Table Of Contents
Configuring CEF for PFC2
Understanding How Layer 3 Switching Works
Layer 3 Switching Overview
Understanding Layer 3-Switched Packet Rewrite
Understanding IP Unicast Rewrite
Understanding IPX Unicast Rewrite
Understanding IP Multicast Rewrite
Understanding CEF for PFC2
CEF for PFC2 Overview
Understanding Forwarding Decisions
Understanding the FIB
Understanding the Adjacency Table
Partially and Completely Switched Multicast Flows
CEF for PFC2 Examples
Understanding NetFlow Statistics
NetFlow Statistics Overview
NetFlow Table Entry Aging
Flow Masks
Default CEF for PFC2 Configuration
CEF for PFC2 Configuration Guidelines and Restrictions
Configuring CEF for PFC2
Displaying Layer 3-Switching Entries on the Supervisor Engine
Configuring CEF on the MSFC2
Configuring IP Multicast on the MSFC2
Enabling IP Multicast Routing Globally
Enabling IP PIM on an MSFC2 Interface
Configuring the IP MMLS Global Threshold
Enabling IP MMLS on MSFC Interfaces
Displaying IP Multicast Information
Displaying IP Multicast Information on the MSFC2
Displaying IP Multicast Information on the Supervisor Engine
Configuring NetFlow Statistics
Specifying the NetFlow Table Entry Aging-Time Value
Specifying NetFlow Table IP Entry Fast Aging Time and Packet Threshold Values
Setting the Minimum Statistics Flow Mask
Excluding IP Protocol Entries from the NetFlow Table
Displaying NetFlow Statistics
Clearing NetFlow IP and IPX Statistics
Clearing All NetFlow Statistics
Clearing NetFlow IP Statistics
Clearing NetFlow IPX Statistics
Clearing NetFlow Statistics Totals
Displaying NetFlow Statistics Debug Information
Configuring CEF for PFC2
This chapter describes how to configure Cisco Express Forwarding (CEF) for Policy Feature Card 2 (PFC2). CEF for PFC2 provides IP and Internetwork Packet Exchange (IPX) unicast Layer 3 switching and IP multicast Layer 3 switching for Supervisor Engine 2, PFC2, and Multilayer Switch Feature Card 2 (MSFC2).
Note
For complete information on the syntax and usage information for the supervisor engine commands used in this chapter, refer to the Catalyst 6000 Family Command Reference publication.
This chapter consists of these sections:
•
Understanding How Layer 3 Switching Works
•
Default CEF for PFC2 Configuration
•
CEF for PFC2 Configuration Guidelines and Restrictions
•
Configuring CEF for PFC2
•
Configuring NetFlow Statistics
Note
Supervisor Engine 1 with the PFC1 and the MSFC or MSFC2 provide Layer 3 switching with Multilayer Switching (MLS). See "Configuring MLS," for more information.
Note
To configure the MSFC2 to support MLS on a Catalyst 5000 family switch, refer to the Layer 3 Switching Software Configuration Guide at
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat5000/rel_5_2/layer3/index.htm.
Understanding How Layer 3 Switching Works
These sections describe Layer 3 switching with PFC2:
•
Layer 3 Switching Overview
•
Understanding Layer 3-Switched Packet Rewrite
•
Understanding CEF for PFC2
•
Understanding NetFlow Statistics
Layer 3 Switching Overview
Layer 3 switching allows the switch, instead of a router, to forward IP and IPX unicast traffic and IP multicast traffic between VLANs. Layer 3 switching is implemented in hardware and provides wire-speed interVLAN forwarding on the switch, rather than on the MSFC2. Layer 3 switching requires minimal support from the MSFC2. The MSFC2 routes any traffic that cannot be Layer 3 switched.
Note
Layer 3 switching supports the routing protocols configured on the MSFC2. Layer 3 switching does not replace the routing protocols configured on the MSFC2. Layer 3 switching uses Protocol Independent Multicast (PIM) for multicast route determination.
Layer 3 switching on Catalyst 6000 family switches provides flow statistics that you can use to identify traffic characteristics for administration, planning, and troubleshooting. Layer 3 switching uses NetFlow Data Export (NDE) to export flow statistics (for more information about NDE, see "Configuring NDE").
Note
Traffic is Layer 3 switched after being processed by the VLAN access control list (VACL) feature and the quality of service (QoS) feature.
Understanding Layer 3-Switched Packet Rewrite
When a packet is Layer 3 switched from a source in one VLAN to a destination in another VLAN, the switch performs a packet rewrite at the egress port based on information learned from the MSFC2 so that the packets appear to have been routed by the MSFC2.
Note
Rather than just forwarding IP multicast packets, the PFC2 replicates them as necessary on the appropriate VLANs.
