Classifying Network Traffic Using NBAR
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Table Of Contents
Classifying Network Traffic Using NBAR
NBAR and Classification of HTTP Traffic
Classification of HTTP Traffic by URL, Host, or MIME
Classification of HTTP Traffic Using the HTTP Header Fields
Combining Classification of HTTP Headers and URL, Host, or MIME Type to Identify HTTP Traffic
NBAR and Classification of Citrix ICA Traffic
Classification of Citrix ICA Traffic by Published Application Name
Classification of Citrix ICA Traffic by ICA Tag Number
NBAR and RTP Payload Type Classification
NBAR and Classification of Custom Protocols and Applications
NBAR and Classification of Peer-to-Peer File-Sharing Applications
NBAR and Classification of Streaming Protocols
Classifying Network Traffic Using NBAR
First Published: April 4, 2006Last Updated: May 7, 2007Network-Based Application Recognition (NBAR) is a classification engine that recognizes and classifies a wide variety of protocols and applications. When NBAR recognizes and classifies a protocol or application, the network can be configured to apply the appropriate quality of service (QoS) for that application or traffic with that protocol.
This module contains overview information about classifying network traffic using NBAR. The processes for configuring NBAR are documented in separate modules.
Note
This module includes information for both NBAR and Distributed Network-Based Application Recognition (dNBAR). dNBAR is NBAR used on the Cisco 7500 router with a Versatile Interface Processor (VIP) and on the Catalyst 6000 family of switches with a FlexWAN module. The implementation of NBAR and dNBAR is identical. Therefore, unless otherwise noted, the term NBAR is used throughout this module to describe both NBAR and dNBAR. The term dNBAR is used only when applicable.
Contents
Prerequisites for Using NBAR
CEF
Before you configure NBAR, you must enable Cisco Express Forwarding (CEF). For more information on CEF, see the Cisco IOS IP Switching Configuration Guide, Release 12.4.
Stateful Switchover Support
NBAR is currently not supported with Stateful Switchover (SSO). This restriction applies to the Catalyst 6500 switches and to the Cisco 7500 and Cisco 7600 series routers.
Memory Requirements for dNBAR
To use dNBAR on a Cisco 7500 series router, you must be using a slot controller (or VIP processor) that has 64 MB of DRAM or more. Therefore, before configuring dNBAR on your Cisco 7500 series router, review the DRAM specifications for your particular slot controller or VIP processor.
Restrictions for Using NBAR
NBAR does not support the following:
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NBAR is not supported on the following logical interfaces:
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Information About Using NBAR
Before classifying network traffic using NBAR, you should understand the following concepts:
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NBAR Functionality
NBAR is a classification engine that recognizes and classifies a wide variety of protocols and applications, including web-based and other difficult-to-classify applications and protocols that use dynamic TCP/UDP port assignments.
When NBAR recognizes and classifies a protocol or application, the network can be configured to apply the appropriate QoS for that application or traffic with that protocol. The QoS is applied using the Modular Quality of Service Command-Line Interface (MQC).
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Examples of the QoS features that can be applied to the network traffic (using the MQC) after NBAR has recognized and classified the application or protocol include the following:
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For Cisco IOS Release 12.2(18)ZY, on the Catalyst 6500 series switch (that is equipped with a Supervisor 32/programmable intelligent services accelerator [PISA] engine), QoS features such as the ones listed below can be configured. These features can be configured (using the MQC) after NBAR has recognized and classified the application or protocol.
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NBAR introduces several classification features that identify applications and protocols from Layer 4 through Layer 7. These classification features include the following:
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This kind of classification requires stateful inspection; that is, the ability to inspect a protocol across multiple packets during packet classification.
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Deep-packet classification is classification performed at a finer level of granularity. For instance, if a packet is already classified as HTTP traffic, it may be further classified by HTTP traffic with a specific URL.
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NBAR includes a Protocol Discovery feature that provides an easy way to discover application protocols that are operating on an interface. For more information about Protocol Discovery, see the "Enabling Protocol Discovery" module.
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NBAR Benefits
Improved Network Management
Identifying and classifying network traffic is an important first step in implementing QoS. A network administrator can more effectively implement QoS in a networking environment after identifying the amount and the variety of applications and protocols that are running on a network.
NBAR gives network administrators the ability to see the variety of protocols and the amount of traffic generated by each protocol. After gathering this information, NBAR allows users to organize traffic into classes. These classes can then be used to provide different levels of service for network traffic, thereby allowing better network management by providing the right level of network resources for network traffic.
NBAR and Classification of HTTP Traffic
This section includes information about the following topics:
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Classification of HTTP Traffic by URL, Host, or MIME
NBAR can classify application traffic by looking beyond the TCP/UDP port numbers of a packet. This is subport classification. NBAR looks into the TCP/UDP payload itself and classifies packets based on content within the payload such as that transaction identifier, message type, or other similar data.
