IOS Router Frame Relay Command Glossary	Cisco IOS Command References In depth descriptions of all IOS command options

bridge bridge-group protocol {ieee | dec}	IOS Command Reference

This command enables the router's bridging engine, identifies the bridging process with a bridge-group number, and specifies the particular spanning tree algorithm used to avoid bridging loops. All routers on the network that expect to bridge between each other need to share the same bridge-group number. The selected spanning tree protocol must also be consistent on each router. In bridging examples, Atlanta, Boston, and Chicago are all configured as bridge 1 and all run the IEEE spanning tree algorithm.

bridge-group bridge-group	IOS Command Reference

Once a bridging engine is enabled on the router with the bridge bridge-group# protocol {ieee | dec}command, the bridging process must be applied to the individual interfaces. This command applies the bridging process to an interface. All non-routed traffic is bridged between interfaces that share the same bridge-group number. In bridging examples, the interfaces on Atlanta, Boston, and Chicago all belong to bridge-group 1.

description descriptive-string	IOS Command Reference

A description can be added to an interface to help keep track of PVCs (e.g. Frame Relay to Boston)

enable secret password

IOS Command Reference Enable Secret Command

IOS Command Reference Enable Password Command

This command defines the enable secret password used to protect access to privileged exec commands. The password is case sensitive and can be defined on the router two different ways. A password set with the "enable password" command is stored as clear text, whereas a password set with "enable secret" is encrypted. For security, configuring the router with an enable secret is preferred. The enable secret always takes precedence if both enable secret and enable password are set.

Note: The unencrypted form of the password "cisco" is shown in the sample configurations. In an actual configuration, the password would appear in an encrypted form: (i.e. enable secret 7 13061E010803 --where 7 denotes the encryption type and 13061E010803 is an encrypted form of the password cisco.) When entering or making changes to the enable secret, always type the password in its unencrypted form. Do not enter the encryption type (7); it is set automatically.

encapsulation frame-relay [cisco | ietf]	IOS Command Reference

This command specifies frame relay encapsulation.

Note: IETF frame-relay encapsulation is necessary when connecting to non-Cisco routers. The router defaults to Cisco frame-relay encapsulation if IETF is not specified. To configure IETF frame-relay encapsulation, use the "encapsulation frame-relay IETF" form of this command. Encapsulation types must match on both routers.

frame-relay interface-dlci dlci [broadcast]	IOS Command Reference

This command assigns a Data Link Connection Identifier (DLCI) number to the corresponding frame-relay subinterface. A DLCI is assigned by the local frame relay provider for every Permanent Virtual Circuit (PVC) connected to the router. DLCI numbers are NOT exchanged between routers. DLCI numbering at one frame relay site is mutually exclusive from DLCI numbering at another site. This concept is illustrated in the examples. DLCI numbers for Atlanta (16 and 17) need not match DLCI numbers for Boston (16) and Chicago (16). By the same token, it is OK for Boston and Chicago to both use DLCI 16.

The broadcast keyword is optional and should only be included if broadcast packets (e.g. IP RIP or IPX RIP/SAP updates) need to be forwarded out of the subinterface. In static routing examples, routing updates are not required and the keyword is omitted.

Note: In IOS versions later than 11.1(5), all point-to-point subinterfaces will forward broadcast packets by default and the option cannot be disabled. In static routing examples, even though broadcast traffic is enabled, operation is not affected as other precautions are taken to prevent the forwarding of broadcast traffic out of the subinterface (e.g. routing protocols are disabled for the subinterface).

frame-relay lmi-type {ansi | cisco | q933a}	IOS Command Reference

This command configures the router with which frame-relay Local Management Interface (LMI) type to expect from the frame relay provider. LMI is a frame relay control protocol sent to the router from the frame relay switch at the service provider and is not exchanged between routers. The LMI type at one location does NOT have to match the LMI type at other locations. To illustrate this point, the examples have Boston (Cisco LMI) using a different LMI type than Atlanta (ANSI Annex D LMI).

Supported LMI Types

cisco	Generic "gang of four" LMI (default)
ansi	ANSI Annex D
q933a	CCITT Q933a

Note: When the LMI type is set for "cisco", the command will not appear in the configuration since this is the default value.

frame-relay map ip ip-address dlci [broadcast]	IOS Command Reference

This command is used in multipoint frame-relay examples and defines a static mapping between a protocol address and a frame-relay Data Link Connection Identifier (DLCI). A DLCI is assigned by the local frame relay provider for every Permanent Virtual Circuit (PVC) connected to the router. DLCI numbers are NOT exchanged between routers. DLCI numbering at one frame relay site is mutually exclusive from DLCI numbering at another site. This concept is illustrated in the examples. DLCI numbers for Atlanta (16 and 17) need not match DLCI numbers for Boston (16) and Chicago (16). By the same token, it is OK for Boston and Chicago to both use DLCI 16.

