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vRouter Command Line Utilities

Overview

This section describes the shell prompt utilities available for examining the state of the vrouter kernel module in Contrail.

The most useful commands for inspecting the Contrail vrouter module are summarized in the following table.

Command	Description
vif	Inspect vrouter interfaces associated with the vrouter module.
flow	Display active flows in a system.
vrfstats	Display next hop statistics for a particular VRF.
rt	Display routes in a VRF.
dropstats	Inspect packet drop counters in the vrouter.
mpls	Display the input label map programmed into the vrouter.
mirror	Display the mirror table entries.
vxlan	Display the vxlan table entries.
nh	Display the next hops that the vrouter knows.
--help	Display all command options available for the current command.

The following sections describe each of the vrouter utilities in detail.

vif Command

The vrouter requires vrouter interfaces (vif) to forward traffic. Use the vif command to see the interfaces that are known by the vrouter.

Note: Having interfaces only in the OS (Linux) is not sufficient for forwarding. The relevant interfaces must be added to vrouter. Typically, the set up of interfaces is handled by components like nova-compute or vrouter agent.

Example: vif --list

# vif –-list  
vif0/0  OS: pkt0
          Type:Agent HWaddr:00:00:5e:00:01:00 IPaddr:0
          Vrf:65535 Flags:L3 MTU:1514 Ref:2
          RX packets:6591  bytes:648577 errors:0
          TX packets:12150  bytes:1974451 errors:0
vif0/1  OS: vhost0
          Type:Host HWaddr:00:25:90:c3:08:68 IPaddr:0
          Vrf:0 Flags:L3 MTU:1514 Ref:3
          RX packets:3446598  bytes:4478599344 errors:0
          TX packets:851770  bytes:1337017154 errors:0
vif0/2  OS: p1p0p0 (Speed 1000, Duplex 1)
          Type:Physical HWaddr:00:25:90:c3:08:68 IPaddr:0
          Vrf:0 Flags:L3 MTU:1514 Ref:22
          RX packets:1643238  bytes:1391655366 errors:2812
          TX packets:3523278  bytes:6806058059 errors:0
vif0/18 OS: tap3214fc7e-88
          Type:Virtual HWaddr:00:00:5e:00:01:00 IPaddr:0
          Vrf:13 Flags:PL3L2 MTU:9160 Ref:6
          RX packets:60  bytes:4873 errors:0
          TX packets:21  bytes:2158 errors:0

Table 1: vif Fields

vif Output Field	Description
vif0/X	The vrouter assigned name, where 0 is the router id and X is the index allocated to the interface within the vrouter.
OS: pkt0	The pkt0 (in this case) is the name of the actual OS (Linux) visible interface name. For physical interfaces, the speed and the duplex settings are also displayed.
Type:xxxxx	Type:Virtual HWaddr:00:00:5e:00:01:00 IPaddr:0 The type of interface and its IP address, as defined by vrouter. The values can be different from what is seen in the OS. Types defined by vrouter include: Virtual – Interface of a virtual machine (VM). Physical – Physical interface (NIC) in the system. Host – An interface toward the host. Agent – An interface used to trap packets to the vrouter agent when decisions need to be made for the forwarding path.
Vrf:xxxxx	Vrf:65535 Flags:L3 MTU:1514 Ref:2 The identifier of the vrf to which the interface is assigned, the flags set on the interface, the MTU as understood by vrouter, and a reference count of how many individual entities actually hold reference to the interface (mainly of debugging value). Flag options identify that the following are enabled for the interface: P - Policy L3 - Layer 3 forwarding L2 - Layer 2 bridging X - Cross connect mode, only set on physical and host interfaces, indicating that packets are moved between physical and host directly, with minimal intervention by vrouter. Typically set when the agent is not alive or not in good shape. Mt - Mirroring transmit direction Mr - Mirroring receive direction Tc - Checksum offload on the transmit side. Valid only on the physical interface.
Rx	RX packets:60 bytes:4873 errors:0 Packets received by vrouter from this interface.
Tx	TX packets:21 bytes:2158 errors:0 Packets transmitted out by vrouter on this interface.

vif Options

Use vif –-help to display all options available for the vif command. Following os a brief description of each option.

Note: It is not recommended to use the following options unless you are very experienced with the system utilities.