Classification of HTTP traffic by URL, host, or Multipurpose Internet Mail Extension (MIME) type is an example of subport classification. NBAR classifies HTTP traffic by text within the URL or host fields of a request using regular expression matching. HTTP URL matching in NBAR supports most HTTP request methods such as GET, PUT, HEAD, POST, DELETE, and TRACE. The NBAR engine then converts the specified match string into a regular expression.
NBAR recognizes HTTP packets that contain the URL and classifies all packets that are sent to the source of the HTTP request. Figure 1 illustrates a network topology with NBAR in which Router Y is the NBAR-enabled router.
Figure 1 Network Topology with NBAR
When specifying a URL for classification, include only the portion of the URL that follows the www.hostname.domain in the match statement. For example, for the URL www.cisco.com/latest/whatsnew.html, include only /latest/whatsnew.html.
Host specification is identical to URL specification. NBAR performs a regular expression match on the host field contents inside an HTTP packet and classifies all packets from that host. For example, for the URL www.cisco.com/latest/whatsnew.html, include only www.cisco.com.
For MIME type matching, the MIME type can contain any user-specified text string. A list of the Internet Assigned Numbers Authority (IANA)-supported MIME types can be found at the following URL:
ftp://ftp.isi.edu/in-notes/iana/assignments/media-types/media-types
In MIME type matching, NBAR classifies the packet that contains the MIME type and all subsequent packets, which are sent to the source of the HTTP request.
NBAR supports URL and host classification in the presence of persistent HTTP. NBAR does not classify packets that are part of a pipelined request. With pipelined requests, multiple requests are pipelined to the server before previous requests are serviced. Pipelined requests are a less commonly used type of persistent HTTP request.
In Cisco IOS Release 12.3(4)T, the NBAR Extended Inspection for HTTP Traffic feature was introduced. This feature allows NBAR to scan TCP ports that are not well known and to identify HTTP traffic that traverses these ports. HTTP traffic classification is no longer limited to the well-known and defined TCP ports.
Classification of HTTP Traffic Using the HTTP Header Fields
In Cisco IOS Release 12.3(11)T, NBAR introduced expanded ability for users to classify HTTP traffic using information in the HTTP header fields.
HTTP works using a client/server model. HTTP clients open connections by sending a request message to an HTTP server. The HTTP server then returns a response message to the HTTP client (this response message is typically the resource requested in the request message from the HTTP client). After delivering the response, the HTTP server closes the connection and the transaction is complete.
HTTP header fields are used to provide information about HTTP request and response messages. HTTP has numerous header fields. For additional information on HTTP headers, see section 14 of RFC 2616: Hypertext Transfer Protocol—HTTP/1.1. This RFC can be found at the following URL:
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
NBAR is able to classify the following HTTP header fields:
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Within NBAR, the match protocol http c-header-field command is used to specify that NBAR identify request messages (the "c" in the c-header-field portion of the command is for client). The match protocol http s-header-field command is used to specify response messages (the "s" in the s-header-field portion of the command is for server).
Examples
In the following example, any request message that contains "somebody@cisco.com" in the User-Agent, Referer, or From fields will be classified by NBAR. Typically, a term with a format similar to "somebody@cisco.com" would be found in the From header field of the HTTP request message.
match protocol http c-header-field "somebody@cisco.com"In the following example, any request message that contains "http://www.cisco.com/routers" in the User-Agent, Referer, or From fields will be classified by NBAR. Typically, a term with a format similar to "http://www.cisco.com/routers" would be found in the Referer header field of the HTTP request message.
match protocol http c-header-field "http://www.cisco.com/routers"In the following example, any request message that contains "CERN-LineMode/2.15" in the User-Agent, Referer, or From header fields will be classified by NBAR. Typically, a term with a format similar to "CERN-LineMode/2.15" would be found in the User-Agent header field of the HTTP request message.
match protocol http c-header-field "CERN-LineMode/2.15"In the following example, any response message that contains "CERN/3.0" in the Content-Base, Content-Encoding, Location, or Server header fields will be classified by NBAR. Typically, a term with a format similar to "CERN/3.0" would be found in the Server header field of the response message.
match protocol http s-header-field "CERN/3.0"In the following example, any response message that contains "http://www.cisco.com/routers" in the Content-Base, Content-Encoding, Location, or Server header fields will be classified by NBAR. Typically, a term with a format similar to "http://www.cisco.com/routers" would be found in the Content-Base or Location header field of the response message.
match protocol http s-header-field "http://www.cisco.com/routers"In the following example, any response message that contains "gzip" in the Content-Base, Content-Encoding, Location, or Server header fields will be classified by NBAR. Typically, the term "gzip" would be found in the Content-Encoding header field of the response message.
match protocol http s-header-field "gzip"Combining Classification of HTTP Headers and URL, Host, or MIME Type to Identify HTTP Traffic
Note that combinations of URL, Host, MIME type, and HTTP headers can be used during NBAR configuration. These combinations provide customers with more flexibility to classify specific HTTP traffic based on their network requirements.
