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Table Of Contents
Annex G (X.25 over Frame Relay)
Annex G (X.25 over Frame Relay)
Feature Summary
The use of X.25 as a network backbone is becoming obsolete as modern networks change their backbones to newer technologies such as Frame Relay, ATM, and IP.
Annex G (X.25 over Frame Relay) facilitates the migration from an X.25 backbone to a Frame Relay backbone by permitting encapsulation of ITU-T X.25/X.75 traffic within a Frame Relay connection. Annex G has developed to accommodate the many Cisco customers in Europe, where IP is not so common, and X.25 continues to be 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 process is largely achieved using X.25 profiles, which were created to streamline X.25 and LAPB configuration. X.25 profiles can contain existing X.25 and LAPB commands and, once created and named, can be simultaneously associated with more than one DLCI connection, using just the profile name.
X.25 Layers 2 and 3 are transparently supported over Annex G. LAPB treats the Frame Relay network like an X.25 network link and passes all of the data and control messages over the Frame Relay network.
Benefits
Annex G provides the following benefits:
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Transparent support of X.25 encapsulation over the Frame Relay network.
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List of Terms
data communications equipment (DCE)—A network device or connection that comprises the network end of the user-to-network interface.
data-link connection identifier (DLCI)—Value that specifies a PVC or SVC in a Frame Relay network.
data terminal equipment (DTE)—A network device or connection that comprises the user end of the user-to-network interface.
data exchange equipment (DXE)—A network device or connection that allows dynamic cooperation with another station to act as a DTE or a DCE (whichever is required for connectivity).
Link Access Protocol, Balanced (LAPB)—Data link layer protocol in X.25.
permanent virtual circuit (PVC)—A permanently established logical association between two physically separate DTEs.
switched virtual circuit (SVC)—A virtual circuit that is dynamically established on demand and torn down when transmission is complete.
virtual circuit (VC)—A logical association between two physically separate DTEs.
Restrictions
The following restrictions apply to Annex G:
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Platforms
This feature is supported on these platforms:
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Prerequisites
Before enabling Annex G connections you must establish a Frame Relay connection. See the sections "Configuration Tasks" and "Configuration Examples" for further details. For more information about configuring Frame Relay, refer to the chapter "Configuring Frame Relay" in the Wide-Area Networking Configuration Guide for Cisco IOS Release 12.0.
Supported MIBs and RFCs
None.
Configuration Tasks
To configure an Annex G connection (assuming you have already configured a Frame Relay connection on your router), use the following commands beginning in global configuration mode:
Configuration Examples
The following example configures X.25 profile "NetworkNodeA" (using the X.25 commands x25 htc, x25 idle, x25 accept-reverse and x25 modulo) on DLCI interfaces 20 and 30; and X.25 profile "NetworkNodeB" (using the X.25 command x25 address) on DLCI interface 40; all on serial interface 1. The example shows the final step of assigning your X.25 profile to the DLCI interface by using the frame-relay interface-dlci command, and then assigning X.25 routes to DLCIs 20, 30, and 40 using the x25 route command. This example assumes you already have Frame Relay enabled on your router.
Router(config)# x25 routingRouter(config)# x25 profile NetworkNodeA dceRouter(config-x25)# x25 htc 128Router(config-x25)# x25 idle 5Router(config-x25)# x25 accept-reverseRouter(config-x25)# x25 modulo 128Router(config-x25)# endRouter(config)# x25 profile NetworkNodeB dceRouter(config-x25)# x25 address 1111Router(config-x25)# endRouter(config)# interface serial1Router(config-if)# encapsulation frame-relayRouter(config-if)# frame-relay interface-dlci 20Router(config-fr-dlci)# x25-profile NetworkNodeARouter(config-fr-dlci)# endRouter(config)# interface serial1Router(config-if)# frame-relay interface-dlci 30Router(config-fr-dlci)# x25-profile NetworkNodeARouter(config-fr-dlci)# endRouter(config)# interface serial1Router(config-if)# frame-relay interface-dlci 40Router(config-fr-dlci)# x25-profile NetworkNodeBRouter(config-fr-dlci)# endRouter(config)# x25 route 2000 interface serial1 dlci 20Router(config)# x25 route 3000 interface serial1 dlci 30Router(config)# x25 route 4000 interface serial1 dlci 40Command Reference
This section documents new or modified commands used to configure the Annex G (X.25 over Frame Relay) feature. All other commands used with this feature are documented in the Cisco 12.0 Command References.