# vif --help  
Usage: vif [--create <intf_name> --mac <mac>]
                [--add <intf_name> --mac <mac> --vrf <vrf>
                   --type [vhost|agent|physical|virtual][--policy, --mode <mode:x>]]
                [--delete <intf_id>]
                [--get <intf_id>][--kernel]
                [--set <intf_id> --vlan <vlan_id> --vrf <vrf_id>]
                [--list]
                [--help]

Option	Description
--create	Creates a ‘Host’ interface with name <intf_name> and mac <mac> on the host kernel. The ‘vhost0’ interface that you see on Linux is a typical example of invocation of this command.
--add	Adds the existing interfaces in the host OS to vrouter, with type and flag options.
--delete	Deletes the interface from vrouter. The <intf_id> is the vrouter interface id as given by vif0/X, where X is the iID
--get	Displays a specific interface. The <intf_id> is the vrouter interface id, unless the command is appended by the ‘—kernel’ option, in which case the ID can be the kernel ID.
--set	Set working parameters of an interface. The only ones supported are the vlan id and the vrf. The vlan id as understood by vrouter differs from what one typically expects, and is relevant as of now only for interfaces of service instances.
--list	Display all of the interfaces of which the vrouter is aware.
--help	Display all options available for the current command.

flow Command

Use the flow command to display all active flows in a system.

Example: flow -l

Use -l to list everything in the flow table. The -l is the only relevant debugging option.

  # flow –l  
Flow table
   Index        Source:Port                   Destination:Port   Proto(V)
  ------------------------------------------------------------------------------------------------- 
 263484          1.1.1.252:1203            1.1.1.253:0        1 (3)
                    (Action:F, S(nh):91,  Statistics:22/1848)
     379480          1.1.1.253:1203            1.1.1.252:0        1 (3) 
                    (Action:F, S(nh):75,  Statistics:22/1848)

Each record in the flow table listing displays the index of the record, the source ip: source port, the destination ip: destination port, the inet protocol, and the source vrf to which the flow belongs.

Each new flow has to be approved by the vrouter agent. The agent does this by setting actions for each flow. There are three main actions associated with a flow table entry: Forward (‘F’), Drop (‘D’), and Nat (‘N’).

For NAT, there are additional flags indicating the type of NAT to which the flow is subject, including: SNAT (S), DNAT (D), source port translation (Ps), and destination port translation (Pd).

S(nh) indicates the source nexthop index used for the RPF check to validate that the traffic is from a known source. If the packet must go to an ECMP destination, E:X is also displayed, where ‘X’ indicates the destination to be used through the index within the ECMP next hop.

The Statistics field indicates the Packets/Bytes that hit this flow entry.

There is a Mirror Index field if the traffic is mirrored, listing the indices into the mirror table (which can be dumped by using mirror –-dump).

If there is an explicit association between the forward and the reverse flows, as is the case with NAT, you will see a double arrow in each of the records with either side of the arrow displaying the flow index for that direction.

Example: flow -r

Use -r to view all of the flow setup rates.

# flow –r  
New =    2, Flow setup rate =    3 flows/sec, Flow rate =    3 flows/sec, for last  548 ms  
New =    2, Flow setup rate =    3 flows/sec, Flow rate =    3 flows/sec, for last  543 ms  
New =   -2, Flow setup rate =   -3 flows/sec, Flow rate =   -3 flows/sec, for last  541 ms  
New =    2, Flow setup rate =    3 flows/sec, Flow rate =    3 flows/sec, for last  544 ms  
New =   -2, Flow setup rate =   -3 flows/sec, Flow rate =   -3 flows/sec, for last  542 ms

Example: flow --help

Use --help to display all options available for the flow command.

# flow –-help  
Usage:flow [-f flow_index][-d flow_index][-i flow_index]
                        [--mirror=mirror table index]
                        [-l]
   -f <flow_index>	Set forward action for flow at flow_index <flow_index>
  -d <flow_index>	Set drop action for flow at flow_index <flow_index>
  -i <flow_index>		Invalidate flow at flow_index <flow_index>
  --mirror               	mirror index to mirror to
  -l                         	List  all flows
  -r                        	Start dumping flow setup rate
  --help                 	Print this help

vrfstats Command

Use vrfstats to display statistics per next hop for a vrf. It is typically used to determine if packets are hitting the expected next hop.