Examples
In the following example, HTTP header fields are combined with a URL to classify traffic. In this example, traffic with a User-Agent field of "CERN-LineMode/3.0" and a Server field of "CERN/3.0", along with URL "www.cisco.com," will be classified using NBAR:
class-map match-all c-http match protocol http c-header-field "CERN-LineMode/3.0" match protocol http s-header-field "CERN/3.0" match protocol http url "www.cisco.com"NBAR and Classification of Citrix ICA Traffic
NBAR can classify Citrix Independent Computing Architecture (ICA) traffic and perform subport classification of Citrix traffic based on the published application name or ICA tag number.
This section includes information about the following topics:
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Classification of Citrix ICA Traffic by Published Application Name
NBAR can monitor Citrix ICA client requests for a published application destined to a Citrix ICA Master browser. After the client requests the published application, the Citrix ICA Master browser directs the client to the server with the most available memory. The Citrix ICA client then connects to this Citrix ICA server for the application.
Note
In Server Browser Mode, NBAR statefully tracks and monitors traffic and performs a regular expression search on the packet contents for the published application name specified by the match protocol citrix command. The published application name is specified by using the app keyword and the application-name-string argument of the match protocol citrix command. For more information about the match protocol citrix command, see the Cisco IOS Quality of Service Solutions Command Reference, Release 12.4T.
The Citrix ICA session triggered to carry the specified application is cached, and traffic is classified appropriately for the published application name.
Citrix ICA Client Modes
Citrix ICA clients can be configured in various modes. NBAR cannot distinguish among Citrix applications in all modes of operation. Therefore, network administrators might need to collaborate with Citrix administrators to ensure that NBAR properly classifies Citrix traffic.
A Citrix administrator can configure Citrix to publish Citrix applications individually or as the entire desktop. In the Published Desktop mode of operation, all applications within the published desktop of a client use the same TCP session. Therefore, differentiation among applications is impossible, and NBAR can be used to classify Citrix applications only as aggregates (by looking at port 1494).
The Published Application mode for Citrix ICA clients is recommended when you use NBAR. In Published Application mode, a Citrix administrator can configure a Citrix client in either seamless or non-seamless (windows) modes of operation. In nonseamless mode, each Citrix application uses a separate TCP connection, and NBAR can be used to provide interapplication differentiation based on the name of the published application.
Seamless mode clients can operate in one of two submodes: session sharing or nonsession sharing. In seamless session sharing mode, all clients share the same TCP connection, and NBAR cannot differentiate among applications. Seamless sharing mode is enabled by default on some software releases. In seamless nonsession sharing mode, each application for each particular client uses a separate TCP connection. NBAR can provide interapplication differentiation in seamless nonsession sharing mode.
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Classification of Citrix ICA Traffic by ICA Tag Number
Citrix uses one TCP session each time an application is opened. In the TCP session, a variety of Citrix traffic may be intermingled in the same session. For example, print traffic may be intermingled with interactive traffic, causing interruption and delay for a particular application. Most people would prefer that printing be handled as a background process and that printing not interfere with the processing of higher-priority traffic.
To accommodate this preference, the Citrix ICA protocol includes the ability to identify Citrix ICA traffic based on the ICA tag number of the packet. The ability to identify, tag, and prioritize Citrix ICA traffic is referred to as ICA Priority Packet Tagging. With ICA Priority Packet Tagging, Citrix ICA traffic is categorized as high, medium, low, and background, depending on the ICA tag of the packet.
When ICA traffic priority tag numbers are used, and the priority of the traffic is determined, QoS features can be implemented to determine how the traffic will be handled. For example, QoS traffic policing can be configured to transmit or drop packets with a specific priority.
Citrix ICA Packet Tagging
The Citrix ICA tag is included in the first two bytes of the Citrix ICA packet, after the initial negotiations are completed between Citrix client and server. These bytes are not compressed or encrypted.
The first two bytes of the packet (byte 1 and byte 2) contain the byte count and the ICA priority tag number. Byte 1 contains the low-order byte count, and the first two bits of byte 2 contain the priority tags. The other six bits contain the high-order byte count.
The ICA priority tag value can be a number from 0 to 3. The number indicates the packet priority, with 0 being the highest priority and 3 being the lowest priority.
To prioritize Citrix traffic by the ICA tag number of the packet, you specify the tag number using the ica-tag keyword and the ica-tag-value argument of the match protocol citrix command. For more information about the match protocol citrix command, see the Cisco IOS Quality of Service Solutions Command Reference, Release 12.4T.