clear x25
Use the clear x25 privileged EXEC command to restart an X.25 or CMNS service, to clear an SVC, or to reset a PVC.
clear x25 {serial number | {ethernet | fastethernet | tokenring | fddi} number mac-address} [vc-number] | [dlci number]
Syntax Description
Command Mode
Privileged EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3. (This command replaces the clear x25-vc command, which first appeared in Cisco IOS Release 8.3.)
This command form is used to disrupt service forcibly on an individual circuit or on all circuits using a specific X.25 service or CMNS service.
If this command is used without the vc-number value, a restart event is initiated, which implicitly clears all SVCs and resets all PVCs.
This command allows the option of restarting an Annex G connection per DLCI number, clearing all X.25 connections, or clearing a specific X.25 logical circuit number on that Annex G link.
Examples
The following example clears the SVC or resets the PVC specified:
clear x25 serial 0 1The following example forces an X.25 restart, which implicitly clears all SVCs and resets all PVCs using the interface:
clear x25 serial 0The following example restarts the specified CMNS service (if active), which implicitly clears all SVCs using the service:
clear x25 ethernet 0 0001.0002.0003The following example clears the specified DLCI Annex G connection (40) from the specified interface:
clear x25 serial 1 40Related Commands
You can use the master indexes or search online to find documentation of related commands.
clear xot
show x25 services
show x25 vc
frame-relay interface-dlci
To assign a data link connection identifier (DLCI) to a specified Frame Relay subinterface on the router or access server, use the frame-relay interface-dlci interface configuration command. To remove this assignment, use the no form of this command.
For Annex G, use the Frame Relay DLCI interface configuration command x-25 profile to configure your X.25 profile to a DLCI connection. To remove this assignment, use the no form of this command.
frame-relay interface-dlci number [ietf | cisco] [voice-encap size]
no frame-relay interface-dlci number [ietf | cisco] [voice-encap size]
frame-relay interface-dlci number [protocol ip ip-address] (for a BOOTP server only)Syntax Description
Command Mode
Interface configuration.
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
By issuing the frame-relay interface-dlci interface configuration command, you enter Frame Relay DLCI interface configuration mode (see the first example below). This gives you the following command options, which must be used with the relevant class or X.25-profile names you previously assigned:
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A Frame Relay DLCI configured for Annex G can be thought of as a single logical X.25/LAPB interface. Therefore, any number of X.25 routes may be configured to route X.25 calls to that logical interface.
The frame-relay interface-dlci command is typically used for subinterfaces; however, it can also be used on main interfaces. Using the frame-relay interface-dlci command on main interfaces will enable the use of routing protocols on interfaces that use inverse ARP. The frame-relay interface-dlci command on a main interface is also valuable for assigning a specific class to a single PVC where special characteristics are desired. Subinterfaces are logical interfaces associated with a physical interface. You must specify the interface and subinterface before you can use this command to assign any DLCIs and any encapsulation or broadcast options. See the "Example" section for the sequence of commands.
This command is required for all point-to-point subinterfaces; it is also required for multipoint subinterfaces for which dynamic address resolution is enabled. It is not required for multipoint subinterfaces configured with static address mappings.
Use the protocol ip ip-address option only when your router or access server will act as the BOOTP server for autoinstallation over Frame Relay.
