Table Of Contents
Release Notes for Cisco 1600 Series for Cisco IOS Release 12.0 T
Determining the Software Version
Upgrading to a New Software Release
New Software Features in Release 12.0(7)T
Dynamic Multiple Encapsulations for Dial-In over ISDN
Multicast Source Discovery Protocol
X.25 Switch Local Acknowledgment
New Software Features in Release 12.0(5)T
Frame Relay End-to-End Keepalive
Layer 2 Tunneling Protocol Dial-out
Web Cache Communications Protocol Version 2 (WCCPv2)
No New Software Features in Release 12.0(4)T
New Software Features in Release 12.0(3)T
Annex-G (X.25 over Frame Relay)
DLSw+ RSVP Bandwidth Reservation
Fancy Queuing on Frame Relay for Cisco HDLC
SLIP-PPP Banner and Banner Tokens
No New Software Features in Release 12.0(2)T
New Software Features in Release 12.0(1)T
Layer Two Tunneling Protocol (L2TP)
Last Maintenance Release of Cisco IOS Release 12.0 T
Caveat CSCdr91706 and IOS HTTP Vulnerability
Affected Devices and Software Versions
Cisco IOS Software Documentation Set
Release 12.0 Documentation Set
Obtaining Technical Assistance
Software Configuration Tips on the Cisco Technical Assistance Center Home Page
Release Notes for Cisco 1600 Series for Cisco IOS Release 12.0 T
December 13, 1999
Note
Update, May 2003: The Cisco 1600 Series has reached End-of-Sale (EoS) status as of February 2003; it cannot be ordered and may no longer be supported. The Cisco 1700 Series are the recommended replacement products.
Note
These release notes for Cisco 1600 series support Cisco IOS Release 12.0 T, up to and including Release 12.0(7)T. These release notes describe new features, memory requirements, hardware support, software platform deferrals, and changes to the microcode or modem code and related documents.
For a list of the software caveats that apply to Release 12.0(7)T, see the Caveats for Cisco IOS Release 12.0 T document that accompanies these release notes. The caveats document is updated for every maintenance release and is located on Cisco Connection Online (CCO) and the Documentation CD-ROM.
Use these release notes with Cross-Platform Release Notes for Cisco IOS Release 12.0 on CCO and the Documentation CD-ROM.
Contents
These release notes describe the following topics:
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System Requirements
This section describes the system requirements for Release 12.0 T:
