Which three methods can a network engineer use to fix a metric based routing loop in the network? (Choose three)
A. Implement offset lists at network boundaries
B. Filter routes manually using distribute lists
C. Filter routes manually using prefix lists
D. Implement proper network summarisation on key routing points
E. Filter routes based on tags
F. Utilise root database filters
Metric based loops are the easiest to prevent by filtering the routes at the redistribution points. We can apply a Tag to the route or manually specific ACL and prefix list on what routes we don’t want to redistribute.
http://packetpath.blogspot.com/2014/05/routing-loops-overview-eigrp-route-loop.html
ABD?
(to fix a metric based routing loop -> Which can change the metric?)
・able to change metrics
distribute-list
http://www.ciscopress.com/articles/article.asp?p=2273507
Offset-list
http://www.ciscopress.com/articles/article.asp?p=1613547&seqNum=2
Summary metric
https://community.cisco.com/t5/networking-documents/how-the-eigrp-summary-route-metric-is-determined/ta-p/3153842
・Unable to change metrics
Prefix-list
https://www.cisco.com/c/m/en_us/techdoc/dc/reference/cli/nxos/commands/bgp/ip-prefix-list.html
Tag
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_eigrp/configuration/xe-3s/ire-xe-3s-book/ire-en-rou-tags.html
Database-filter
https://learningnetwork.cisco.com/thread/42774
It should ABE.
I’m sure about B and E. But the third not sure. I choose C.
I agree, more likely, BCE
I think C is a trick answer.
Once can’t actually filter routes directly using a prefix list, you will need to apply it to a route map or distribute list.