For the voice-encap option on the Cisco MC3810, set the data segmentation size based on the port access rate. lists recommended data segmentation sizes for different port access rates. Also, when the voice-encap keyword is configured on the Cisco MC3810, all priority queuing, custom queuing, and weighted fair queuing is disabled on the interface.
Table 1 Recommended Data Segmentation Sizes
64 kbps
80 bytes
128 kbps
160 bytes
256 kbps
320 bytes
512 kbps
640 bytes
1536 kbps (full T1)
1600 bytes
2048 kbps (full E1)
1600 bytes
1 The data segmentation size is based for back-to-back Frame Relay. If sending traffic through an IGX with standard Frame Relay, add an extra 15 bytes to the recommended data segmentation size.
For more information about automatically installing router configuration files over a Frame Relay network, see the "Loading System Images and Microcode" chapter in the Configuration Fundamentals Configuration Guide.
Examples
The following example shows an Annex G connection being created by assigning the X.25 profile "NetworkNodeA" to the Frame Relay DLCI interface 20 on interface serial 1 (having enabled Frame Relay encapsulation on that interface):
Router(config)# interface serial1Router(config-if)# encapsulation frame-relayRouter(config-if)# frame-relay interface-dlci 20Router(config-fr-dlci)# x25-profile NetworkNodeAThe following example assigns DLCI 100 to serial subinterface 5.17:
Router(config)# interface serial 5Router(config-if)# interface serial 5.17Router(config-if)# frame-relay interface-dlci 100Related Commands
You can use the master indexes or search online to find documentation of related commands.
frame-relay class
show x25 context
To view operating configuration status details of an Annex G DLCI link, use the show x25 context command in EXEC mode.
show x25 context [interface number dlci number]
Syntax Description
interface number
(Optional) Specific logical X.25 VC interface.
dlci number
(Optional) Specific DLCI link.
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 12.0(3)T.
Sample Display
The following is sample output from the show x25 context command :
Router# show x25 contextSerial1 DLCI 20PROFILE DCE, address <none>, state R1, modulo 8, timer 0Defaults: idle VC timeout 0input/output window sizes 2/2, packet sizes 128/128Timers: T10 60, T11 180, T12 60, T13 60Channels: Incoming-only none, Two-way 1-1024, Outgoing-only noneRESTARTs 1/0 CALLs 0+0/0+0/0+0 DIAGs 0/0LAPB DCE, state CONNECT, modulo 8, k 7, N1 12056, N2 20T1 3000, T2 0, interface outage (partial T3) 0, T4 0VS 7, VR 6, tx NR 6, Remote VR 7, Retransmissions 0Queues: U/S frames 0, I frames 0, unack. 0, reTx 0IFRAMEs 111/118 RNRs 0/0 REJs 0/0 SABM/Es 14/1 FRMRs 0/0 DISCs 0/0describes significant fields shown in the display.
Related Commands
You can use the master indexes or search online to find documentation of related commands.
show x25 vc
show x25 profile
To view details of X.25 profiles on your router, issue the show x25 profile command in EXEC mode.
show x25 profile [name]
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 12.0(3)T.
Sample Display
The following is sample output from the show x25 profile command, showing all profiles configured on the same interface. By not specifying the X.25 profile name, the output shows all configured profiles for that interface.