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Memory Requirements
Table 1 Memory Requirements for Cisco 1600 Series Routers
Cisco 1600-
Cisco 1604IP Feature Sets
IP
c1600-y-l
6 MB
4 MB
Flash
IP Plus
c1600-sy-l
8 MB
4 MB
Flash
IP Plus 40
c1600-sy40-l
82 MB
4 MB
Flash
IP Plus 56
c1600-sy56-l
82 MB
4 MB
Flash
IP Plus IPSEC 56
c1600-sy56i-l
8 MB
6 MB
Flash
IP/IPX
c1600-ny-l
8 MB
4 MB
Flash
IP/IPX/AT/IBM
c1600-bnr2y-l
12 MB
4 MB
Flash
IP/IPX/AT/IBM Plus
c1600-bnr2sy-l
12 MB
6 MB
Flash
IP/FW
c1600-oy-1
127 MB
63 MB
Flash
IP/IPX/FW Plus
c1600-nosy-l
124 MB
65 MB
Flash
IP/FW Plus IPSEC 56
c1600-osy56i-l
124 MB
6 MB
Flash
IP/IPX/AT/IBM/FW Plus IPSEC 56
c1600-bnor2sy56i-l
166 MB
87 MB
Flash
Cisco 1601-R - 1605-R
IP Feature Sets
IP
c1600-y-mz
4 MB
8 MB
RAM
IP Plus
c1600-sy-mz
4 MB
10 MB
RAM
IP Plus 40
c1600-sy40-mz
4 MB
10 MB
RAM
IP Plus 56
c1600-sy56-mz
4 MB
128 MB
RAM
IP Plus IPSEC 56
c1600-sy56i-mz
4 MB
12 MB
RAM
IP/IPX
c1600-ny-mz
4 MB
8 MB
RAM
IP/IPX/AT/IBM
c1600-bnr2y-mz
4 MB
12 MB
RAM
IP/IPX/AT/IBM Plus
c1600-bnr2sy-mz
6 MB
16 MB
RAM
IP/FW
c1600-oy-mz
4 MB
164 MB
RAM
IP/IPX/FW Plus
c1600-nosy-mz
69 MB
168 MB
RAM
IP/FW Plus IPSEC 56
c1600-osy56i-mz
69 MB
166 MB
RAM
IP/IPX/AT/IBM/FW Plus IPSEC 56
c1600-bnor2sy56i-mz
6 MB
2410 MB
RAM
1 Release 12.0 T features sets were not available for the Cisco 1600 series until Release 12.0(3)T.
2 6 MB in Release 12.0(3)T and earlier.
3 4 MB in Release 12.0(5)T. 6 MB in Release 12.0(4)T and earlier.
4 8 MB in Release 12.0(5)T and earlier.
5 4 MB in Release 12.0(5)T. 12 MB in Release 12.0(4)T and earlier.
6 12 MB in Release 12.0(5)T and earlier.
7 6 MB in Release 12.0(5)T and earlier.
8 10 MB in Release 12.0(5)T and earlier.
9 4 MB in Release 12.0(5)T and earlier.
10 16 MB in Release 12.0(5)T and earlier.
Hardware Supported
Cisco IOS Release 12.0 T supports the Cisco 1600 series:
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Cisco 1600 series routers have two memory architectures: one run-from-Flash (RFF) and one run-from RAM (RFR). Router model names with an R are RFR routers; all other models are RFF. In this document, model names without an R refer to both RFF and RFR models, except where otherwise noted.
For detailed descriptions of the new hardware features, see the "New and Changed Information" section.
Table 2 lists the interfaces supported on the Cisco 1600 series. For more complete information, see the "Overview of the Router" chapter in the Cisco 1600 Series Hardware Installation Guide.
Determining the Software Version
To determine the version of Cisco IOS software running on your Cisco 1600 series, log in to the router and enter the show version EXEC command:
router> show versionCisco Internetwork Operating System SoftwareIOS (tm) 1600 Software (C1600-NY-L), Version 12.0(7)T, RELEASE SOFTWAREUpgrading to a New Software Release
For information on upgrading to a new software release, see the product bulletin Cisco IOS Software Release 12.0 T Upgrade Paths and Packaging Simplification (#819: 1/99) on CCO at:
Technical Documents: Product Bulletins: Software
Under Cisco IOS 12.0, click Cisco IOS Software Release 12.0 T Upgrade (#819: 1/99).
Feature Set Tables
The Cisco IOS software is packaged in feature sets consisting of software images—depending on the platform. Each feature set contains a specific set of Cisco IOS features.
Release 12.0 T supports the same feature sets as Release 12.0, but Release 12.0 T can include new features supported by the Cisco 1600 series.
Caution
Table 3 and Table 4 list the features and feature sets supported by the Cisco 1600 series in Cisco IOS Release 12.0 T and use the following conventions:
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Note
New and Changed Information
The following sections list the new hardware and software features supported by the Cisco 1600 series for Release 12.0 T:
New Software Features in Release 12.0(7)T
The following new software enhancements are supported by the Cisco 1600 series for Release 12.0(7)T and later releases:
Dynamic Multiple Encapsulations for Dial-In over ISDN
The Dynamic Multiple Encapsulations feature allows incoming calls over ISDN to be assigned an encapsulation type such as Frame Relay, PPP, and X.25 based on calling line identification (CLID) or DNIS. It also allows various encapsulation types and per-user configurations on the same ISDN B channel at different times according to the type of incoming call.