Example: vrfstats --dump

The —dump option displays the statistics for all vrfs that have seen traffic. In the following example, there was traffic only in Vrf 0 (the public vrf). Receives shows the number of packets that came in the fabric destined to this location. Encaps shows the number of packets destined to the fabric.

If there is VM traffic going out on the fabric, the respective tunnel counters will increment.

 # vrfstats --dump
  Vrf: 0
  Discards 414, Resolves 3, Receives 165334
  Ecmp Composites 0, L3 Mcast Composites 0, L2 Mcast Composites 0, Fabric Composites 0, Multi Proto Composites 0
  Udp Tunnels 0, Udp Mpls Tunnels 0, Gre Mpls Tunnels 0
  L2 Encaps 0, Encaps 130955

Example: vrfstats --get 0

Use --get 0 to retrieve statistics for a particular vrf.

 # vrfstats --get 0
  Vrf: 0
  Discards 418, Resolves 3, Receives 166929
  Ecmp Composites 0, L3 Mcast Composites 0, L2 Mcast Composites 0, Fabric Composites 0, Multi Proto Composites 0
  Udp Tunnels 0, Udp Mpls Tunnels 0, Gre Mpls Tunnels 0
  L2 Encaps 0, Encaps 132179

Example: vrfstats --help

Usage: vrfstats --get <vrf>
                                   --dump
                                   --help

--get <vrf>    		Displays packet statistics for the vrf <vrf>

--dump         	Displays packet statistics for all vrfs

--help           	Displays this help message

rt Command

Use the rt command to display all routes in a vrf.

Example: rt --dump

The following example displays inet family routes for vrf 0.

# rt --dump 0

Kernel IP routing table 0/0/unicast

Destination             PPL        Flags        Label        Nexthop

0.0.0.0/8                0                        -              5

1.0.0.0/8                0                        -              5

2.0.0.0/8                0                        -              5

3.0.0.0/8                0                        -              5

4.0.0.0/8                0                        -              5

5.0.0.0/8                0                        -              5

In this example output, the first line displays the routing table that is being dumped. In 0/0/unicast, the first 0 is for the router id, the next 0 is for the vrf id, and unicast identifies the unicast table. The vrouter maintains separate tables for unicast and multicast routes. By default, if the —table option is not specified, only the unicast table is dumped.

Each record in the table output specifies the destination prefix length, the parent route prefix length from which this route has been expanded, the flags for the route, the MPLS label if the destination is a VM in another location, and the next hop id. To understand the second field “PPL”, it is good to keep in mind that the unicast routing table is internally implemented as an ‘mtrie’.

The Flags field can have two values. L indicates that the label field is valid, and H indicates that vroute should proxy arp for this IP.

The Nexthop field indicates the next hop ID to which the route points.

Example: rt --dump --table mcst

To dump the multicast table, use the —table option with mcst as the argument.

# rt --dump 0 --table mcst

Kernel IP routing table 0/0/multicast

(Src,Group)                                  Nexthop

0.0.0.0,255.255.255.255

dropstats Command

Use the dropstats command to see packet drop counters in vrouter.

Example: dropstats

# dropstats

GARP                        	0

ARP notme           	12904

Invalid ARPs             	0


Invalid IF                  	0

Trap No IF              	0

IF TX Discard           	 0

IF Drop                     	49

IF RX Discard           	0


Flow Unusable        	0

Flow No Memory     	0

Flow Table Full       	0

Flow NAT no rflow    	0

Flow Action Drop     	0

Flow Action Invalid     	0

Flow Invalid Protocol    	0

Flow Queue Limit Exceeded   	0


Discards                    	34

TTL Exceeded                	0      

Mcast Clone Fail            	0

Cloned Original             	0


Invalid NH                  	2

Invalid Label               	0

Invalid Protocol            	0

Rewrite Fail                	0

Invalid Mcast Source     	0


Push Fails                  	0

Pull Fails                  		0

Duplicated                  	0

Head Alloc Fails            	0

Head Space Reserve Fails    	0

PCOW fails                  	0

       Invalid Packet       	0


Misc                        		0

Nowhere to go               	0

Checksum errors         	0

No Fmd                      	0

Ivalid VNID                 	0

Fragment errors           	0

Invalid Source              	0

dropstats ARP Block

GARP packets from VMs are dropped by vrouter, an expected behavior. In the example output, the first counter GARP indicates how many packets were dropped.

