[no] ldp
config>router
Supported on all 7210 SAS platforms as described in this document
Commands in this context configure LDP parameters. LDP is not enabled by default and must be explicitly enabled (no shutdown).
To suspend the LDP protocol, use the shutdown command. Configuration parameters are not affected. The LDP instance must first be disabled using the shutdown command before being deleted.
The no form of this command deletes the LDP protocol instance, removing all associated configuration parameters.
[no] aggregate-prefix-match
config>router>ldp
Supported on all 7210 SAS platforms as described in this document
The command enables LDP to use the aggregate prefix match function instead of requiring an exact prefix match.
When this command is enabled, LDP performs the following procedures for all prefixes. When an LSR receives a FEC-label binding from an LDP neighbor for a specific FEC1 element, it installs the binding in the LDP FIB if:
it is able to perform a successful longest IP match of the FEC prefix with an entry in the routing table
the advertising LDP neighbor is the next-hop to reach the FEC prefix
When the FEC-label binding has been installed in the LDP FIB, LDP programs an NHLFE entry in the egress datapath to forward packets to FEC1. LDP also advertises a new FEC-label binding for FEC1 to all its LDP neighbors.
When a new prefix appears in the routing table, LDP inspects the LDP FIB to determine if this prefix is a closer match for any of the installed FEC elements. For any FEC for which this is true, LDP may have to update the NHLFE entry for this FEC.
When a prefix is removed from the routing table, LDP checks the LDP FIB for all FEC elements that matched this prefix to determine if another match exists in the routing table. If another match exists, it updates the NHLFE entry. If not, it sends a label withdraw message to its LDP neighbors to remove the binding.
If the next hop for a routing prefix changes, LDP updates the LDP FIB entry for the FEC elements that matched this prefix. It also updates the NHLFE entry for these FEC elements.
The no form of this command disables the use of the aggregate prefix match function and deletes the configuration. LDP then performs only exact prefix matching for FEC elements.
no aggregate-prefix-match
prefix-exclude policy-name [policy-name... (up to 5 max)]
no prefix-exclude
config>router>ldp>aggregate-prefix-match
Supported on all 7210 SAS platforms as described in this document
This command specifies the policy name containing the prefixes to be excluded from the aggregate prefix match function. Against each excluded prefix, LDP performs an exact match of a specific FEC element prefix, instead of a longest prefix match of one or more LDP FEC element prefixes when it receives a FEC-label binding or when a change to this prefix occurs in the routing table.
The no form of this command removes all policies from the configuration.
no prefix-exclude.
Specifies the import route policy name. Allowed values are any string up to 32 characters long composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.
export policy-name [policy-name … (up to 5 max)]
no export
config>router>ldp
Supported on all 7210 SAS platforms as described in this document
This command specifies the export route policies that determine which routes are exported to LDP. Policies are configured in the config>router>policy-options context.
If no export policy is specified, non-LDP routes are not exported from the routing table manager to LDP, and LDP-learned routes are exported only to LDP neighbors. The currenty implementation of the export policy (outbound filtering) can be used only to add FECs for label propagation. The export policy does not control propagation of FECs that an LSR receives from its neighbors.
If multiple policy names are specified, the policies are evaluated in the order they are specified. The first policy that matches is applied. If multiple export commands are issued, the last command entered overrides the previous command. A maximum of five policy names can be specified. Specified names must already be defined.
The no form of this command removes all policies from the configuration.
no export
Specifies the export route policy name. Allowed values are any string up to 32 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.
fast-reroute
no fast-reroute
config>router>ldp
Supported on all 7210 SAS platforms as described in this document
This command enables LDP Fast-Reroute (FRR). When enabled, LDP uses both the primary next hop and LFA next hop, when available, for resolving the next hop of an LDP FEC against the corresponding prefix in the routing table. This results in LDP programming a primary NHLFE and a backup NHLFE into the forwarding engine for each next hop of a FEC prefix for the purpose of forwarding packets over the LDP FEC.
The backup NHLFE is enabled for each affected FEC next hop when any of the following events occurs.
An LDP interface goes operationally down or is administratively shut down. In this case, LDP sends a neighbor/next-hop down message to the IOM for each LDP peer it has adjacency with over this interface.