The Dynamic Multiple Encapsulations feature allows per-user configuration for each dial-in caller on any ingress ISDN B channel on which encapsulation can be run independently from other B channels on the same ISDN link. The caller is identified by CLID (caller ID) or DNIS to ensure that only incoming calls with authorization and valid user profiles are accepted. When PPP is used, authentication and profile binding can also be done by PPP name.
In addition, a large set of user profiles can be stored in dialer profiles locally or on a remote AAA server. (For large scale dial-in, storing user-specific configurations on a remote server becomes necessary for enhancing expandability and local memory efficiency.) However, whether stored locally or on a remote AAA server, the user-specific encapsulation and configuration can be applied to individual B channels dynamically and independently.
Dynamic multiple encapsulation is especially important in Europe where ISDN is relatively inexpensive and maximum use of all 30 B channels on the same ISDN link is desirable. Further, the feature removes the need to statically dedicate channels to a particular encapsulation and configuration type, and improves channel usage.
Low Latency Queueing
The Low Latency Queueing feature brings strict priority queueing to Class-Based Weighted Fair Queueing (CBWFQ). Strict priority queueing allows delay-sensitive data, such as voice, to be dequeued and sent first (before packets in other queues are dequeued), giving delay-sensitive data preferential treatment over other traffic.
Without Low Latency Queueing, CBWFQ provides weighted fair queueing based on defined classes with no strict priority queue available for real-time traffic. CBWFQ allows you to define traffic classes and then assign characteristics to that class. For example, you can designate the minimum bandwidth delivered to the class during congestion.
For CBWFQ, the weight for a packet belonging to a specific class is derived from the bandwidth you assigned to the class when you configured it. Therefore, the bandwidth assigned to the packets of a class determines the order in which packets are sent. All packets are serviced fairly based on weight; no class of packets may be granted strict priority.This scheme poses problems for voice traffic that is largely intolerant of delay, especially variation in delay. For voice traffic, variations in delay introduce irregularities of transmission manifesting as jitter in the heard conversation.
The Low Latency Queueing feature provides strict priority queueing for CBWFQ, reducing jitter in voice conversations. Configured by the priority command, Low Latency Queueing enables use of a single, strict priority queue within CBWFQ at the class level, allowing you to direct traffic belonging to a class to the CBWFQ strict priority queue.
In the event of congestion, when the bandwidth is exceeded policing is used to drop packets. Voice traffic enqueued to the priority queue is UDP-based and therefore not adaptive to the early packet drop characteristic of Weighted Random Early Detection (WRED).
When congestion occurs, traffic destined for the priority queue is metered to ensure that the bandwidth allocation configured for the class to which the traffic belongs is not exceeded.
Multicast Source Discovery Protocol
Multicast Source Discovery Protocol (MSDP) connects multiple PIM sparse-mode (SM) domains. MSDP allows multicast sources for a group to be known to all rendezvous points (RPs) in different domains. Each PIM-SM domain uses its own RPs and need not depend on RPs in other domains. An RP runs MSDP over TCP to discover multicast sources in other domains.
An RP in a PIM-SM domain has an MSDP peering relationship with MSDP-enabled routers in another domain. The peering relationship occurs over a TCP connection, where primarily a list of sources sending to multicast groups is exchanged. The TCP connections between RPs are achieved by the underlying routing system. The receiving RP uses the source lists to establish a source path.
The purpose of this topology is to have domains discover multicast sources in other domains. If the multicast sources are of interest to a domain that has receivers, multicast data is delivered over the normal, source-tree building mechanism in PIM-SM.
MSDP is also used to announce sources sending to a group. These announcements must originate at the domain's RP.
MSDP depends heavily on (M)BGP for interdomain operation. You should run MSDP in your domain's RPs that act as sources, sending to global groups for announcement to the Internet.
