ok. GD is Anomaly Guard Module , This module is seated in C6509 MSFC, When Attack Start , GD will float static route to MSFC and then MSFC BGP announce to Peer device,

R3 Running IBGP, IGP, and RX is External Router to redirect traffic when attack from ISP1, RED link is BGP announce Route( Guard floating static route = zone )

the attack is DDoS, Anomaly Guard Module depends these attacks. like TCP Syn Flooding,

UDP Flooding, When Attack starts, I would like to update bgp announce directly ISP, To protecting our Real Traffic.

Hello Seungyeop,

I would suggest to read abuot remote black hole triggering

http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6586/ps6642/prod_white_paper0900aecd80313fac.pdf

Hope to help

Giuseppe