An LDP session to a peer goes down because the Hello or keepalive timer has expired over a specific interface. In this case, LDP sends a neighbor/next-hop down message to the IOM for this LDP peer only.
The TCP connection used by a link LDP session to a peer goes down, because, for example, next-hop tracking of the LDP transport address in RTM brings down the LDP session. In this case, LDP sends a neighbor/next-hop down message to the IOM for this LDP peer only.
A BFD session, enabled on a T-LDP session to a peer, times out and causes the link LDP session to the same peer, which uses the same TCP connection as the T-LDP session, to also go down. In this case, LDP sends a neighbor/next-hop down message to the IOM for this LDP peer only.
A BFD session enabled on the LDP interface to a directly connected peer times out and brings down the link LDP session to this peer. In this case, LDP sends a neighbor/next-hop down message to the IOM for this LDP peer only. BFD support on LDP interfaces is a recent feature that provides faster tracking of link LDP peers.
The tunnel-down-damp-time command or the label-withdrawal-delay command, when enabled, do not cause the corresponding timer to be activated for a FEC as long as a backup NHLFE is still available.
Because LDP can detect the loss of a neighbor/next-hop independently, it is possible that it will switch to the LFA next hop while IGP is still using the primary next hop. Also, when the interface for the previous primary next hop is restored, IGP may reconverge before LDP completes the FEC exchange with its neighbor over that interface. This may cause LDP to deprogram the LFA next hop from the FEC and blackhole traffic. To avoid this situation, IGP-LDP synchronization should be enabled on the LDP interface.
When the SPF computation determines there is more than one primary next hop for a prefix, it does not program an LFA next hop in RTM. The LDP FEC will resolve to the multiple primary next hops that provide the required protection.
The no form of this command disables LDP FRR.
no fast-reroute
fec-originate ip-prefix/mask [advertised-label in-label] [swap-label out-label] interface interface-name
fec-originate ip-prefix/mask [advertised-label in-label] next-hop ip-address [swap-label out-label]
fec-originate ip-prefix/mask [advertised-label in-label] next-hop ip-address [swap-label out-label] interface interface-name
fec-originate ip-prefix/mask [advertised-label in-label] pop
no fec-originate ip-prefix/mask interface interface-name
no fec-originate ip-prefix/mask next-hop ip-address
no fec-originate ip-prefix/mask next-hop ip-address interface interface-name
no fec-originate ip-prefix/mask pop
config>router>ldp
Supported on all 7210 SAS platforms as described in this document
This command adds a FEC to the LDP prefix database with a specific label operation on the node.
Permitted operations are swap to originate a FEC for which the LSR is not egress or pop to originate a FEC for which the LSR is egress.
The next-hop, advertised-label, and swap-label keywords are optional. If next-hop is configured but no out-label is specified, a swap occurs with label 3, such as, pop and forward to the next hop. If the next-hop and swap-label are configured, a regular swap occurs. If no parameters are specified, a pop and route is performed.
Specifies the information for the IP prefix and mask length.
Keyword to specify the IP address of the next hop of the prefix.
Keyword to specify the label advertised to the upstream peer. If not configured, the label advertised should be from the label pool. If the configured static label is not available, the IP prefix is not advertised.
Specifies the number of labels to send to the peer associated with this FEC. If configured, the LSR should swap the label with the configured swap-label. If not configured, the default action is pop if the next-hop parameter is not defined.
Specifies the number of labels to send to the peer associated with this FEC.
Keyword to specify to pop the label and transmit without the label.
Specifies the name of the interface that the label for the originated FEC is swapped to. For an unnumbered interface, this parameter is mandatory because there is no address for the next hop. For a numbered interface, it is optional.
[no] graceful-restart
config>router>ldp
Supported on all 7210 SAS platforms as described in this document
This command enables graceful restart helper.
The no form of this command disables graceful restart.
no graceful-restart
[no] implicit-null-label
config>router>ldp
Supported on all 7210 SAS platforms as described in this document
This command enables the implicit null label. Use this command to signal the IMPLICIT NULL option for all LDP FECs for which this node is the egress LER.