Policy Routing with CEF
IP policy routing now works with Cisco Express Forwarding (CEF), Distributed CEF (dCEF), and NetFlow. IP policy routing was formerly supported only in fast-switching and process-switching. Now that policy routing is integrated into CEF, policy routing can be deployed on a wide scale and on high-speed interfaces.
X.25 Closed User Groups
The X.25 specification for Closed User Groups (CUG):
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Note
X.25 Switch Local Acknowledgment
Cisco offers an X.25 switch function that creates virtual connections (VC) by connecting channels between X.25 class services.
The following X.25 class services are supported:
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The current Cisco implementation provides end-to-end acknowledgment, which means that flow control or window and packet size acknowledgment is between the originating and terminating data terminal equipment (DTE).
Acknowledgment is not local to the DTE and data communications equipment (DTE), and the overall effect is low throughput.
VPN Tunnel Management
The VPN Tunnel Management feature provides network administrators with two new functions for managing VPN tunnels:
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These functions can be used on either end of a VPN tunnel—the Network Access Server (NAS) or on the home gateway.
When this feature is enabled, Multichassis Multilink PPP (MMP) Layer 2 Forwarding (L2F) tunnels can still be created and established.
New Software Features in Release 12.0(5)T
The following new software enhancements are supported by the Cisco 1600 series in Release 12.0(5)T and later releases.
DNS-Based X.25 Routing
Managing a large TCP/IP network requires accurate and up-to-date maintenance of IP addresses and X.121 address mapping information on each router database in the network. Currently, this data is managed manually. Because these addresses are constantly being added and removed in the network, the routing table of every router frequently needs to be updated, which is a time-consuming and error-prone task.
X.25 has long operated over an IP network, specifically using Transmission Control Protocol (TCP) as a reliable transport mechanism. This method is known as X.25 over TCP (XOT). However, large networks and financial legacy environments experienced problems with the amount of route configuration that needed to be performed manually because each router switching calls over TCP needed every destination configured. Every destination from the host router needed a static IP route statement, and for larger environments, these destinations could be as much as several thousand per router. Until now, the only way to map X.121 addresses and IP addresses was on a one-to-one basis using the x25 route x121address xot ipaddress command.
The solution to this problem was to centralize route configuration that routers could then access for their connectivity needs. This centralization is the function of the DNS-Based X.25 Routing feature, because the DNS server is a database of all domains and addresses on a network.
DSLw+ Ethernet Redundancy
The DLSw+ Ethernet Redundancy feature provides redundancy in an Ethernet environment. It enables DLSw+ to support parallel paths between two points in an Ethernet environment, ensuring resiliency in the case of a router failure and providing load balancing for traffic load.
DLSw+ could provide redundancy prior to this feature in a Token Ring environment or via backup peers. When an end station on an Ethernet LAN had multiple active paths into a DLSw+ network, problems occurred.
Redundancy is not possible in an Ethernet environment because, unlike Token Ring, it does not have a RIF field in its packet. The RIF notifies a router of the path a packet has traveled by tracking each ring number and bridge it travels along a path. If a bridge notices that the next ring matches a ring already in the RIF, then the frame is not copied on to that ring. The RIF prevents unreliable local reachability information, circuit contention, and undetected looping explorers.
Frame Relay End-to-End Keepalive
The Frame Relay End-to-End Keepalive feature enables the router to keep track of permanent virtual circuit (PVC) status, independent of the switches in the Frame Relay network. The routers at both ends of a PVC in a Frame Relay network engage in a keepalive session where one router issues keepalive messages and the router at the other end of the PVC connection responds. The time interval for the keepalive is configurable and is enabled on a per-PVC basis. As long as the keepalive-issuing router receives response messages, the PVC status is up. When response messages are not received (because of line failure, a faulty switch in the Frame Relay network, or a router failure), the PVC is down. This mechanism enables bidirectional communication of PVC status to both routers at the ends of a PVC connection.
