG3         0        0  rf5.0
10.10.40.0/24      172.16.4.2         UG3         0        0  rf5.0
127.0.0.1          127.0.0.1          UH          3      465  lo0
172.16.0.0/30      link#3             UC          0        0  rf5.0
172.16.3.0/30      link#3             UC          0        0  rf5.0
172.16.4.0/30      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        172.16.3.2         UGH3        0        0  rf5.0
192.168.0.4        172.16.4.2         UGH3        0        0  rf5.0
192.168.5.0/28     172.16.3.2         UG3         0        0  rf5.0
192.168.6.0/28     172.16.3.2         UG3         0        0  rf5.0
224.0.0.0/8        127.0.0.1          UGS         1    11852  lo0

CPE2

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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      172.16.0.1         UG3         0        0  rf5.0
10.10.40.0/24      172.16.0.1         UG3         0        0  rf5.0
127.0.0.1          127.0.0.1          UH          3      396  lo0
172.16.0.0/30      link#3             UC          0        0  rf5.0
172.16.3.0/30      172.16.0.1         UG3         0        0  rf5.0
172.16.4.0/30      172.16.0.1         UG3         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        172.16.0.1         UGH3        0        0  rf5.0
192.168.0.4        172.16.0.1         UGH3        0        0  rf5.0
192.168.5.0/28     172.16.0.1         UG3         0        0  rf5.0
192.168.6.0/28     172.16.0.1         UG3         0        0  rf5.0
224.0.0.0/8        127.0.0.1          UGS         1    15881  lo0

CPE3

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AS_3#1> netstat -r
Routing tables
Destination        Gateway            Flags     Refs     Use  Interface
default            172.16.3.1         UG3         0        0  rf5.0
10.10.10.0/24      172.16.3.1         UG3         0        0  rf5.0
10.10.20.0/24      172.16.3.1         UG3         0        0  rf5.0
10.10.30.0/24      link#2             UC          0        0  eth0
10.10.40.0/24      172.16.3.1         UG3         0        0  rf5.0
127.0.0.1          127.0.0.1          UH          3      534  lo0
172.16.0.0/30      172.16.3.1         UG3         0        0  rf5.0
172.16.3.0/30      link#3             UC          0        0  rf5.0
172.16.4.0/30      172.16.3.1         UG3         0        0  rf5.0
192.168.0.1        172.16.3.1         UGH3        0        0  rf5.0
192.168.0.2        172.16.3.1         UGH3        0        0  rf5.0
192.168.0.3        192.168.0.3        UH          0        0  lo0
192.168.0.4        172.16.3.1         UGH3        0        0  rf5.0
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     9339  lo0

CPE4

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AS_4#1> netstat -r
Routing tables
Destination        Gateway            Flags     Refs     Use  Interface
default            172.16.4.1         UG3         0        0  rf5.0
10.10.20.0/24      172.16.4.1         UG3         0        0  rf5.0
10.10.30.0/24      172.16.4.1         UG3         0        0  rf5.0
10.10.40.0/24      link#2             UC          0        0  eth0
127.0.0.1          127.0.0.1          UH          3      271  lo0
172.16.0.0/30      172.16.4.1         UG3         0        0  rf5.0
172.16.3.0/30      172.16.4.1         UG3         0        0  rf5.0
172.16.4.0/30      link#3             UC          0        0  rf5.0
192.168.0.1        172.16.4.1         UGH3        0        0  rf5.0
192.168.0.2        172.16.4.1         UGH3        0        0  rf5.0
192.168.0.3        172.16.4.1         UGH3        0        0  rf5.0
192.168.0.4        192.168.0.4        UH          0        0  lo0
224.0.0.0/8        127.0.0.1          UGS         1     3138  lo0

...

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