ARP requests that are not handled by vrouter are dropped, for example, requests for a system that is not a host. These drops are counted by ARP notme counters.

The Invalid ARPs counter is incremented when the Ethernet protocol is ARP, but the ARP operation was neither a request nor a response.

dropstats Interface Block

Invalid IF counters are incremented normally during transient conditions, and should not be a concern.

Trap No IF counters are incremented when vrouter is not able to find the interface to trap the packets to vrouter agent, and should not happen in a working system.

IF TX Discard and IF RX Discard counters are incremented when vrouter is not in a state to transmit and receive packets, and typically happens when vrouter goes through a reset state or when the module is unloaded.

IF Drop counters indicate packets that are dropped in the interface layer. The increase can typically happen when interface settings are wrong.

dropstats Flow Block

When packets go through flow processing, the first packet in a flow is cached and the vrouter agent is notified so it can take actions on the packet according to the policies configured. If more packets arrive after the first packet but before the agent makes a decision on the first packet, then those new packets are dropped. The dropped packets are tracked by the Flow unusable counter.

The Flow No Memory counter increments when the flow block doesn't have enough memory to perform internal operations.

The Flow Table Full counter increments when the vrouter cannot install a new flow due to lack of available slots. A particular flow can only go in certain slots, and if all those slots are occupied, packets are dropped. It is possible that the flow table is not full, but the counter might increment.

The Flow NAT no rflow counter tracks packets that are dropped when there is no reverse flow associated with a forward flow that had action set as NAT. For NAT, the vrouter needs both forward and reverse flows to be set properly. If they are not set, packets are dropped.

The Flow Action Drop counter tracks packets that are dropped due to policies that prohibit a flow.

The Flow Action Invalid counter usually does not increment in the normal course of time, and can be ignored.

The Flow Invalid Protocol usually does not increment in the normal course of time, and can be ignored.

The Flow Queue Limit Exceeded usually does not increment in the normal course of time, and can be ignored.

dropstats Miscellaneous Operational Block

The Discard counter tracks packets that hit a discard next hop. For various reasons interpreted by the agent and during some transient conditions, a route can point to a discard next hop. When packets hit that route, they are dropped.

The TTL Exceeded counter increments when the MPLS time-to-live goes to zero.

The Mcast Clone Fail happens when the vrouter is not able to replicate a packet for flooding.

The Cloned Original is an internal tracking counter. It is harmless and can be ignored.

The Invalid NH counter tracks the number of packets that hit a next hop that was not in a state to be used (usually in transient conditions) or a next hop that was not expected, or no next hops when there was a next hop expected. Such increments happen rarely, and should not continuously increment.

The Invalid Label counter tracks packets with an MPLS label unusable by vrouter because the value is not in the expected range.

The Invalid Protocol typically increments when the IP header is corrupt.

The Rewrite Fail counter tracks the number of times vrouter was not able to write next hop rewrite data to the packet.

The Invalid Mcast Source tracks the multicast packets that came from an unknown or unexpected source and thus were dropped.

The Invalid Source counter tracks the number of packets that came from an invalid or unexpected source and thus were dropped.

The remaining counters are of value only to developers.

mpls Command

The mpls utility command displays the input label map that has been programmed in the vrouter.

Example: mpls --dump

The —dump command dumps the complete label map. The output is divided into two columns. The first field is the label and the second is the next hop corresponding to the label. When an MPLS packet with the specified label arrives in the vrouter, it uses the next hop corresponding to the label to forward the packet.

# mpls –dump

MPLS Input Label Map



   Label    NextHop

  ----------------------

    16          9

    17          11

You can inspect the operation on nh 9 as follows:

# nh --get 9

Id:009  Type:Encap     Fmly: AF_INET  Flags:Valid, Policy,   Rid:0  Ref_cnt:4

        EncapFmly:0806 Oif:3 Len:14 Data:02 d0 60 aa 50 57 00 25 90 c3 08 69 08 00

The nh output shows that the next hop directs the packet to go out on the interface with index 3 (Oif:3) with the given rewrite data.

To check the index of 3, use the following:

# vif –get 3

vif0/3  OS: tapd060aa50-57

        Type:Virtual HWaddr:00:00:5e:00:01:00 IPaddr:0

        Vrf:1 Flags:PL3L2 MTU:9160 Ref:6

        RX packets:1056  bytes:103471 errors:0

        TX packets:1041  bytes:102372 errors:0

The -get 3 output shows that the index of 3 corresponds to a tap interface that goes to a VM.