Firewall Feature Set
The Cisco IOS Firewall feature set, available for a wide range of Cisco router platforms, adds greater depth and flexibility to existing Cisco IOS software security capabilities, enriching features such as authentication, encryption, and failover with robust firewall functionality and intrusion detection. A Cisco IOS software-based, integrated firewall solution scales to meet the bandwidth and performance requirements of any network. It also maximizes a Cisco router investment by combining multiprotocol routing functionality with sophisticated security policy enforcement throughout the network.
The Cisco IOS Firewall feature set delivers cost-effective perimeter security packaged with advanced features like stateful, application-based filtering, dynamic per-user authentication and authorization, defense against network attacks, Java blocking, and real-time alerts. Because it is completely interoperable with Cisco IOS software features including NAT, VPN tunneling protocols, Cisco Express Forwarding (CEF), AAA extensions, Cisco encryption technology, and Cisco IOS IPSec, It is a complete, integrated VPN solution.
Layer 2 Tunneling Protocol Dial-out
The Layer 2 Tunneling Protocol (L2TP) Dial-Out feature enables L2TP Network Servers (LNSs) to tunnel dial-out VPDN calls using L2TP as the tunneling protocol. This feature enables a centralized network to efficiently and inexpensively establish a virtual point-to-point connection with any number of remote offices.
Using the L2TP Dial-Out feature, Cisco routers can carry both dial-in and dial-out calls in the same L2TP tunnels.
Previously, only dial-in VPDN calls were supported.
L2TP dial-out involves two devices: an LNS and an L2TP Access Concentrator (LAC). When the LNS wants to perform L2TP dial-out, it negotiates an L2TP tunnel with the LAC. The LAC then places a PPP call to the client(s) the LNS wants to dial-out to.
Multicast Routing Monitor
The Multicast Routing Monitor (MRM) feature is a management diagnostic tool that provides network fault detection and isolation in a large multicast routing infrastructure. It is designed to notify a network administrator of multicast routing problems in near real time.
MRM has three components that play different roles: the Manager, the Test Sender, and the Test Receiver. The Manager can reside on the same device as the Test Sender or Test Receiver. You can test a multicast environment using test packets (perhaps before an upcoming multicast event), or you can monitor existing IP multicast traffic.
You create a test based on various test parameters, name the test, and start the test. The test runs in the background and the command prompt returns. If the Test Receiver detects an error (such as packet loss or duplicate packets), it sends an error report to the router configured as the Manager. The Manager immediately displays the error report. Also, by issuing a certain show command, you can see the error reports, if any. You then troubleshoot your multicast environment as normal, perhaps using the mtrace command from the source to the Test Receiver. If the show command displays no error reports, the Test Receiver is receiving test packets without loss or duplicates from the Test Sender.
PGM Router Assist
The PGM Router Assist feature allows Cisco routers to support the optimal operation of Pragmatic General Multicast (PGM). The PGM Reliable Transport Protocol itself is implemented on the hosts of the customer.
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Service Assurance Agent
The Service Assurance (SA) Agent is both an enhancement to and a new name for the Response Time Reporter (RTR) feature that was introduced in Cisco IOS Release 11.2. The feature allows you to monitor network performance by measuring key Service Level Agreement metrics such as response time, network resources, availability, jitter, connect time, packet loss, and application performance.
With Cisco IOS Release 12.0(5)T, the SA Agent provides new capabilities that enable you to:
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Web Cache Communications Protocol Version 2 (WCCPv2)
The Web Cache Communications Protocol enables Cisco IOS routing platforms to transparently redirect content requests (for example, web requests) from clients to a locally connected Cisco Cache Engine (or Cache Cluster) instead of the intended origin server. When a Cache Engine receives such a request, it attempts to service it from its own local cache if the requested information is present. If not, the Cache Engine issues its own request to the originally requested origin server to get the required information. When the Cache Engine retrieves the requested information, it forwards it to the requesting client and caches it to fulfill future requests, thus maximizing download performance and significantly reducing WAN transmission costs.