The no form of this command disables the signaling of the implicit null label.
no implicit-null-label
maximum-recovery-time interval
no maximum-recovery-time
config>router>ldp>graceful-restart
Supported on all 7210 SAS platforms as described in this document
This command configures the local maximum recovery time.
The no form of this command reverts to the default value.
120
Specifies the length of time, in seconds.
neighbor-liveness-time interval
no neighbor-liveness-time
config>router>ldp>graceful-restart
Supported on all 7210 SAS platforms as described in this document
This command configures the neighbor liveness time.
The no form of this command reverts to the default value.
120
Specifies the length of time, in seconds.
import policy-name [policy-name … (up to 5 max)]
no import
config>router>ldp
Supported on all 7210 SAS platforms as described in this document
This command configures import route policies to determine which label bindings (FECs) are accepted from LDP neighbors. Policies are configured in the config>router>policy-options context.
If no import policy is specified, LDP accepts all label bindings from configured LDP neighbors. Import policies can be used to limit or modify the routes accepted and their corresponding parameters and metrics.
If multiple policy names are specified, the policies are evaluated in the order they are specified. The first policy that matches is applied. If multiple import commands are issued, the last command entered overrides the previous command. A maximum of five policy names can be specified. The specified names must already be defined.
The no form of this command removes all policies from the configuration.
no import
Specifies the import route policy name. Allowed values are any string up to 32 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.
label-withdrawal-delay seconds
config>router>ldp
Supported on all 7210 SAS platforms as described in this document
This command configures the time interval, in seconds, that LDP will delay the withdrawal of the FEC-label binding it distributed to its neighbors when FEC is deactivated. When the timer expires, LDP then sends a label withdrawal for the FEC to all its neighbors. This is applicable only to LDP transport tunnels (IPv4 prefix FECs) and is not applicable to pseudowires (service FECs).
no label-withdrawal-delay
Specifies the time that LDP delays the withdrawal of the FEC-label binding it distributed to its neighbors when FEC is deactivated.
keepalive timeout factor
no keepalive
config>router>ldp>interface-parameters>interface>ipv4
config>router>ldp>interface-parameters>ipv4
config>router>ldp>targ-session>ipv4
config>router>ldp>targ-session>peer
Supported on all 7210 SAS platforms as described in this document
This command configures the time, in seconds, that LDP waits before tearing down the session. The factor parameter is the keepalive interval.
If no LDP messages are exchanged for the configured amount of time, the LDP session is torn down. Keepalive timeout is usually three times the keepalive interval. To maintain the session permanently, regardless of the activity, set the value to zero.
When the LDP session is being set up, the keepalive timeout is negotiated to the lower of the two peers. When a operational value is agreed upon, the keepalive factor derives the value of the keepalive interval. The session needs to be flapped for the new settings to work.
The no form of this command at the interface level sets the timeout and factor to the values defined under the interface-parameters level.
The no form of this command at the peer level sets the timeout and factor to the values defined under the targeted-session level.
The default value is dependent upon the CLI context. Table: Keepalive timeout factor default values lists the keepalive timeout factor default values.
Context |
Timeout |
Factor |
|---|---|---|
config>router>ldp>if-params |
30 |
3 |
config>router>ldp>targ-session |
40 |
4 |
config>router>ldp>if-params>if |
Inherits values from interface-parameters context |
|
config>router>ldp>targ-session>peer |
Inherits values from targeted-session context |
|
Specifies the time, in seconds, that LDP waits before tearing down the session.
Specifies the number of keepalive messages, expressed as a decimal integer, that should be sent on an idle LDP session in the keepalive timeout interval.
local-lsr-id interface-name
no local-lsr-id
config>router>ldp>targeted-session>peer
Supported on all 7210 SAS platforms as described in this document
This command enables the use of the address of a specific interface as the LSR ID for the hello adjacency of a T-LDP session. The interface can be a regular interface or a loopback interface, including the system interface.
By default, a T-LDP session uses the system interface address as the LSR ID; however, the system interface must always be configured on the router or the LDP protocol will not come up on the node. There is no requirement to include the system interface in any routing protocol.
At initial configuration, the T-LDP session remains down while the specified interface is down. LDP does not try to bring it up using the system interface.
If the LSR ID is changed on the fly while the T-LDP session is up, LDP immediately tears down the session and attempts to establish one using the new LSR ID, regardless of the operational state of the new interface.
