Which option describes what the default RT filter indicates when you implement the BGP RT constrained route distribution feature?
A. A peer receives only a default route for each VRF.
B. A peer receives all routes, regardless of the RT value.
C. A peer receives routes only for RTs that are used on that router.
D. A peer receives no routes, regardless of the RT value.
B – is Correct
Default RT Filter
The default RT filter has a value of zero and length of zero. The default RT filter is used:
• By a peer to indicate that the peer wants all of the VPN routes sent to it, regardless of the RT value.
• By the RR to request that the PE advertise all of its VPN routes to the RR.
The default RT filter is created by configuring the neighbor default-originate command under the
address-family rtfilter unicast command. On the RR it comes as default along with the configuration of
route-reflector-client under the address-family rtfilter
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-3s/irg-xe-3s-book/irg-rt-filter.pdf
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