User guide

Release Notes for Cisco 2500 Series for Cisco IOS Release 12.0 T 25

New Software Features in Release 12.0(1)T

The following new software enhancements are supported by the Cisco 2500 series in

Release 12.0(1)T.

RSM/TR-VLAN

The Token Ring VLAN support on the Route Switch Module (RSM) enables a Catalyst 5000 switch

to provide the functionality of bridging and multi-protocol routing for Token Ring VLANs. The

installation of an RSM in a Catalyst 5000 supplements the existing switching capabilities with the

functionality of a standalone router that performs inter-VLAN routing and bridging. If the Token

Ring RSM is associated with a VIP2 board, it provides direct external network connections through

a variety of media using the standard port adapters on the VIP2 and offers functionality similar to a

Cisco 7500 series router.

The RSM module can either route or bridge Token Ring packets, thereby functioning as a router or

as a bridge. In Cisco IOS Release 12.0(1)T, both APPN and DLSW+ are supported on the RSM's

Token Ring VLANs. RSRB, however, is not supported on the RSM.

IOS IEEE 802.1Q Support

Cisco IOS IEEE 802.1Q provides support for IEEE 802.1Q encapsulation for Virtual LANs

(VLANs). Use this feature for VLANs consisting of IEEE 802.1Q compliant switches.

Mobile IP

Mobile IP provides users the freedom to roam beyond their home subnet while consistently

maintaining their home IP address. This enables transparent routing of IP datagrams to mobile users

during their movement, so that data sessions can be initiated to them while they roam; it also enables

sessions to be maintained in spite of physical movement between points of attachment to the Internet

or other networks. Cisco’s implementation of Mobile IP is fully compliant with the Internet

Engineering Task Force’s (IETF’s) proposed standard deﬁned in Request for Comments

(RFC) 2002.

Easy IP Phase 2-DHCP Server

With the introduction of Easy IP Phase 2, Cisco IOS software also supports Intelligent DHCP Relay

functionality. A DHCP Relay Agent is any host that forwards DHCP packets between clients and

servers. A DHCP Relay Agent enables the client and server to reside on separate subnets. If the

Cisco IOS DHCP server cannot satisfy a DHCP request from its own database, it can forward the

DHCP request to one or more secondary DHCP servers deﬁned by the network administrator using

standard Cisco IOS ip helper-address functionality.

Smart-init (Mars FE2P)

The smart-init feature is an extension to the existing memory split program of the Cisco IOS

software running on Cisco 3600 series routers. It computes iomem size by looking at the network

modules installed in the system and uses this iomem for carrying out the memory split. Also,

compatibility with older IOS conﬁgurations is maintained by retaining support for the memory-size

conﬁguration command. The user can disable smart-init and set iomem percentage to the required

value by issuing the memory-size conﬁguration command.