If the interface used as the LSR ID goes down, the T-LDP session also goes down.
The user-configured LSR ID is used exclusively for extended peer discovery to establish the T-LDP hello adjacency. It is also used as the transport address for the TCP session of the LDP session when it is bootstrapped by the T-LDP hello adjacency. The user-configured LSR ID is, however, not used in basic peer discovery to establish a link-level LDP hello adjacency.
The no form of this command reverts to the default behavior, in which case the system interface address is used as the LSR ID.
no local-lsr-id
Specifies the name of the network IP interface. An interface name cannot be in the form of an IP address. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.
interface-parameters
config>router>ldp
Supported on all 7210 SAS platforms as described in this document
Commands in this context configure LDP interfaces and parameters applied to LDP interfaces.
prefix-ipv4 {enable | disable}
config>router>ldp>interface-params>interface>ipv4>fec-type-capability
Supported on all 7210 SAS platforms as described in this document
This command enables and disables IPv4 prefix FEC capability on the interface.
Keyword to enable IPv4 FEC capability.
Keyword to disable IPv4 FEC capability.
hello timeout factor
no hello
config>router>ldp>interface-parameters>interface>ipv4
config>router>ldp>interface-parameters>ipv4
config>router>ldp>targ-session>ipv4
config>router>ldp>targ-session>peer
Supported on all 7210 SAS platforms as described in this document
This command configures the time interval to wait before declaring a neighbor down. The factor parameter derives the hello interval.
Hold time is local to the system and sent in the hello messages to the neighbor. Hold time cannot be less than three times the hello interval.
When LDP session is being set up, the hold-down time is negotiated to the lower of the two peers. After a operational value is agreed upon, the hello factor is used to derive the value of the hello interval. The session needs to be flapped for the new settings to operate.
The no form of this command at the targeted-session level sets the hello timeout and the hello factor to the default values.
The no form of this command at the peer level sets the hello timeout and the hello factor to the value defined under the targeted-session level.
The default value is dependent upon the CLI context. The following table lists the hello timeout factor default values.
Context |
Timeout |
Factor |
|---|---|---|
config>router>ldp>if-params |
15 |
3 |
config>router>ldp>targ-session |
45 |
3 |
config>router>ldp>if-params>if |
Inherits values from interface-parameters context |
|
config>router>ldp>targ-session>peer |
Inherits values from targeted-session context |
|
Specifies the time interval, in seconds, that LDP waits before declaring a neighbor down.
Specifies the number of keepalive messages that should be sent on an idle LDP session in the hello timeout interval.
hello-reduction {enable factor | disable}
no hello-reduction
config>router>ldp>targ-session>ipv4
Supported on all 7210 SAS platforms as described in this document
This command enables the suppression of periodic targeted hello messages between LDP peers after the targeted LDP session is brought up.
When this feature is enabled, the target hello adjacency is brought up by advertising the hold-time value that the user configured in the hello timeout parameter for the targeted session. The LSR node starts advertising an exponentially increasing hold-time value in the hello message as soon as the targeted LDP session to the peer is up. Each new incremented hold-time value is sent in several hello messages equal to the value of the argument factor (the dampening factor) before the next exponential value is advertised. This functionality provides time for the two peers to settle on the new value. When the hold-time reaches the maximum value of 0xffff (binary 65535), the two peers send hello messages at a frequency of every [(65535-1)/local helloFactor] seconds for the lifetime of the targeted-LDP session; for example, if the local hello factor is three (3), hello messages are sent every 21844 seconds.
The LSR node continues to compute the frequency of sending the hello messages based on the minimum of its local hold-time value and the one advertised by its peer, as in RFC 5036. For the targeted LDP session to suppress the periodic hello messages, both peers must bring their advertised hold-time to the maximum value. If one of the LDP peers does not, the frequency of the hello messages sent by both peers continues to be governed by the smaller of the two hold-time values.
When the user enables the hello-reduction command on the LSR node while the targeted LDP session to the peer is operationally up, the change takes effect immediately. The LSR node starts advertising an exponentially increasing hold-time value in the hello message, starting with the currently configured hold-time value.
