Routers R1, R2, R4, R6, R7  and R8 area IOS routers. 

Routers R3 and R5 are IOS-XR. 

1. Configure router R8 in ISIS area 49.0002

2. Configure routers R4, R5, R6 and R7 in ISIS area 49.0003

3. Routers R6 and R7 should only have ISIS Level-1 database.  

4. Routers R4 and R5 should only form Level-1 adjacency online R4-R5. 

5. Traffic flowing between Area 2 and Area 3 (both directions) should NOT use link R1-R2, if alternative path is available.
6. Create interface Loopback100 on R3. Configure ipv4 address 100.100.100.100/32 on this interface. All devices in the topology should have connectivity to this interface. Do not use redistribution.
7. On link R1-R8, authenticate ISIS Hello's using password HPASS. The password should be visible in the configuration file.
8. Authenticate LSPs and SNPs in area 3 using password AREA3. Don't use "authentication" command on routers R6 and R7.
9. Authenticate Level-2 LSPs and SNPs using password DPASS. Use strongest authentication method. Configuration shall allow for easy key management in the future.

Solution:

Highlight the text below to reveal the solution. 

This task requires understanding of multi-level ISIS, metrics, injection of default route into Level-2 and different authentication types. 

Requirement #3 -  configure R6 and R7 for ISIS level-1 only on protocol level, so Level-2 database is not created. 

Requirement #5 -  increase the ISIS metric on link R1-R2. 

Requirement #6 -  configure R3 to inject a default route into ISIS Level-2 domain. 

Requirement #7 - use clear text (old style) interface authentication.

Requirement #8 - since authentication command not allowed on R6 and R7, use area-password configuration (old style). Routers R4 and R5 require new style configuration with "text" keyword, for compatibility with old style configuration of R6 and R7. 

Requirement #9 - Use new style authentication, level-2, MD5 with key-chains for easy key management. 

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