NBAR and RTP Payload Type Classification
RTP is a packet format for multimedia data streams. It can be used for media-on-demand as well as for interactive services such as Internet telephony. RTP consists of a data and a control part. The control part is called Real-Time Transport Control Protocol (RTCP). RTCP is a separate protocol that is supported by NBAR. It is important to note that the NBAR RTP Payload Type Classification feature does not identify RTCP packets and that RTCP packets run on odd-numbered ports while RTP packets run on even-numbered ports.
The data part of RTP is a thin protocol that provides support for applications with real-time properties such as continuous media (audio and video), which includes timing reconstruction, loss detection, and security and content identification. RTP is discussed in RFC 1889 (A Transport Protocol for Real-Time Applications) and RFC 1890 (RTP Profile for Audio and Video Conferences with Minimal Control).
The RTP payload type is the data transported by RTP in a packet, for example audio samples or compressed video data.
NBAR RTP Payload Type Classification not only allows one to statefully identify real-time audio and video traffic but can also differentiate on the basis of audio and video codecs to provide more granular QoS. The RTP Payload Type Classification feature, therefore, looks deep into the RTP header to classify RTP packets. NBAR RTP Payload Type Classification was first introduced in Cisco IOS Release 12.2(8)T and is also available in Cisco IOS Release 12.1(11b)E.
NBAR and Classification of Custom Protocols and Applications
NBAR supports the use of custom protocols to identify custom applications. Custom protocols support static port-based protocols and applications that NBAR does not currently support. You can add to the set of protocols and application types that NBAR recognizes by creating custom protocols.
Custom protocols extend the capability of NBAR Protocol Discovery to classify and monitor additional static port applications and allows NBAR to classify nonsupported static port traffic.
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NBAR and Classification of Peer-to-Peer File-Sharing Applications
The following are the most common peer-to-peer file-sharing applications supported by NBAR:
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Gnutella Also Supported
Gnutella is another file-sharing protocol that became classifiable using NBAR in Cisco IOS Release 12.1(12c)E.
Applications that use the Gnutella protocol include Bearshare, Gnewtellium, Gnucleus, Gtk-Gnutella, Limewire, Mutella, Phex, Qtella, Swapper, and Xolo.
The match protocol gnutella file-transfer regular-expression and match protocol fasttrack file-transfer regular-expression commands are used to enable Gnutella and FastTrack classification in a traffic class. The regular-expression variable can be expressed as "*" to indicate that all FastTrack or Gnutella traffic be classified by a traffic class.
In the following example, all FastTrack traffic is classified into class map nbar:
class-map match-all nbar match protocol fasttrack file-transfer "*"Similarly, all Gnutella traffic is classified into class map nbar in the following example:
class-map match-all nbar match protocol gnutella file-transfer "*"Wildcard characters in a regular expression can also be used to identify specified Gnutella and FastTrack traffic. These regular expression matches can be used to match on the basis of filename extension or a particular string in a filename.
In the following example, all Gnutella files that have the .mpeg extension will be classified into class map nbar.
class-map match-all nbar match protocol gnutella file-transfer "*.mpeg"In the following example, only Gnutella traffic that contains the characters "cisco" is classified:
class-map match-all nbar match protocol gnutella file-transfer "*cisco*"The same examples can be used for FastTrack traffic:
class-map match-all nbar match protocol fasttrack file-transfer "*.mpeg"or
class-map match-all nbar match protocol fasttrack file-transfer "*cisco*"NBAR and Classification of Streaming Protocols
In Cisco IOS Release 12.3(7)T, NBAR introduced support for Real Time Streaming Protocol (RTSP). RTSP is the protocol used for applications with steaming audio, such as the following:
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NBAR and AutoQoS
Earlier Cisco IOS releases included two features that allow you to automate the deployment of QoS on your network: AutoQoS—Voice over IP (VoIP); and AutoQoS for the Enterprise. Both of these AutoQoS features take advantage of the traffic classification functionality of NBAR.
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AutoQoS—VoIP
This feature was available with Cisco IOS Release 12.2(15)T. The AutoQoS—VoIP feature allows you to automate the deployment of QoS on your network and provides a means for simplifying the implementation and provisioning of QoS for VoIP traffic. For more information about the AutoQoS—VoIP feature and how it uses NBAR, see the AutoQoS—VoIP feature module, Release 12.2(15)T.
AutoQoS for the Enterprise
This feature was available with Cisco IOS Release 12.3(11)T. The AutoQoS for the Enterprise feature allows you to automate the deployment of QoS in a general business environment, particularly for midsize companies and branch offices of larger companies. It expands on the functionality available with the AutoQoS—VoIP feature. For more information about the AutoQoS for the Enterprise feature and how it uses NBAR, see the AutoQoS for the Enterprise feature module, Release 12.3(11)T.
NBAR-Supported Protocols
Table 1 lists the NBAR-supported protocols available in Cisco IOS software, sorted by category. The table also provides information about the protocol type, the well-known port numbers, the syntax for entering the protocol in NBAR, and the Cisco IOS release in which the protocol was initially supported.
