The IOS supports standard authentication packages for access to the router. These are RADIUS and TACACS+. Each security package requires unique user identification for access to the router. These security packages offer multilevel access to IOS command interface functions.
Each feature set contains a standard offering. However, options are provided to enable the IOS software to meet more specific needs. Each hardware platform has a feature set. For the most part, all the routers share the same feature sets. The sets are broken down into three categories. These are:
- Packaging The ordering of Cisco IOS software has been streamlined into feature sets. Prior to IOS Version 11.2 the IOS software was built based on the router requirements. A second enhancement to the delivery of IOS software is the use of feature packs. Feature packs allow you to order the IOS software images and a Windows 95 utility to load the image on the router.
- Feature Sets
The list of features and feature sets and the platforms supporting them are found in Appendix A.
- Basic: The basic feature set for the platform.
- Plus: The basic feature set plus added features depending on the platform.
- Encryption: 40-bit (Plus 40) or 56-bit (Plus 56) data encryption feature sets with the basic or plus feature set.
IOS Release 11.2 introduces software feature packs. Feature packs offer a means for receiving all materials including software images, loading utilities and manuals on CD-ROMs. Each feature pack contains two CD-ROMs. The software CD-ROM contains:
- Feature Packs
A second CD-ROM is included providing the Cisco IOS software documentation reference library. The remaining documentation provided by the feature pack includes an instruction manual for using the Windows 95 software installer program, release notes for the IOS release included on the software CD-ROM and the software license.
- IOS software images
- AS5200 modem software images
- Windows 95 software installer program
Cisco IOS supports a wide array of networking protocols. Of these protocols, Transmission Control Protocol/Internet Protocol (TCP/IP) is by far the most widely used.
- Features Supported All the features found in the matrices of Appendix A are applicable to each router and access server platform. These features cross a wide range of services and functions to take into account old, current and future network configurations.
Cisco IOS software supports TCP/IP features:
Release 10 and 10.3 of IOS introduced new features to already existing standards that have given Cisco routers the ability to provide higher level of security, greater availability, and increase network scalability. Among these features are:
- IP access lists
- IP Security Option (IPSO)
- IP accounting
- Simple Network Management Protocol (SNMP)
- Serial Line Interface Protocol (SLIP)
- Address Resolution Protocol (ARP)
- Reverse Address Resolution Protocol (RARP)
- Domain Name System (DNS) support
- Internet Common Message Protocol (ICMP)
- Internet Group Management Protocol (IGMP)
- User Datagram Protocol (UDP)
- Trivial File Transfer Protocol (FTP)
With the introduction of release 11 and 11.1 the Cisco IOS software enhances router functionality in the areas of security, performance, and routing services. The major enhancements for these releases are:
- Hot Standby Router Protocol (HSRP) and Multigroup HSRP
- Next Hop Resolution Protocol (NHRP)
- Department of Defense Intelligence Information System Network Security for Information Exchange (DNSIX) extended IPSO
- Type of Service (TOS) queuing
- Cisco Discovery Protocol (CDP)
- Border Gateway Protocol (BGP) Communities
Release 11.2 implements more routing protocol enhancements, IP address translation features and access control list usability. The major features introduced are:
- Route Authentication with Message Digest 5 (MD5) encryption algorithm
- IP Access Control List (ACL) Violation Logging
- Policy based routing
- Weighted fair queuing
- NHRP on IPX
- Fast Install for Static Routers
- Fast Switched GRE
- On Demand Routing (ODR) for stub routers
- OSPF On Demand Circuit (RFC1793)
- OSPF Not-So-Stubby-Area (NSSA)
- BGP4 enhancements
- Soft Configuration
- Prefix filtering with inbound route maps
- Network Address Translation (NAT)
- Named IP access control list
- Integrated routing and bridging (IRB)