Shulou(Shulou.com)06/01 Report--

1. NSSA analysis of special area

Zone type function default route remarks commands stub filter LSA4, LSA5ABR default issue three types of default routes, seed cost value is 1 all routers in this area must be configured as stub, otherwise neighbors can not get up and cannot contain ASBR

Area 2 stub

Area 2 default-cost x

Totally stub filters three types of default routes issued by LSA3, LSA4 and LSA5ABR by default. The seed cost value is 1. All routers in this area must be configured as stub, otherwise neighbors cannot get up and cannot include ASBR,ABR configured as totally stbarea 2 stub no-summary.

NSSA filters remote LSA4 and LSA5, and local LSA4 and LSA5 are converted to LSA7 without sending default routes. Default routes need to be placed above and below ABR. All routers in this area must be configured as nssa, otherwise neighbors can't get up, including ASBR.

Area 2 nssa

Area 2 nssa default-information orig

2. Experimental topology

NSSA filters the LSA4 and LSA5 of remote R1, and the LSA4 and LSA5 of local R4 will be converted into LSA7. Because LSA7 can only exist in NSSA, it converts LSA7 to LSA5 on area boundary router R3. At this time, R4 cannot access the lo10:10.10.10.10 of R1 because NSSA filters the LSA4 and LSA5 of remote R1. Therefore, it is necessary to put the default route above and below R3, and the default route is type 7 route.

3. Experimental configuration

R1 configuration

Interface Loopback0

Ip address 1.1.1.1 255.255.255.0

Interface Loopback10

Ip address 10.10.10.10 255.255.255.0

Interface Serial0/0

Ip address 12.1.1.1 255.255.255.0

Serial restart-delay 0

Router eigrp 90

Network 10.10.10.0 0.0.0.255

No auto-summary

Router ospf 110

Router-id 1.1.1.1

Redistribute eigrp 90 subnets

Network 12.1.1.0 0.0.0.255 area 2

R2 configuration

Interface Loopback0

Ip address 2.2.2.2 255.255.255.0

Interface Serial0/0

Ip address 12.1.1.2 255.255.255.0

Interface Serial0/1

Ip address 23.1.1.2 255.255.255.0

Router ospf 110

Router-id 2.2.2.2

Log-adjacency-changes

Network 12.1.1.0 0.0.0.255 area 2

Network 23.1.1.0 0.0.0.255 area 0

R3 configuration

Interface Loopback0

Ip address 3.3.3.3 255.255.255.0

Interface Serial0/0

Ip address 34.1.1.3 255.255.255.0

Interface Serial0/1

Ip address 23.1.1.3 255.255.255.0

Router ospf 110

Router-id 3.3.3.3

Network 23.1.1.0 0.0.0.255 area 0

Network 34.1.1.0 0.0.0.255 area 1

R4 configuration

Interface Loopback0

Ip address 4.4.4.4 255.255.255.0

Interface Serial0/0

Ip address 34.1.1.4 255.255.255.0

Interface Serial0/1

Ip address 45.1.1.4 255.255.255.0

Router ospf 110

Router-id 4.4.4.4

Redistribute rip subnets

Network 34.1.1.0 0.0.0.255 area 1

Router rip

Version 2

Network 45.0.0.0

No auto-summary

R5 configuration

Interface Loopback0

Ip address 5.5.5.5 255.255.255.0

Interface Serial0/1

Ip address 45.1.1.5 255.255.255.0

Router rip

Version 2

Network 5.0.0.0

Network 45.0.0.0

No auto-summary

4. Experimental verification.

Filter remote LSA4 and LSA5, and convert local LSA4 and LSA5 to LSA7

Before configuring NSSA

After configuring NSSA

LSA7 is converted to LSA5 again

Manually delegate the default rout

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