Many peer-to-peer file-sharing applications not listed in this table can be classified using FastTrack or Gnutella. See the "NBAR and Classification of Peer-to-Peer File-Sharing Applications" section for additional information.
RTSP can be used to classify various types of applications that use streaming audio. See the "NBAR and Classification of Streaming Protocols" section for additional information.
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Table 1 NBAR-Supported Protocols
Enterprise Application
Citrix ICA
TCP/
UDPDynamically Assigned
Citrix ICA traffic by application name
citrix
citrix app12.1(2)E
12.1(5)TPCAnywhere
TCP
5631, 65301
Symantic pcAnywhere
pcanywhere
12.0(5)XE2
12.1(1)E
12.1(5)TPCAnywhere
UDP
22, 5632
Symantic pcAnywhere
pcanywhere
12.0(5)XE2
12.1(1)E
12.1(5)TNovadigm
TCP/ UDP
3460-3465
Novadigm Enterprise Desktop Manager (EDM)
novadigm
12.1(2)E
12.1(5)TSAP
TCP
3300-3315 (sap-pgm. pdlm)
3200-3215 (sap-app. pdlm)
3600-3615 (sap-msg. pdlm)Application server to application server traffic (sap-pgm.pdlm)
Client to application server traffic (sap-app.pdlm)
Client to message server traffic (sap-msg.pdlm)
sap
12.3
12.3T
12.2T
12.1ERouting Protocol
BGP
TCP/ UDP
179
Border Gateway Protocol
bgp
12.0(5)XE2
12.1(1)E
12.1(5)TEGP
IP
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Exterior Gateway Protocol
egp
12.0(5)XE2
12.1(1)E
12.1(5)TEIGRP
IP
88
Enhanced Interior Gateway Routing Protocol
eigrp
12.0(5)XE2
12.1(1)E
12.1(5)TOSPF
TCP
Dynamically Assigned
Open Shortest Path First
ospf
12.3(8)T
RIP
UDP
520
Routing Information Protocol
rip
12.0(5)XE2
12.1(1)E
12.1(5)TDatabase
SQL*NET
TCP/ UDP
Dynamically Assigned
SQL*NET for Oracle
sqlnet
12.0(5)XE2
12.1(1)E
12.1(5)TMS- SQLServer
TCP
1433
Microsoft SQL Server Desktop Videocon-
ferencingsqlserver
12.0(5)XE2
12.1(1)E
12.1(5)TSecurity and Tunneling
GRE
IP
47
Generic Routing Encapsulation
gre
12.0(5)XE2
12.1(1)E
12.1(5)TIPINIP
IP
4
IP in IP
ipinip
12.0(5)XE2
12.1(1)E
12.1(5)TIPsec
IP
50, 51
IP Encapsulating Security Payload/
Authentication-
Headeripsec
12.0(5)XE2
12.1(1)E
12.1(5)TL2TP
UDP
1701
L2F/L2TP Tunnel
l2tp
12.0(5)XE2
12.1(1)E
12.1(5)TMS-PPTP
TCP
1723
Microsoft Point-to-Point Tunneling Protocol for VPN
pptp
12.0(5)XE2
12.1(1)E
12.1(5)TSFTP
TCP
990
Secure FTP
secure-ftp
12.0(5)XE2
12.1(1)E
12.1(5)TSHTTP
TCP
443
Secure HTTP
secure-http
12.0(5)XE2
12.1(1)E
12.1(5)TSIMAP
TCP/
UDP585, 993
Secure IMAP
secure-imap
12.0(5)XE2
12.1(1)E
12.1(5)TSIRC
TCP/
UDP994
Secure IRC
secure-irc
12.0(5)XE2
12.1(1)E
12.1(5)TSLDAP
TCP/
UDP636
Secure LDAP
secure-ldap
12.0(5)XE2
12.1(1)E
12.1(5)TSNNTP
TCP/
UDP563
Secure NNTP
secure-nntp
12.0(5)XE2
12.1(1)E
12.1(5)TSPOP3
TCP/
UDP995
Secure POP3
secure-pop3
12.0(5)XE2
12.1(1)E
12.1(5)TSTELNET
TCP
992
Secure Telnet
secure-telnet
12.0(5)XE2
12.1(1)E
12.1(5)TSecurity and Tunneling (continued)
SOCKS
TCP
1080
Firewall Security Protocol
socks
12.0(5)XE2
12.1(1)E
12.1(5)TSSH