Router# show x25 profileX.25 profile name:NetworkNodeANumber of references:2In use by:Annex G:Serial1 DLCI 20Annex G:Serial1 DLCI 30PROFILE DCE, address <none>, state R/Inactive, modulo 128, timer 0Defaults:idle VC timeout 5input/output window sizes 2/2, packet sizes 128/128Timers:T10 60, T11 180, T12 60, T13 60Channels:Incoming-only none, Two-way 1-128, Outgoing-only noneLAPB DCE, modulo 8, k 7, N1 default, N2 20T1 3000, T2 0, interface outage (partial T3) 0, T4 0X.25 profile name:NetworkNodeBNumber of references:1In use by:Annex G:Serial1 DLCI 40PROFILE DTE, address 1111, state R/Inactive, modulo 8, timer 0Defaults:idle VC timeout 0input/output window sizes 2/2, packet sizes 128/128Timers:T20 180, T21 200, T22 180, T23 180Channels:Incoming-only none, Two-way 1-1024, Outgoing-only noneLAPB DTE, modulo 8, k 7, N1 default, N2 20T1 3000, T2 0, interface outage (partial T3) 0, T4 0describes significant fields shown in the display.
Related Commands
You can use the master indexes or search online to find documentation of related commands.
show x25 vc
x25 profile
To configure an X.25 profile without allocating any hardware specific information, use the x25 profile command in global configuration mode. To delete this profile, use the no form of this command.
x25 profile name {dce | dte | dxe}
no x25 profile name
Syntax Description
name
X.25 profile name that you assign.
dce
Indicates a DCE interface.
dte
Indicates a DTE interface.
dxe
Indicates a DXE interface.
Default
dte
Command Mode
Global configuration
Usage Guidelines
This command first appeared in the Cisco IOS Release 12.0(3)T.
X.25 Profile X.25 Commands
lists the following X.25 commands in X.25 configuration mode which you may use to create your X.25 profile:
X.25 Profile LAPB Commands
lists the following LAPB commands in X.25 configuration mode which you may use to create your X.25 profile:
Example
The following example shows the NetworkNodeA profile being set as a DCE interface, and with x25 htc, x25 idle, x25 accept-reverse, and x25 modulo commands enabled:
Router(config)# x25 profile NetworkNodeA dceRouter(config-x25)# x25 htc 128Router(config-x25)# x25 idle 5Router(config-x25)# x25 accept-reverseRouter(config-x25)# x25 modulo 128Related Commands
You can use the master indexes or search online to find documentation of related commands.
show x25 profile
x25 route
To create an entry in the X.25 routing table (to be consulted for forwarding incoming calls and for placing outgoing packet assembler/disassembler (PAD) or protocol translation calls), use an appropriate form of the x25 route global configuration command. To remove an entry from the table, use the no form of the command.
x25 route [#position] [selection] [modification] disposition [xot-keepalive]
no x25 route [#position] [selection] [modification] dispositionSyntax Description
Default
No entry is created in the X.25 routing table.
Command Mode
Global configuration
Usage Guidelines
The enhanced x25 route command replaces the x25 map cmns command. The x25 route alias form of this command (supported in earlier releases) has been replaced by the x25 alias command.
The selection criteria source and dest-ext first appeared in Cisco IOS Release 11.3. The interface disposition to a CMNS destination first appeared in Cisco IOS Release 11.3; in prior releases, CMNS routing information was implied by maps defining an NSAP prefix for a CMNS hosts MAC address. The clear interface disposition option first appeared in Cisco IOS Release 11.3; in prior releases, the disposition was implicit in a route to the Null 0 interface. The modification elements are long-standing but newly applicable to all dispositions in Cisco IOS Release 11.3.
Note
Selection Options
Selection options specify match criteria. When a call matches all selection criteria in an X.25 route, then the specified modification and disposition are used for the call.
As many as four selection options can be used to determine the route:
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lists the selection options for the x25 route command. At least one selection or modification element must be specified.
Note
Regular expressions are used to allow pattern-matching operations on the addresses and user data. A common operation is to do prefix matching on the X.121 DNIC field and route accordingly. The caret (^) is a special regular expression character that anchors the match at the beginning of the pattern. For example, the pattern ^3306 will match all X.121 addresses with a DNIC of 3306.
