http://www.cisco.com/en/US/docs/ios/sec_user_services/configuration/guide/sec_loc_aaa_srvr_ps6441_TSD_Products_Configuration_Guide_Chapter.html

RFC 4274 (INFORMATIONAL)BGP uses the IP TTL value to protect its External BGP (EBGP) sessions from any TCP- or IP-based CPU-intensive attacks. It is a simple mechanism that suggests the use of filtering BGP (TCP) segments, using the IP TTL value car...

It is a "security" feature described in RFC 5082 (most recent).http://www.rfc-editor.org/rfc/rfc5082.txt

Platform with mixed classic and fabric-enabled modules will operate in truncated mode, in which classic cards will send entire frame over shared bus and fabric-enabled modules will send truncated frames (32 bytes header + 64 bytes payload needed for ...