TCP
22
Secured Shell
ssh
12.0(5)XE2
12.1(1)E
12.1(5)TNetwork Management
ICMP
IP
1
Internet Control Message Protocol
icmp
12.0(5)XE2
12.1(1)E
12.1(5)TSNMP
TCP/
UDP161, 162
Simple Network Management Protocol
snmp
12.0(5)XE2
12.1(1)E
12.1(5)TSyslog
UDP
514
System Logging Utility
syslog
12.0(5)XE2
12.1(1)E
12.1(5)TNetwork Mail Services
IMAP
TCP/
UDP143, 220
Internet Message Access Protocol
imap
12.0(5)XE2
12.1(1)E
12.1(5)TPOP3
TCP/
UDP110
Post Office Protocol
pop3
12.0(5)XE2
12.1(1)E
12.1(5)TExchange
TCP
135
MS-RPC for Exchange
exchange
12.0(5)XE2
12.1(1)E
12.1(5)TNotes
TCP/
UDP1352
Lotus Notes
notes
12.0(5)XE2
12.1(1)E
12.1(5)TSMTP
TCP
25
Simple Mail Transfer Protocol
smtp
12.0(5)XE2
12.1(1)E
12.1(5)TDirectory
DHCP/
BOOTPUDP
67, 68
Dynamic Host Configuration Protocol/ Bootstrap Protocol
dhcp
12.0(5)XE2
12.1(1)E
12.1(5)TFinger
TCP
79
Finger User Information Protocol
finger
12.0(5)XE2
12.1(1)E
12.1(5)TDNS
TCP/
UDP53
Domain Name System
dns
12.0(5)XE2
12.1(1)E
12.1(5)TKerberos
TCP/
UDP88, 749
Kerberos Network Authentication Service
kerberos
12.0(5)XE2
12.1(1)E
12.1(5)TLDAP
TCP/
UDP389
Lightweight Directory Access Protocol
ldap
12.0(5)XE2
12.1(1)E
12.1(5)TStreaming Media
CU-SeeMe
TCP/
UDP7648, 7649
Desktop Video Conferencing
cuseeme
12.0(5)XE2
12.1(1)E
12.1(5)TCU-SeeMe
UDP
24032
Desktop Video Conferencing
cuseeme
12.0(5)XE2
12.1(1)E
12.1(5)TNetshow
TCP/ UDP
Dynamically Assigned
Microsoft Netshow
netshow
12.0(5)XE2
12.1(1)E
12.1(5)TRealAudio
TCP/ UDP
Dynamically Assigned
RealAudio Streaming Protocol
realaudio
12.0(5)XE2
12.1(1)E
12.1(5)TStreamWorks
UDP
Dynamically Assigned
Xing Technology Stream Works Audio and Video
streamwork
12.0(5)XE2
12.1(1)E
12.1(5)TVDOLive
TCP/ UDP
Dynamically Assigned
VDOLive Streaming Video
vdolive
12.0(5)XE2
12.1(1)E
12.1(5)TStreaming Media/ Multimedia
RTSP
TCP/ UDP
Dynamically Assigned
Real Time Streaming Protocol
rtsp
12.3(11)T
MGCP
TCP/ UDP
2427, 2428, 2727
Media Gateway Control Protocol
mgcp
12.3(7)T
Internet
FTP
TCP
Dynamically Assigned
File Transfer Protocol
ftp
12.0(5)XE2
12.1(1)E
12.1(5)TGopher
TCP/ UDP
70
Internet Gopher Protocol
gopher
12.0(5)XE2
12.1(1)E
12.1(5)THTTP
TCP
802
Hypertext Transfer Protocol
http
12.0(5)XE2
12.1(1)E
12.1(5)TIRC
TCP/ UDP
194
Internet Relay Chat
irc
12.0(5)XE2
12.1(1)E
12.1(5)TTelnet
TCP
23
Telnet Protocol
telnet
12.0(5)XE2
12.1(1)E
12.1(5)TTFTP
UDP
Dynamically Assigned
Trivial File Transfer Protocol
tftp
12.0(5)XE2
12.1(1)E
12.1(5)TNNTP
TCP/ UDP
119
Network News Transfer Protocol
nntp
12.0(5)XE2
12.1(1)E
12.1(5)TSignaling
RSVP
UDP
1698, 1699
Resource Reservation Protocol
rsvp
12.0(5)XE2
12.1(1)E
12.1(5)TRPC
NFS
TCP/ UDP
2049
Network File System
nfs
12.0(5)XE2
12.1(1)E
12.1(5)TSunrpc
TCP/ UDP
Dynamically Assigned
Sun Remote Procedure Call
sunrpc
12.0(5)XE2
12.1(1)E
12.1(5)TNon-IP and LAN/
LegacyNetBIOS
TCP/ UDP
137, 138, 139
NetBIOS over IP (MS Windows)
netbios
12.0(5)XE2
12.1(1)E
12.1(5)TMisc.