Modification Options
Addresses typically need to be modified when traffic from a private network that uses arbitrary X.121 addresses must transit a public data network, which must use its own X.121 addresses. The easiest way to meet the requirement is to specify in the x25 route command a way to modify the private address into a network X.121 address or to modify a network X.121 address into a private address. The addresses are modified so that no change to the private addressing scheme is required.
The modification options use the standard UNIX regular expression substitution operations to change an X.25 field. A pattern match is applied to an address field, which is rewritten as directed by a rewrite pattern.
lists the modification options for the x25 route command. At least one selection or modification element must be specified.
Note
Source address. A modification of the source address is directed by the rewrite string using one of three possible match patterns. If the source source-pattern selection option is defined, it is used with the source-rewrite string to construct the new source address; otherwise, a destination-pattern regular expression is used (for backward compatibility) or a wildcard regular expression (.*) is used. In the rewrite-source argument, the backslash character (\) indicates that the digit immediately following the argument selects a portion of the matched address to be inserted into the new called address.
Destination address. A modification of the destination address is directed by the rewrite string using one of two possible match patterns. If the destination-pattern selection option is defined, it is used with the destination-rewrite string to construct the new destination address; otherwise, a wildcard regular expression (.*) is used. In the rewrite-dest argument, the backslash character (\) indicates that the digit immediately following the argument selects a portion of the original called address to be inserted into the new called address.
Refer to , , and respectively, for summaries of pattern matching, character matching, and pattern rewrite elements. Note that up to nine pairs of parentheses can be used to identify patterns to be included in the modified string. A more complete description of the pattern-matching characters is found in the "Regular Expressions" appendix in the Dial Solutions Command Reference.
Table 8 Pattern Matching for X.25 Route Selection and Modification Options
*
Matches 0 or more occurrences of the preceding character.
+
Matches 1 or more occurrences of the preceding character.
?
Matches 0 or 1 occurrences of the preceding character.1
1 Precede the question mark with Ctrl-V to prevent the question mark from being interpreted as a help command.
Disposition Option
The xot-source disposition option can improve the resilience of the TCP connection if, for instance, a loopback interface is specified. By default, a TCP connection's source IP address is that of the interface used to initiate the connection; a TCP connection will fail if either the source or destination IP address is no longer valid. Because a loopback interface never goes down, its IP address is always valid. Any TCP connections originated using a loopback interface can be maintained as long as a path exists to the destination IP address, which may also be the IP address of a loopback interface.
lists the disposition choices for the x25 route command. You must select one of these choices.
XOT Keepalive Options
TCP maintains each connection using a keepalive mechanism that starts with a default time period and number of retry attempts. If a received XOT connection is dispatched using a route with explicit keepalive parameters, those values will be used for the TCP connection. If an XOT connection is sent using a route with explicit keepalive parameters, those values will be used for the TCP connection.
lists and describes the xot-keepalive options for the x25 route command.
X.25 Routing Action when a Match Is Found
If a matching route is found, the incoming call is forwarded to the next hop depending on the routing entry. If no match is found, the call is cleared. If the route specifies a serial interface running X.25 or a broadcast interface running CMNS, the router attempts to forward the call to that host. If the interface is not operational, the subsequent routes are checked for forwarding to an operational interface. If the interface is operational but out of available virtual circuits, the call is cleared. Otherwise, the expected Clear Request or Call Accepted message is forwarded back toward the originator. A call cannot be forwarded out the interface on which it arrived.
If the matching route specifies an XOT disposition, a TCP connection is established to port 1998 at the specified IP address, which must be an XOT host. The Call Request packet is forwarded to the remote host, which applies its own criteria to handle the call. If, upon receiving an XOT call, a routing table entry is not present, or the destination is unavailable, a Clear Request is sent back and the TCP connection is closed. Otherwise, the call is handled and the expected Clear Request or Call Accepted packet is returned. Incoming calls received via XOT connections that match a routing entry specifying an XOT destination are cleared. This restriction prevents Cisco routers from establishing an XOT connection to another router that would establish yet another XOT connection.