The broadcast keyword is optional and should only be included if broadcast packets (e.g. IP RIP or IPX RIP/SAP updates) need to be forwarded out of the subinterface. In static routing examples, routing updates are not required and the keyword is omitted.

In multipoint frame-relay examples, Atlanta uses DLCI 16 to reach Boston (IP address 172.16.1.2). Therefore, Atlanta defines a static frame relay map with the command "frame-relay map ip 172.16.1.2 16". Also, Boston contains static frame-relay maps to use DLCI 16 for both Atlanta and Chicago because traffic destined to Chicago must first be sent over the PVC to Atlanta. Atlanta will then redirect the packet out its PVC to Chicago.

hostname name	IOS Command Reference

This command gives the router an identity and changes the command prompt (e.g. Atlanta#). In dial up networking applications, this name may be used for PPP authentication purposes.

interface Serial0.subinterface# [point-to-point | multipoint]	IOS Command Reference

This command creates a logical frame-relay subinterface and defines it as a point-to-point or multipoint connection. A subinterface is treated as if it where a separate interface dedicated for a PVC to a remote site. "Serial0" indicates that the subinterface belongs to the physical serial0 interface and "16" is the unique subinterface ID number. The subinterface ID number can be any unique value between zero and 4,294,967,295 and does not have to be in any particular order (i.e. it is not necessary to begin with 1 and sequentially progress with 2,3,…etc.). In fact, to reduce confusion, it is good practice to identify a subinterface with the same number as the DLCI used on that subinterface.

Info On Subinterfaces Faxback Doc #subifs

ip address ip-address subnet-mask	IOS Command Reference

This command configures an interface with an IP address and subnet mask. In IP routing examples, 10.1.1.1 is the IP address of the ethernet interface in Atlanta and 255.0.0.0 is the corresponding subnet mask. For examples in which IP is bridged, all interfaces on the router are configured with the same IP address because the router is reduced to a simple node on an IP network with only one IP address.

ip classless	IOS Command Reference

This command allows the router to forward packets destined to an unrecognized subnet of a directly connected network onto the best supernet route. For example, the 10.0.0.0 network is subnetted with a 255.255.255.0 subnet mask. Let's pretend that the 10.1.1.0 subnet is directly attached to ethernet0 (i.e. interface ethernet0 has the ip address 10.1.1.1 255.255.255.0). Suppose the router receives a packet destined to 10.2.2.0 and the router has no explicit entry for this network. Without the IP classless command, the packet is discarded. However, with the IP classless command, the packet is not discarded, but instead forwarded to the best supernet route if one exists (i.e. a default route).

ip http server	IOS Command Reference

This command allows remote configuration and management of the router via a web browser and is available in IOS software versions 11.1 and higher. This command has been included as a convenience to the user and is not necessary for configurations to operate properly.

ip route network subnet-mask {address | interface}	IOS Command Reference

This command defines a static IP route. The first and second fields define the destination network number and subnet mask. The third field defines the next hop and can either be specified as an IP address or an interface.

Note: Under most circumstances, the third field contains the IP address of the next hop. However, for routes over unnumbered point-to-point subinterfaces, specify the subinterface used to reach the destination.

In some statically routed examples, Atlanta has a static IP route to Boston (e.g. ip route 20.0.0.0 255.0.0.0 Serial0.16). In these cases, Atlanta knows that IP network 20.0.0.0 (Boston) with a subnet mask of 255.0.0.0 can be reached via interface Serial0.16. In other examples, a static IP default route is defined using 0.0.0.0 as both the destination network number and subnet mask. The default route is used if the router does not already have an explicit routing table entry for a destination network. For instance, in some examples, "ip route 0.0.0.0 0.0.0.0 Serial0.16" defines a static IP default route on Boston to Atlanta. In these cases, Boston forwards all packets not destined for its local network onto Atlanta using interface Serial0.16.

ip subnet-zero	IOS Command Reference

When subnetting an IP network, the all zeroes subnet and the all ones subnet are normally discarded as invalid. This command allows the router to recognize the zero subnet range as a valid range of addresses. This command is not necessary if the network is not subnetted, although it does not hurt to include the command in the configuration. For instance, if a router is configured with the address of 206.1.1.1 255.255.255.192 without including the ip subnet-zero command, the error "Bad mask /26 for address 206.1.1.1" would be displayed because 206.1.1.1 is part of the zero subnet.

ip unnumbered source-interface	IOS Command Reference

This command configures a point-to-point interface to use unnumbered IP addressing. IP unnumbered helps conserve IP addresses and network space. Essentially, the IP address of the source interface is borrowed and used on the serial interface. In the examples, Ethernet0 is used as the source interface.

