A generated route is used to create a route of last resort when BGP routes from the 10.0.0.0/23
block are present. Given the following output, which next hop will be used as the forwarding next
hop for the generated route?
A.
172.16.0.2
B.
172.16.0.6
C.
172.16.0.10
D.
172.16.0.14
Explanation:
Answer is not presented in this question
1) best preference chosen first
2) in a tie, lowest IP address – which is 0.0.0.0 in this question, but the generated route is only for the range of 10.0.0.0 – 10.0.1.255, so the default route doesnt go under the summary anyway.
all other options have the same IP address.
3) in a tie, smallest prefix length will bechosen – since 10.0.0.0/23 has the smallest prefix length, then it should be the contributing route for setting the next-hop for the generated route, which would be 172.16.0.8, but this answer doesn’t present in the options so none of the answers are valid for the question.
see this link:
https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/policy-edit-routing-options.html
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My mistake, the quetsion says “last resort route” = 0.0.0.0/0, therefore answer C should be chosen as the generated route is a 0.0.0.0/0 which indeed included inside a default route of 0.0.0.0/0.
set routing-options generate 0.0.0.0/0
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gotta corerct myself again :[
a generated route cannot be generated from an default route.
I labbed it, and if you want to create a default generated route of 0.0.0.0/0, and a default route is already exists with a valid next-hop, then the generated route will ignore it and will use the next prefix which summarized under our generated route with his next-hop for the generated route as follow:
1) lowest preference value prefix
2) if tie, lowest IP address prefix
3) if tie, smallest prefix length.
therefore this the question we have 3 prefixes which aren’t a default route, they both have the same preference and the same IP address, so the prefix with the smalles prefix length should be chosen as the next-hop for the generated route, which is 10.0.0.0/23’s next-hop which dosn’t appear as an option.
conclusion:
the real and accurate answer for thsi question isn’t available, none of the answers are correct!
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