Cisco 7604 Configuration Manual page 39

Chapter 1 Product Overview
To prevent a significant volume of NAT traffic from being sent to the MSFC3, due to either a DoS
attack or a misconfiguration, enter the mls rate-limit unicast acl {ingress | egress} command
described at this URL:
http://www.cisco.com/en/US/docs/ios/security/command/reference/sec_m2.html#mls_rate-limit_u
nicast_acl
(CSCea23296)
With Release 12.2(18)SXE and later releases, IPv4 Multicast over point-to-point generic route
•
encapsulation (GRE) Tunnels—Refer to the publication at this URL:
http://www.cisco.com/en/US/docs/ios/12_2/interface/configuration/guide/icflogin.html
Releases earlier than Release 12.2(18)SXE support IPv4 multicast over point-to-point GRE tunnels
in software on the MSFC.
The PFC3 does not provide hardware acceleration for tunnels configured with the tunnel key command.
Note
GRE Tunneling and IP in IP Tunneling—The PFC3 and DFC3s support the following tunnel
•
commands:
–
–
–
–
–
–
Other supported types of tunneling run in software on the MSFC3.
The tunnel ttl command (default 255) sets the TTL of encapsulated packets.
The tunnel tos command, if present, sets the ToS byte of a packet when it is encapsulated. If the
tunnel tos command is not present and QoS is not enabled, the ToS byte of a packet sets the ToS
byte of the packet when it is encapsulated. If the tunnel tos command is not present and QoS is
enabled, the ToS byte of a packet as modified by PFC QoS sets the ToS byte of the packet when it
is encapsulated.
To configure GRE Tunneling and IP in IP Tunneling, refer to these publications:
http://www.cisco.com/en/US/docs/ios/12_2/interface/configuration/guide/icflogin.html
http://www.cisco.com/en/US/docs/ios/12_2/interface/command/reference/irfshoip.html
To configure the tunnel tos and tunnel ttl commands, refer to this publication:
http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/12s_tos.html
OL-4266-08
tunnel destination
tunnel mode gre
tunnel mode ipip
tunnel source
tunnel ttl
tunnel tos
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
Software Features Supported in Hardware by the PFC and DFC
1-5