When the user disables the hello-reduction command while the targeted LDP session to the peer is operationally up, the change in the hold-time from 0xffff (binary 65535) to the user-configured value for this peer takea effect immediately. The local LSR immediately advertises the user-configured hold-time value and does not wait until the next scheduled time to send a hello to make sure the peer adjusts its local hold timeout value.
In general, any configuration change to the parameters of the T-LDP hello adjacency (modifying the hello adjacency hello timeout or factor, enabling or disabling hello-reduction, or modifying the hello-reduction factor) causes the LSR node to immediately trigger an updated hello message with the updated hold-time value without waiting for the next scheduled time to send a hello.
The no form of this command disables hello reduction.
no hello-reduction
Keyword that disables hello reduction.
Specifies the hello-reduction dampening factor.
[no] interface ip-int-name
config>router>ldp>if-params
Supported on all 7210 SAS platforms as described in this document
This command enables LDP on the specified IP interface. The LDP interface must be disabled using the shutdown command before it can be deleted.
The no form of this command deletes the LDP interface and all configuration information associated with the LDP interface.
Specifies the name of an existing interface. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.
bfd-enable
no bfd-enable
config>router>ldp>interface-parameters>interface
Supported on all 7210 SAS platforms as described in this document
This command enables tracking of the hello adjacency to an LDP peer using BFD.
When this command is enabled on an LDP interface, LDP registers with BFD and starts tracking the LSR ID of all peers it formed hello adjacencies with over that LDP interface. The LDP hello mechanism determines the remote address to be used for the BFD session. The parameters used for the BFD session, that is, transmit-interval, receive-interval, and multiplier, are those configured under the IP interface in the config router interface bfd command.
When multiple links exist to the same LDP peer, a hello adjacency is established over each link and a separate BFD session is enabled on each LDP interface. If a BFD session times out on a specific link, LDP immediately associates the LDP session with one of the remaining hello adjacencies and triggers the LDP FRR procedures. As soon as the last hello adjacency goes down because of BFD timing out, the LDP session goes down and the LDP FRR procedures are triggered.
For more information about the list of protocols that support BFD, see 7210 SAS-D, Dxp, K 2F1C2T, K 2F6C4T, K 3SFP+ 8C Router Configuration Guide.
The no form of this command disables BFD on the LDP interface.
no bfd-enable
ipv4
config>router>ldp>interface-parameters>interface
config>router>ldp>interface-parameters
config>router>ldp>targeted-session
Supported on all 7210 SAS platforms as described in this document
Commands in this context configure IPv4 LDP parameters for the interface.
transport-address {interface | system}
no transport-address
config>router>ldp>interface-parameters>interface>ipv4
config>router>ldp>interface-parameters>ipv4
Supported on all 7210 SAS platforms as described in this document
This command configures the transport address used when setting up LDP TCP sessions. The transport address can be configured as interface or system. The transport address can be configured globally (applies to all LDP interfaces) or per interface. The most specific value is used.
With the transport-address command, users set up the LDP interface to the connection that can be set to the interface address or system address. However, there can be an issue of which address to use when there are parallel adjacencies. This address selection situation can also occur when there is a link and a targeted adjacency, because targeted adjacencies request the session to be set up only to the system IP address.
The transport-address value should not be interface if multiple interfaces exist between two LDP neighbors.
Depending on the first adjacency formed, the TCP endpoint is chosen. If one LDP interface is set up as transport-address interface and another as transport-address system, depending on which adjacency was set up first, the TCP endpoint addresses are determined. After that, because the hello contains the LSR ID, the LDP session can be checked to verify that it is set up and then the adjacency can be matched to the session.
For any specific ILDP interface, as the local-lsr-id parameters is changed to interface, the transport-address configuration loses effectiveness, because it is ignored and the ILDP session always uses the relevant interface IP address as the transport address even though system is chosen.
The no form of this command at the global level reverts the transport address to the default value.
The no form of this command at the interface level sets the transport address to the value defined under the global level.
system
Keyword to specify the IP interface address is used to set up the LDP session between neighbors. The transport address interface cannot be used if multiple interfaces exist between two neighbors, because only one LDP session is set up between two neighbors.
Keyword to specify the system IP address is used to set up the LDP session between neighbors.