NTP
TCP/ UDP
123
Network Time Protocol
ntp
12.0(5)XE2
12.1(1)E
12.1(5)TPrinter
TCP/ UDP
515
Printer
printer
12.1(2)E
12.1(5)TX Windows
TCP
6000-6003
X11, X Windows
xwindows
12.0(5)XE2
12.1(1)E
12.1(5)Tr-commands
TCP
Dynamically Assigned
rsh, rlogin, rexec
rcmd
12.0(5)XE2
12.1(1)E
12.1(5)TVoice
H.323
TCP
Dynamically Assigned
H.323 Teleconferencing Protocol
h323
12.3(7)T
RTCP
TCP/ UDP
Dynamically Assigned
Real-Time Control Protocol
rtcp
12.1E
12.2T
12.3
12.3T
12.3(7)TRTP
TCP/ UDP
Dynamically Assigned
Real-Time Transport Protocol Payload Classification
rtp
12.2(8)T
SIP
TCP/UPD
5060
Session Initiation Protocol
sip
12.3(7)T
SCCP/ Skinny
TCP
2000, 2001, 2002
Skinny Client Control Protocol
skinny
12.3(7)T
Skype3
TCP/UDP
Dynamically Assigned
Peer-to-Peer VoIP Client Software
Note
skype
12.4(4)T
Peer-to-Peer File-Sharing Applications
BitTorrent
TCP
Dynamically Assigned, or
6881-6889BitTorrent File Transfer Traffic
bittorrent
12.4(2)T
Direct Connect
TCP/ UDP
411
Direct Connect File Transfer Traffic
directconnect
12.4(4)T
eDonkey/ eMule
TCP
4662
eDonkey File- Sharing Application
eMule traffic is also classified as eDonkey traffic in NBAR.
edonkey
12.3(11)T
FastTrack
N/A
Dynamically Assigned
FastTrack
fasttrack
12.1(12c)E
Gnutella
TCP
Dynamically Assigned
Gnutella
gnutella
12.1(12c)E
KaZaA
TCP/ UPD
Dynamically Assigned
KaZaA
Note that earlier KaZaA version 1 traffic can be classified using FastTrack.
kazaa2
12.2(8)T
WinMX
TCP
6699
WinMX Traffic
winmx
12.3(7)T
1 Indicates the Cisco IOS maintenance release that first supported the protocol. This table is updated when a protocol is added to a new Cisco IOS release train.
2 In Release 12.3(4)T, the NBAR Extended Inspection for Hypertext Transfer Protocol (HTTP) Traffic feature was introduced. This feature allows NBAR to scan TCP ports that are not well known and identify HTTP traffic traversing these ports.
3 Skype was introduced in Cisco IOS Release 12.4(4)T. As a result of this introduction, Skype is now native in (included with) the Cisco IOS software and uses the NBAR infrastructure new to Cisco IOS Release 12.4(4)T.
NBAR Memory Management
NBAR uses approximately 150 bytes of DRAM for each traffic flow that requires stateful inspection. (See Table 1 for a list of protocols supported by NBAR that require stateful inspection.) When NBAR is configured, it allocates 1 MB of DRAM to support up to 5000 concurrent traffic flows. NBAR checks to see if more memory is required to handle additional concurrent stateful traffic flows. If such a need is detected, NBAR expands its memory usage in increments of 200 Kb to 400 Kb.
NBAR Protocol Discovery
NBAR includes a feature called Protocol Discovery. Protocol Discovery provides an easy way to discover the application protocols that are operating on an interface. For more information about Protocol Discovery, see the "Enabling Protocol Discovery" module.
NBAR Protocol Discovery MIB
The NBAR Protocol Discovery Management Information Base (MIB) expands the capabilities of NBAR Protocol Discovery by providing the following new functionality through Simple Network Management Protocol (SNMP):
•
•
•
•
For more information about the NBAR Protocol Discovery MIB, see the Network-Based Application Recognition Protocol Discovery Management Information Base feature module, Release 12.2(15)T.
NBAR Configuration Processes
Configuring NBAR consists of the following processes:
•
When you configure NBAR, the first process is to enable Protocol Discovery.
•
After you enable Protocol Discovery, the next process is to configure NBAR using the functionality of the MQC.
•
Adding PDLMs extends the functionality of NBAR by enabling NBAR to recognize additional protocols on your network.
•
Custom protocols extend the capability of NBAR Protocol Discovery to classify and monitor additional static port applications and allow NBAR to classify nonsupported static port traffic.
Where to Go Next
Begin configuring NBAR by first enabling Protocol Discovery. To enable Protocol Discovery, see the "Enabling Protocol Discovery" module.
Additional References
The following sections provide references related to classifying network traffic using NBAR.