Examples
The following example uses regular expression pattern matching characters to match just the initial portion of the complete X.25 address. Any call with a destination address beginning with 3107 that is received on an interface other than serial 0 is forwarded to serial 0.
x25 route ^3107 interface serial 0The following example routes the X.25 call to the specified Annex G DLCI link. You must include both interface number and DLCI number. It is this combination of both these numbers that indicates the logical X.25 interface over Frame Relay.
x25 route ^2222 interface serial 1 dlci 20The following example prevents X.25 routing for calls that do not specify a source address:
x25 route source ^$ clearThe following example configures alternate XOT hosts for the routing entry. If the first address listed is not available, subsequent addresses are tried until a connection is made. If no connection can be formed, the call is cleared.
x25 route ^3106$ xot 172.20.2.5 172.20.7.10 172.10.7.9The following example clears calls that contain a 3 in the source address. The disposition keyword clear is new:
x25 route source 3 clearThe following example clears calls that contain two consecutive 3's in the source address:
x25 route source 33 clearThe following example clears a call to the destination address 9999:
x25 route ^9999$ clearThe following example specifies a route for specific source and destination addresses. (The ability to combine source and destination patterns is a new feature.)
x25 route ^9999$ source ^333$ interface serial 0The following example routes the call to the XOT host at the specified IP address. The disposition keyword xot is new. In prior releases the keyword ip was used.
x25 route ^3333$ xot 172.21.53.61The following example routes calls containing the destination extension address preamble 11.1234:
x25 route dest-ext ^11.1234.* interface serial 0The following example rewrites the destination address as 9999. There must be a minimum of four 8's in the address. (8888888 will change to 9999.)
x25 route 8888 substitute-dest 9999 interface serial 0The following example substitutes only part of the destination address. "^88" specifies the original destination string must begin with 88. "(.*)" indicates the string can end with any number, 0-9, and can be more than one digit. "99\1" changes the destination address to 99 plus whatever matches ".*" in the original destination address. For example, 8881 will change to 9981.
x25 route ^88(.*) substitute-dest 99\1 interface serial 0The following example substitutes only part of the destination address and also removes a specified number of digits from the address. "^88" specifies the original destination string must begin with 88. "(..)" matches any two digits. "(.*)" specifies the string can end with any number, 0-9, and can occur zero or more times. Thus any address that starts with 88 and has four or more digits will be rewritten to start with 99 and omit the third and fourth digits. For example, 881234 will change to 9934.
x25 route ^88(..)(.*) substitute-dest 99\2 interface serial 0The following example looks for a specified destination address and changes the source address. "9999" is the destination address. The original source address changes to "2222" because the call is made to the destination 9999.
x25 route ^9999$ substitute-source 2222 interface serial 0The following example rewrites the source address based on the source address. "9999" matches any destination address with four consecutive 9s. "^...(.*)" matches any source address with at least three digits; the command removes the first three digits and rewrites any digits after the first three as the new source address. For example, a call to 9999 from the source address 77721 will be forwarded using the calling address 21 and the called address 9999.
x25 route 9999 source ^...(.*) substitute-source \1 interface serial 0The following example adds a digit to the source and destination addresses patterns. "09990" is the destination address pattern. The source can be any address. "9\0" specifies to add a leading 9 to the destination address pattern. "3\0" specifies to add a leading 3 to the source address pattern. For example, a call using source 03330 and destination 09990 will change to 303330 and 909990, respectively.
x25 route 09990 source .* substitute-dest 9\0 substitute-source 3\0 interface serial 0Related Commands
You can use the master indexes or search online to find documentation of related commands.
show x25 route
Debug Commands
The debug x25 command has been modified to accommodate Annex G. Use the debug x25 annexg command to debug Annex G.
debug x25
To display information about X.25 traffic, use one of the following debug x25 commands. The commands allow you to display all information or an increasingly restrictive part of the information.
