Specifications

61
Release Notes for Cisco 7000 Family for Cisco IOS Release 12.1 T
78-10811-05
New and Changed Information
TN3270 Server Connectivity Enhancements
Platforms: Cisco 7200 series and Cisco 7500 series routers
The TN3270 Server Connectivity Enhancements feature, an enhancement to the existing TN3270
Server feature, provides the following new functions:
• Dynamic LU naming
• Inverse DNS nailing
• TN3270 Server security enhancements
Traceroute Enhancement for MPLS
Platforms: Cisco 7200 series and Cisco 7500 series routers
The traceroute enhancements for MPLS feature introduces two new commands that enable you to
manage the time to live (TTL) field in an MPLS header.
• The mpls ip ttl-expiration pop command lets you specify how a packet with an expired time to
live (TTL) value is forwarded. You can specify that the packet be forwarded by the global IP routing
table or by the packet’s original label stack. The forwarding method is determined by the number
of labels in the packet. You specify the number of labels as part of the command. If the packet
contains the same or fewer labels than you specified, it is forwarded through the use of the global
IP routing table. If the packet contains more labels than you specified, the packet is forwarded
through the use of the original label stack.
• The mpls ip propagate-ttl command controls the generation of the time to live (TTL) field in the
MPLS header when labels are first added to an IP packet. By default, this command is enabled,
which means the TTL field is copied from the IP header. The command allows a traceroute
command to show all the hops in the network.
Use the no form of the mpls ip propagate-ttl command to use a fixed TTL value (255) for the first
label of the IP packet. This hides the structure of the MPLS network from a traceroute command.
You can specify the types of packets to be hidden by using the forwarded and local arguments.
Specifying no mpls ip propagate-ttl forwarded allows the structure of the MPLS network to be
hidden from customers but not from the provider. This is the most common application of the
command.
Class Based Policer for the DiffServ AF PHB
Platforms: Cisco 7200 series
Traffic policing is used to control the rate of traffic flowing across an interface.
The Class Based Policer for the DiffServ AF PHB feature performs the following functions:
• Limits the input or output transmission rate of a class of traffic based on user-defined criteria
• Marks packets by setting the IP precedence value, the Quality of Service (QoS) group, or the
differentiated services code point (DSCP) value
For additional information on the Traffic Policing feature, see the Traffic Policing feature module on
Cisco.com and on the Documentation CD-ROM.