Related Documents
QoS commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples
Cisco IOS Quality of Service Solutions Command Reference, Release 12.4T
QoS features and functionality
Cisco IOS Quality of Service Solutions Configuration Guide, Release 12.4
QoS features and functionality on the Catalyst 6500 series switch
"Configuring PFC QoS" chapter of the Catalyst Supervisor Engine 32 PISA Cisco IOS Software Configuration Guide, Release 12.2 ZY
Classifying network traffic if not using NBAR
"Classifying Network Traffic" module of the Cisco IOS Quality of Service Solutions Configuration Guide, Release 12.4
Marking network traffic
"Marking Network Traffic" module of the Cisco IOS Quality of Service Solutions Configuration Guide, Release 12.4
CISCO-NBAR-PROTOCOL-DISCOVERY MIB"
Network-Based Application Recognition Management Information Base feature module, Release 12.2(15)T
CEF
Cisco IOS IP Switching Configuration Guide, Release 12.4
AutoQoS1 and VoIP traffic
AutoQoS for the Enterprise*
AutoQoS for the Enterprise feature module, Release 12.3(11)T
NBAR Protocol Discovery MIB
Network-Based Application Recognition Protocol Discovery Management Information Base feature module, Release 12.2(15)T
Enabling Protocol Discovery
Configuring NBAR using the MQC
Adding application recognition modules (also known as PDLMs)
Creating a custom protocol
"Creating a Custom Protocol" module
1 Cisco IOS Release 12.2(18)ZY does not support either the AutoQoS—Voice over IP (VoIP) feature or the AutoQoS for the Enterprise feature on the Catalyst 6500 series switch.
Standards
MIBs
CISCO-NBAR-PROTOCOL-DISCOVERY MIB
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
RFCs
Technical Assistance
Glossary
encryption—Encryption is the application of a specific algorithm to data so as to alter the appearance of the data, making it incomprehensible to those who are not authorized to see the information.
HTTP—Hypertext Transfer Protocol. The protocol used by web browsers and web servers to transfer files, such as text and graphic files.
IANA—Internet Assigned Numbers Authority. An organization operated under the auspices of the Internet Society (ISOC) as a part of the Internet Architecture Board (IAB). IANA delegates authority for IP address-space allocation and domain-name assignment to the InterNIC and other organizations. IANA also maintains a database of assigned protocol identifiers used in the TCP/IP stack, including autonomous system numbers.
LAN—local-area network. A high-speed, low-error data network that covers a relatively small geographic area (up to a few thousand meters). LANs connect workstations, peripherals, terminals, and other devices in a single building or other geographically limited area. LAN standards specify cabling and signaling at the physical and data link layers of the Open System Interconnection (OSI) model. Ethernet, FDDI, and Token Ring are widely used LAN technologies.
MIME—Multipurpose Internet Mail Extension. The standard for transmitting nontext data (or data that cannot be represented in plain ASCII code) in Internet mail, such as binary, foreign language text (such as Russian or Chinese), audio, and video data. MIME is defined in RFC 2045: Multipurpose Internet Mail Extension (MIME) Part One: Format of Internet Message Bodies.
MPLS—Multiprotocol Label Switching. A switching method that forwards IP traffic using a label. This label instructs the routers and the switches in the network where to forward the packets based on preestablished IP routing information.
MQC—Modular Quality of Service Command-Line Interface. A command-line interface that allows you to define traffic classes, create and configure traffic policies (policy maps), and then attach the policy maps to interfaces. The policy maps are used to apply the appropriate quality of service (QoS) to network traffic.
PDLM—Packet Description Language Module. A file that contains Packet Description Language statements used to define the signature of one or more application protocols.
Protocol Discovery—A feature included with NBAR. Protocol Discovery provides a way to discover the application protocols that are operating on an interface.
QoS—quality of service. A measure of performance for a transmission system that reflects its transmission quality and service availability.
RTCP—RTP Control Protocol. A protocol that monitors the QoS of an IPv6 Real-Time Transport Protocol (RTP) connection and conveys information about the ongoing session.
RTSP—Real Time Streaming Protocol. A means for enabling the controlled delivery of real-time data, such as audio and video. Sources of data can include both live data feeds, such as live audio and video, and stored content, such as prerecorded events. RTSP is designed to work with established protocols, such as Real-Time Transport Protocol (RTP) and HTTP.
stateful protocol—A protocol that uses TCP and UDP port numbers that are determined at connection time.
static protocol—A protocol that uses well-defined (predetermined) TCP and UDP ports for communication.
subport classification—The classification of network traffic by information that is contained in the packet payload; that is, information found beyond the TCP or UDP port number.
TCP—Transmission Control Protocol. A connection-oriented transport layer protocol that provides reliable full-duplex data transmission. TCP is part of the TCP/IP protocol stack.
tunneling—Tunneling is an architecture that is designed to provide the services necessary to implement any standard point-to-point encapsulation scheme.
UDP—User Datagram Protocol. A connectionless transport layer protocol in the TCP /IP protocol stack. UDP is a simple protocol that exchanges datagrams without acknowledgments or guaranteed delivery, requiring that error processing and retransmission be handled by other protocols. UDP is defined in RFC 768: User Datagram Protocol.
WAN—wide-area network. A data communications network that serves users across a broad geographic area and often uses transmission devices provided by common carriers.
Note
Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.
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