CautionThis command is processor intensive and can render the router useless. Use this command only when the aggregate of all reportable X.25 traffic is fewer than five packets per second. The generic forms of this command should be restricted to low-speed, low-usage links running below 19.2 kbps. Because the debug x25 vc command and the debug x25 vc events command display traffic for only a small subset of virtual circuits, they are safer to use under heavy traffic conditions, as long as events for that virtual circuit are fewer than 25 packets per second.
To display information about all X.25 traffic, including traffic for X.25, CMNS, and XOT services, use the debug x25 EXEC command. The no form of this command disables debugging output.
[no] debug x25 [events | all]
To display information about a specific X.25 service class, use the following form of the debug x25 EXEC command:
[no] debug x25 {only | cmns | xot} [events | all]
To display information about a specific X.25 or CMNS context, use the following form of the debug x25 EXEC command:
[no] debug x25 interface {serial-interface | cmns-interface mac mac-address} [events | all]
To display information about a specific X.25 or CMNS virtual circuit, use the following form of the debug x25 EXEC command:
[no] debug x25 interface {serial-interface | cmns-interface mac mac-address} vc number
[events | all]To display information about traffic for all virtual circuits using a given number, use the following form of the debug x25 EXEC command. The no form of this command removes the filter for a particular virtual circuit from the debug x25 all or debug x25 events output.
[no] debug x25 vc number [events | all]
To display information about traffic to or from a specific XOT host, use the following form of the debug x25 xot EXEC command:
[no] debug x25 xot [remote ip-address [port number]] [local ip-address [port number]]
[events | all]To display information about an interface running PPP over an X.25 session, use the debug x25 aodi EXEC command. The no form of this command disables debugging output.
[no] debug x25 aodi
To display information about interfaces running an Annex G (X.25 over Frame Relay) session, use the debug x25 annexg EXEC command. The no form of this command disables debugging output.
[no] debug x25 annexg
Syntax Description
Usage Guidelines
This command is particularly useful for diagnosing problems encountered when placing calls. The debug x25 all output includes data, control messages, and flow control packets for all of the router's virtual circuits.
All debug x25 command forms can take either the events or all keyword. The keyword all is the default and causes all packets meeting the other debug criteria to be reported. The keyword events omits reports of any Data or Receive Ready (RR) flow control packets; the normal flow of Data and RR packets is commonly large as well as less interesting to the user, so event reporting can significantly decrease the processor load induced by debug reporting.
The debug x25 interface command is useful for diagnosing problems encountered with a single X.25 or CMNS host or virtual circuit.
Because no interface is specified by the debug x25 vc command, traffic on any virtual circuit that has the specified number is reported.
Virtual circuit zero (vc 0) cannot be specified. It is used for X.25 service messages, such as RESTART packets, not virtual circuit traffic. Service messages can be monitored only when no virtual circuit filter is used.
The debug x25 xot output allows you to restrict the debug output reporting to XOT traffic for one or both hosts or host/port combinations. Because each XOT virtual circuit uses a unique TCP connection, an XOT debug request that specifies both host addresses and ports will report traffic only for that virtual circuit. Also, you can restrict reporting to sessions initiated by the local or remote router by, respectively, specifying 1998 for the remote or local port. (XOT connections are received on port 1998.)
Use the debug x25 aodi command to display interface PPP events running over an X.25 session and to debug X.25 connections between a client and server configured for AO/DI.
Use the debug x25 annexg command to display interface Annex G events (X.25 over Frame Relay).