You can also dump individual entries in the map using the —get option, as follows:

# mpls –get 16

MPLS Input Label Map



   Label    NextHop

-----------------------

     16         9

Example: mpls -help

# mpls –help

Usage: mpls --dump

           mpls --get <label>

           mpls --help


--dump  Dumps the mpls incoming label map

--get       Dumps the entry corresponding to label <label>
              in the label map

--help     Prints this help message

mirror Command

Use the mirror command to dump the mirror table entries.

Example: Inspect Mirroring

The following example inspects a mirror configuration where traffic is mirrored from network vn1 (1.1.1.0/24) to network vn2 (2.2.2.0/24). A ping is run from 1.1.1.253 to 2.2.2.253, where both IPs are valid VM IPs, then the flow table is listed:

# flow -l

Flow table

Index              Source:Port        Destination:Port    Proto(V)

-------------------------------------------------------------------------

135024               2.2.2.253:1208            1.1.1.253:0        1 (1)

                 (Action:F, S(nh):17,  Statistics:208/17472 Mirror Index : 0)



387324               1.1.1.253:1208            2.2.2.253:0        1 (1)

                  (Action:F, S(nh):8,  Statistics:208/17472 Mirror Index : 0)

In the example output, Mirror Index:0 is listed, it is the index to the mirror table. The mirror table can be dumped with the —dump option, as follows:

# mirror --dump

Mirror Table

Index    NextHop    Flags    References

------------------------------------------------

   0       		18                     3

The mirror table entries point to next hops. In the example, the index 0 points to next hop 18. The References indicate the number of flow entries that point to this entry.

A next hop get operation on ID 18 is performed as follows:

# nh --get 18

Id:018  Type:Tunnel    Fmly: AF_INET  Flags:Valid, Udp,   Rid:0  Ref_cnt:2

        Oif:0 Len:14 Flags Valid, Udp,  Data:00 00 00 00 00 00 00 25 90 c3 08 69 08 00

        Vrf:-1  Sip:192.168.1.10  Dip:250.250.2.253

        Sport:58818 Dport:8099

The nh --get output shows that mirrored packets go to a system with IP 250.250.2.253. The packets are tunneled as a UDP datagram and sent to the destination. Vrf:-1 indicates that a lookup has to be done in the source Vrf for the destination.

You can also get an individual mirror table entry using the —get option, as follows:

# mirror --get 10

Mirror Table

Index    NextHop    Flags    References

-----------------------------------------------

 10    	    1          		            1

Example: mirror --help

# mirror --help

Usage:  mirror --dump

        mirror --get <index>

        mirror --help

--dump  Dumps the mirror table

--get       Dumps the mirror entry corresponding to index <index>

--help     Prints this help message

vxlan Command

The vxlan command can be used to dump the vxlan table. The vxlan table maps a network ID to a next hop, similar to an MPLS table.

If a packet comes with a vxlan header and if the VNID is one of those in the table, the vrouter will use the next hop identified to forward the packet.

Example: vxlan --dump

# vxlan --dump

VXLAN Table

VNID    NextHop

---------------------

  4         16

  5         16

Example: vxlan --get

You can use the —get option to dump a specific entry, as follows:

# vxlan --get 4

VXLAN Table

 VNID    NextHop

----------------------

  4         16

Example: vxlan --help

# vxlan --help

Usage:  vxlan --dump

        vxlan --get <vnid>

        vxlan --help

--dump  Dumps the vxlan table

--get   Dumps the entry corresponding to <vnid>

--help  Prints this help message

nh Command

The nh command enables you to inspect the next hops that are known by the vrouter. Next hops tell the vrouter the next location to send a packet in the path to its final destination. The processing of the packet differs based on the type of the next hop. The next hop types are described in the following table.