WCCPv2 provides enhancements to WCCPv1, including:
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X.25 Remote Failure Detection
Static routes are used over a packet-switched data network in order to reduce volume-based costs of the network. Until now, if two routers were connected via multiple X.25 links (a primary and a secondary), a router could not detect failure of the primary link. If a failure occurred, the data was not transferred to the second link because X.25 was unable to determine whether remote links were up or down. Therefore X.25 could not use an alternate connection to a destination.
The X.25 Remote Failure Detection feature is important for X.25 users because now, after a primary link failure, the router can establish a secondary link and continue sending data. This feature is a way for the router to detect a call failure and to use a secondary route to send subsequent packets to the remote destination, at the same time as making periodic attempts to reconnect to its primary link.
No New Software Features in Release 12.0(4)T
There are no new features supported by the Cisco 1600 series in Cisco IOS Release 12.0(4)T.
New Software Features in Release 12.0(3)T
The following new software enhancements are supported by the Cisco 1600 series in Release 12.0(3)T and later releases.
Annex-G (X.25 over Frame Relay)
Annex G (X.25 over Frame Relay) facilitates the migration from an X.25 backbone to a Frame Relay backbone by permitting encapsulation of CCITT X.25/X.75 traffic within a Frame Relay connection. Annex G has developed to accommodate the many Cisco customers in Europe, where X.25 still is a popular protocol. With Annex G, the process of transporting X.25 over Frame Relay has been simplified, by allowing direct X.25 encapsulation over a Frame Relay network.
This simple process is largely achieved using X.25 profiles (similar to dialer profiles), which were created to streamline the configuration of X.25 on a per DLCI basis. X.25 profiles can contain any existing X.25 command and, once created and named, can be simultaneously associated with more than one Annex G DLCI connection, just using the profile name.
CDP Additions for Cisco IOS
The Cisco Discovery Protocol (CDP) is a media-independent device discovery protocol that runs on all cisco manufactured equipment, including routers, bridges, access servers, and switches. Each device sends periodic messages to a multicast address. Each device listens to the periodic messages sent by others in order to learn about neighboring devices and determine when their interfaces to the media go up or down. With CDP, network management applications can learn the device type and the SNMP agent address of neighboring devices. This process enables applications to send SNMP queries to neighboring devices.
CDP runs on all media that support Subnetwork Access Protocol (SNAP), including local-area network (LAN), Frame Relay, and Asynchronous Transfer Mode (ATM) media. CDP runs over the data link layer only. Therefore, two systems that support different network-layer protocols can learn about each other.
Each device configured for CDP sends periodic messages to a multicast address. Each device advertises at least one address at which it can receive SNMP messages. The advertisements also contain time-to-live, or holdtime, information, which indicates the time a receiving device should hold CDP information before discarding it.
Additions for Cisco Discovery Protocol (CDP) include the following:
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The benefits include, transparent support of X.25 encapsulation over the Frame Relay network; direct X.25 configurations on a per DLCI basis; multiple Annex G DLCIs can use the same X.25 profile; multiple logical X.25 SVCs per Annex G link, and the fact that Cisco routers already contain the functionality necessary to perform the framing and frame removal required by Annex G.
DLSw+ Enhanced Load Balancing
In a network with multiple capable paths, the DLSw+ Load Balancing Enhancements feature improves traffic load balancing between peers by distributing new circuits based on existing loads and the desired ratio.
For each capable peer (peers that have the lowest or equal cost specified), the DLSw+ Load Balancing feature calculates the difference between the desired and the actual ratio of circuits being used on a peer. It detects the path that is underloaded in comparison to the other capable peers and assigns new circuits to that path until the desired ratio is achieved.
Guest