Sample Display
The following is sample output from the debug x25 annexg command (see for field descriptions):
Router# debug x25 annexgX.25 over FR (Annex-G) debugging is on03:25:30:Se0 DLCI 18:X.25 I R1 Call (17) 8 lci 103:25:30: From(7):2193330 To(8):2192181803:25:30: Facilities:(0)03:25:30: Call User Data (4):0x01000000 (pad)03:25:30:Se0 DLCI 18:X.25 O R1 Call Confirm (5) 8 lci 103:25:30: From(0): To(0):03:25:30: Facilities:(0)03:25:30:annexg_restart_tx:sending pak to Serial003:25:30:annexg_restart_tx:sending pak to Serial003:25:30:annexg_restart_tx:sending pak to Serial0The following is sample output from an X.25 Restart event, a Call setup, data exchange, and Clear. The first two lines describe a Restart service exchange.
Router# debug x25Serial0: X.25 I R/Inactive Restart (5) 8 lci 0Cause 7, Diag 0 (Network operational/No additional information)Serial0: X.25 O R3 Restart Confirm (3) 8 lci 0Serial0: X.25 I P1 Call (15) 8 lci 1From(6): 170091 To(6): 170090Facilities: (0)Call User Data (4): 0xCC000000 (ip)Serial0: X.25 O P3 Call Confirm (3) 8 lci 1Serial0: X.25 I D1 Data (103) 8 lci 1 PS 0 PR 0Serial0: X.25 O D1 Data (103) 8 lci 1 PS 0 PR 1Serial0: X.25 I P4 Clear (5) 8 lci 1Cause 9, Diag 122 (Out of order/Maintenance action)Serial0: X.25 O P7 Clear Confirm (3) 8 lci 1describes significant fields shown in the display.
The following example shows a sequence of increasingly restrictive debug x25 commands:
Router# debug x25X.25 packet debugging is onRouter# debug x25 eventsX.25 special event debugging is onRouter# debug x25 interface serial 0X.25 packet debugging is onX.25 debug output restricted to interface Serial0Router# debug x25 vc 1024X.25 packet debugging is onX.25 debug output restricted to VC number 1024Router# debug x25 interface serial 0 vc 1024X.25 packet debugging is onX.25 debug output restricted to interface Serial0X.25 debug output restricted to VC number 1024Router# debug x25 interface serial 0 vc 1024 eventsX.25 special event debugging is onX.25 debug output restricted to interface serial 0X.25 debug output restricted to VC number 1024The following examples show the normal sequence of events for both the AO/DI client and server sides:
Client Side
Router# debug x25 aodiPPP-X25: Virtual-Access1: Initiating AODI call requestPPP-X25: Bringing UP X.25 AODI VCPPP-X25: AODI Client Call Confirm Event ReceivedPPP-X25: Cloning interface for AODI is Di1PPP-X25: Queuing AODI Client Map EventPPP-X25: Event:AODI Client MapPPP-X25: Created interface Vi2 for AODI servicePPP-X25: Attaching primary link Vi2 to Di1PPP-X25: Cloning Vi2 for AODI service using Di1PPP-X25: Vi2: Setting the PPP call direction as OUTPPP-X25: Vi2: Setting vectors for RFC1598 operation on BRI3/0:0 VC 0PPP-X25: Vi2: Setting the interface default bandwidth to 10 KbpsPPP-X25: Virtual-Access2: Initiating AODI call requestPPP-X25: Bringing UP X.25 AODI VCPPP-X25: AODI Client Call Confirm Event ReceivedServer Side
Router# debug x25 aodiPPP-X25: AODI Call Request Event ReceivedPPP-X25: Event:AODI Incoming Call RequestPPP-X25: Created interface Vi1 for AODI servicePPP-X25: Attaching primary link Vi1 to Di1PPP-X25: Cloning Vi1 for AODI service using Di1PPP-X25: Vi1: Setting vectors for RFC1598 operation on BRI3/0:0 VC 1PPP-X25: Vi1: Setting the interface default bandwidth to 10 KbpsPPP-X25: Binding X.25 VC 1 on BRI3/0:0 to Vi1Related Commands
debug ppp bap
debug ppp bap negotiation
debug ppp multilink
debug ppp negotiation