Next Hop Type	Description
Receive	Indicates that the packet is destined for itself and the vrouter should perform Layer 4 protocol processing. As an example, all packets destined to the host IP will hit the receive next hop in the default VRF. Similarly, all traffic destined to the VMs hosted by the server and tunneled inside a GRE will hit the receive next hop in the default VRF first, because the outer packet that carries the traffic to the VM is that of the server.
Encap (Interface)	Used only to determine the outgoing interface and the Layer 2 information. As an example, when two VMs on the same server communicate with each other, the routes for each of them point to an encap next hop, because the only information needed is the Layer 2 information to send the packet to the tap interface of the destination VM. A packet destined to a VM hosted on one server from a VM on a different server will also hit an encap next hop, after tunnel processing.
Tunnel	Encapsulates VM traffic in a tunnel and sends it to the server that hosts the destination VM. There are different types of tunnel next hops, based on the type of tunnels used. Vrouter supports two main tunnel types for Layer 3 traffic: MPLSoGRE and MPLSoUDP. For Layer 2 traffic, a VXLAN tunnel is used. A typical tunnel next hop indicates the kind of tunnel, the rewrite information, the outgoing interface, and the source and destination server IPs.
Discard	A catch-all next hop. If there is no route for a destination, the packet hits the discard next hop, which drops the packet.
Resolve	Used by the agent to lazy install Layer 2 rewrite information.
Composite	Groups a set of next hops, called component next hops or sub next hops. Typically used when multi-destination distribution is needed, for example for multicast, ECMP, and so on.
Vxlan	A VXLAN tunnel is used for Layer 2 traffic. A typical tunnel next hop indicates the kind of tunnel, the rewrite information, the outgoing interface, and the source and destination server IPs.

Example: nh --list

Id:000  Type:Drop      Fmly: AF_INET  Flags:Valid,   Rid:0  Ref_cnt:1781

Id:001  Type:Resolve   Fmly: AF_INET  Flags:Valid,   Rid:0  Ref_cnt:244

Id:004  Type:Receive  Fmly: AF_INET  Flags:Valid, Policy,   Rid:0

               Ref_cnt:2 Oif:1

Id:007  Type:Encap     Fmly: AF_INET  Flags:Valid, Multicast,   Rid:0  Ref_cnt:3

        EncapFmly:0806 Oif:3 Len:14 Data:ff ff ff ff ff ff 00 25 90 c4 82 2c 08 00

Id:010  Type:Encap     Fmly:AF_BRIDGE  Flags:Valid, L2,   Rid:0  Ref_cnt:3

        EncapFmly:0000 Oif:3 Len:0 Data:

Id:012  Type:Vxlan Vrf  Fmly: AF_INET  Flags:Valid,   Rid:0  Ref_cnt:2

        Vrf:1

Id:013  Type:Composite  Fmly: AF_INET  Flags:Valid, Fabric,   Rid:0  Ref_cnt:3

        Sub NH(label): 19(1027)

Id:014  Type:Composite  Fmly: AF_INET  Flags:Valid, Multicast, L3,   Rid:0  Ref_cnt:3

        Sub NH(label): 13(0) 7(0)

Id:015  Type:Composite  Fmly:AF_BRIDGE  Flags:Valid, Multicast, L2,   Rid:0  Ref_cnt:3

        Sub NH(label): 13(0) 10(0)

Id:016  Type:Tunnel    Fmly: AF_INET  Flags:Valid, MPLSoGRE,   Rid:0  Ref_cnt:1

        Oif:2 Len:14 Flags Valid, MPLSoGRE,  Data:00 25 90 aa 09 a6 00 25 90 c4 82 2c 08 00

        Vrf:0  Sip:10.204.216.72  Dip:10.204.216.21

Id:019  Type:Tunnel    Fmly: AF_INET  Flags:Valid, MPLSoUDP,   Rid:0  Ref_cnt:7

        Oif:2 Len:14 Flags Valid, MPLSoUDP,  Data:00 25 90 aa 09 a6 00 25 90 c4 82 2c 08 00

        Vrf:0  Sip:10.204.216.72  Dip:10.204.216.21

Id:020  Type:Composite  Fmly:AF_UNSPEC  Flags:Valid, Multi Proto,   Rid:0  Ref_cnt:2

        Sub NH(label): 14(0) 15(0)

Example: nh --get

Use the --get option to display information for a single next hop.

# nh –get 9

Id:009  Type:Encap     Fmly:AF_BRIDGE  Flags:Valid, L2,   Rid:0  Ref_cnt:4

        EncapFmly:0000 Oif:3 Len:0 Data:

Example: nh --help

# nh –help

Usage: nh --list

       nh --get <nh_id>

       nh --help

--list  Lists All Nexthops

--get   <nh_id> Displays nexthop corresponding to <nh_id>

--help  Displays this help message

Modified: 2014-09-18

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