Info On IP Unnumbered Faxback Doc #ip_unnum

ipx network network [encapsulation encapsulation-type [secondary]]	IOS Command Reference

This command binds an IPX network number and frame type to an interface. If no IPX frame-type is specified, the router will default to Novell 802.3 encapsulation. The network number and frame-type should match the settings bound to existing IPX servers and clients. If no servers exist at the site a new, unique IPX network number must be created.

Possible IPX Frame Types

novell-ether	Novell Ethernet 802.3 (default)
arpa	Novell Ethernet II
sap	IEEE 802.2 on Ethernet, FDDI, Token Ring
snap	IEEE 802.2 SNAP on Ethernet, Token Ring, FDDI

It is possible to add more than one IPX network to the same LAN interface as long as different frame types are used. The keyword "secondary" flags the router to add a network as an additional network. Secondary networks can be added for each additional frame type. For instance, in IPX examples, Atlanta has two networks on Ethernet0. IPX network 100 is using 802.2 framing and IPX network 101 is using 802.3 framing.

The frame relay interface also requires its own unique IPX network segment. In IPX examples, the IPX network number for the segment between Atlanta and Boston is AAAA. Therefore, Atlanta's interface Serial0.16 to Boston is assigned the AAAA IPX network number and Boston's interface Serial0.16 to Atlanta is also assigned the AAAA IPX network number.

Note: Depending on the version of IOS, the field "encapsulation NOVELL-ETHER" may not appear in the configuration because NOVELL-ETHER is the default value.

ipx route network network.node	IOS Command Reference

This command creates a static IPX route. The first field specifies the destination IPX network number. The second field specifies the IPX address of the next hop used to reach the destination. Normally, routing information would be resolved automatically with a routing protocol (e.g. IPX RIP/SAP). However, in the static IPX routing examples, routing protocols are disabled on the frame relay interfaces. Instead, each router has a static IPX route entry for every remote IPX internal and external network number.

For example, For workstations in Atlanta to access BostonFS, Atlanta requires a static route to the internal IPX network number of BostonFS (IPX network 2000). The command "ipx route 2000 AAAA.0000.0cbb.2222" informs Atlanta that IPX network 2000 can be reached via the next hop IPX address AAAA.0000.0cbb.2222. AAAA is the IPX network number of the segment between Atlanta and Boston. 0000.0cbb.2222 is the MAC address Boston uses for the IPX routing process. This is the same MAC address that appears in Boston's ipx routing command.

ipx router rip	IOS Command Reference

This command enables the IPX RIP/SAP routing engine.

Note: Once the command "ipx routing" is entered, IPX RIP/SAP is automatically enabled on all networks and will not appear in the configuration listing because it is the default action. However, in static IPX routing examples, this command will show up in the configuration because the default setting is modified when disabling IPX RIP updates on frame relay subinterfaces.

ipx routing [node-address]	IOS Command Reference

This command enables the IPX RIP/SAP routing engine on the router. The router associates the specified node-address with the IPX routing process. If no node-address value is supplied the router will automatically supply a node address for the routing process. It is recommended that the router assign the address automatically so that accidental node address duplication does not occur.

ipx sap service-type name network.node IPX-socket hop-count	IOS Command Reference

This command creates a static IPX service announcement and defines the IPX service-type (e.g. type 4 = file service), name, IPX address, IPX socket number, and hops to reach the service. Normally, service announcement information is resolved automatically with a routing protocol (e.g. IPX RIP/SAP). However, in static IPX routing examples, routing protocols are disabled on frame relay interfaces. Instead, a static SAP is created for every remote IPX service that must be reached.

For instance, if clients in Atlanta wish to access BostonFS, Atlanta needs a static SAP for BostonFS. The command "ipx sap 4 BostonFS 2000.0000.0000.0001 451 2" tells Atlanta that an IPX type 4 file service named BostonFS has an IPX address of 2000.0000.0000.0001, uses IPX socket 451, and is two hops away. 2000 is the internal IPX network number of the file server. 0000.0000.0001 is the internal node number of the file server. The service type, service name, and socket number will vary depending on the service (e.g. print servers, file servers).

ipx sap-interval interval	IOS Command Reference

This command specifies how often (in minutes) the router sends IPX SAPs out of an interface or subinterface. The default value is one minute. In static IPX routing examples, IPX SAPs are disabled on an interface by setting the interval to zero.

line vty 0 4	IOS Command Reference

This command defines the number of virtual terminal (telnet) sessions to the router. In the examples, five telnet sessions can be accommodated, numbered 0 to 4. The number of telnet sessions supported varies by platform and amount of memory.

network network	IOS Command Reference

This command adds an IP network to RIP routing updates advertised by the router. Only directly connected IP networks should be added. In the examples, Atlanta includes network 10.0.0.0 in its router rip definition because this is directly attached to Ethernet0. Likewise, Boston will include any directly attached networks in its router rip configuration.

Note: Only the major network number is entered for RIP. If a subnet is entered (e.g. 10.1.1.0), it is automatically rounded off to the major network number (e.g. 10.0.0.0).

network address wildcard-mask area area-id	IOS Command Reference

The network command designates the OSPF area for an interface with the specified IP address. For example, the command "network 10.1.1.1 0.0.0.0 area 0" specifies that the interface whose IP address is 10.1.1.1 belongs in OSPF area zero. 10.1.1.1, is the ip address to which the wildcard-mask 0.0.0.0 is applied. When the wildcard-mask is broken into its binary form, the zero bits indicate a match condition whereas the one bits indicate a wildcard "don't care" condition. Thus the 0.0.0.0 mask indicates to place only the interface assigned the 10.1.1.1 address into area zero.

If properly used, the wildcard-mask offers a shortcut method to put interfaces into the same area with one configuration line. For instance, the command "network 10.0.0.0 0.255.255.255 area 0" specifies that any interface whose IP address begins with 10 should be placed into OSPF area zero. The 255s (eight binary one's) in the second, third, and fourth octets indicate to ignore the contents in the respective octets of the address.

The area-id (e.g. area 0) specifies the OSPF area to which the interface is assigned. All OSPF networks require area 0 for the backbone. For those not intimately familiar with OSPF design, it is recommended to keep all routers in area zero.

OSPF Design Guide Faxback Doc #ospf

no auto-summary	IOS Command Reference

This command turns off auto-summarization of routes. When using RIP version 2, variable length subnet masks are accommodated.

In the examples, no ip address (or IPX network number) is configured on the physical Serial0 interface because all protocol address information is moved to the logical subinterfaces.

no ip domain-lookup	IOS Command Reference

This command disables the router from translating unfamiliar words typed during a console session into IP addresses. During this lookup, a user cannot enter any commands into the router. Though a useful feature to some, many find it frustrating to wait for the lookup to timeout for every mistyped command. Therefore, the command has been included in the configurations as a convenience and is not a necessary parameter for configurations to operate properly.

no ip routing	IOS Command Reference

IP routing is on by default. For examples in which IP is bridged, this command disables the IP routing engine.

no network network	IOS Command Reference

This command excludes the specified IPX network number in IPX RIP routing broadcasts. In static IPX routing examples, IPX RIP is disabled for frame-relay subinterface network numbers (e.g. AAAA and BBBB).

password password	IOS Command Reference

This command sets the password for either a console, telnet, or modem connection into the router. A console password is set under line con, a telnet password is set under line vty, and a modem connection password is also set under the corresponding line command.

router ospf process-id	IOS Command Reference

This command enables the OSPF routing process on the router. The OSPF process-id is a numeric value local to the router. It does not have to match process-ids on other OSPF routers. In OSPF examples, notice that Atlanta, Boston, and Chicago are using different OSPF process IDs. This is OK.

Note: It is possible to run multiple OSPF processes on the same router, but is not recommended as it creates multiple database instances that add extra overhead to the router.

OSPF Design Guide Faxback Doc #ospf

router rip	IOS Command Reference

This command enables the RIP routing process on the router for TCP/IP.

version 2	IOS Command Reference

This command specifies RIP version 2 as the routing protocol and is available in IOS software versions 11.1 and later. RIP version 2 is backwards compatible with RIP version 1 and adds the enhanced capability to support variable length subnet masks.

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