Packet rewrite alters five fields:
•
Layer 2 (MAC) destination address
•
Layer 2 (MAC) source address
•
Layer 3 IP Time to Live (TTL) or IPX Transport Control
•
Layer 3 checksum
•
Layer 2 (MAC) checksum (also called the frame checksum or FCS)
Note
Packets are rewritten with the encapsulation appropriate for the next-hop subnet.
If Source A and Destination B are on different VLANs and Source A sends a packet to the MSFC2 to be routed to Destination B, the switch recognizes that the packet was sent to the Layer 2 (MAC) address of the MSFC2.
To perform Layer 3 switching, the switch rewrites the Layer 2 frame header, changing the Layer 2 destination address to the Layer 2 address of Destination B and the Layer 2 source address to the Layer 2 address of the MSFC2. The Layer 3 addresses remain the same.
In IP unicast and IP multicast traffic, the switch decrements the Layer 3 TTL value by 1 and recomputes the Layer 3 packet checksum. In IPX traffic, the switch increments the Layer 3 Transport Control value by 1 and recomputes the Layer 3 packet checksum. The switch recomputes the Layer 2 frame checksum and forwards (or for multicast packets, replicates as necessary) the rewritten packet to Destination B's VLAN.
These sections describe how the packets are rewritten:
•
Understanding IP Unicast Rewrite
•
Understanding IPX Unicast Rewrite
•
Understanding IP Multicast Rewrite
Understanding IP Unicast Rewrite
Received IP unicast packets are (conceptually) formatted as follows:
Layer 2 Frame Header
|
Layer 3 IP Header
|
Data
|
FCS
|
Destination
|
Source
|
Destination
|
Source
|
TTL
|
Checksum
|
|
|
MSFC2 MAC
|
Source A MAC
|
Destination B IP
|
Source A IP
|
n
|
calculation1
|
After the switch rewrites an IP unicast packet, it is (conceptually) formatted as follows:
Layer 2 Frame Header
|
Layer 3 IP Header
|
Data
|
FCS
|
Destination
|
Source
|
Destination
|
Source
|
TTL
|
Checksum
|
|
|
Destination B MAC
|
MSFC2 MAC
|
Destination B IP
|
Source A IP
|
n-1
|
calculation2
|
Understanding IPX Unicast Rewrite
Received IPX packets are (conceptually) formatted as follows:
Layer 2 Frame Header
|
Layer 3 IPX Header
|
Data
|
FCS
|
Destination
|
Source
|
Checksum/ IPX Length/ Transport Control
|
Destination Net/ Node/ Socket
|
Source Net/ Node/ Socket
|
|
|
MSFC2 MAC
|
Source A MAC
|
n
|
Destination B IPX
|
Source A IPX
|
After the switch rewrites an IPX packet, it is (conceptually) formatted as follows:
Layer 2 Frame Header
|
Layer 3 IPX Header
|
Data
|
FCS
|
Destination
|
Source
|
Checksum/ IPX Length/ Transport Control
|
Destination Net/ Node/ Socket
|
Source Net/ Node/ Socket
|
|
|
Destination B MAC
|
MSFC2 MAC
|
n+1
|
Destination B IPX
|
Source A IPX
|
Understanding IP Multicast Rewrite
Received IP multicast packets are (conceptually) formatted as follows:
Layer 2 Frame Header
|
Layer 3 IP Header
|
Data
|
FCS
|
Destination
|
Source
|
Destination
|
Source
|
TTL
|
Checksum
|
|
|
Group G1 MAC1
|
Source A MAC
|
Group G1 IP
|
Source A IP
|
n
|
calculation1
|
After the switch rewrites an IP multicast packet, it is (conceptually) formatted as follows:
Frame Header
|
IP Header
|
Data
|
FCS
|
Destination
|
Source
|
Destination
|
Source
|
TTL
|
Checksum
|
|
|
Group G1 MAC
|
MSFC2 MAC
|
Group G1 IP
|
Source A IP
|
n-1
|
calculation2
|
Understanding CEF for PFC2
These sections describe CEF for PFC2:
•
CEF for PFC2 Overview
•
Understanding Forwarding Decisions
•
Understanding the FIB
•
Understanding the Adjacency Table
•
Partially and Completely Switched Multicast Flows
•
CEF for PFC2 Examples
CEF for PFC2 Overview
Supervisor Engine 2, PFC2, and MSFC2 provide Layer 3 switching with CEF for PFC2. CEF for PFC2 is permanently enabled on Supervisor Engine 2. Cisco IOS CEF is permanently enabled on the MSFC2 in support of CEF for PFC2.
CEF for PFC2 works with CEF (for unicast traffic) and PIM (for multicast traffic) on the MSFC2 to support IP, IP multicast, and IPX traffic. CEF and PIM on the MSFC2 are enhanced to support CEF for PFC2. CEF for PFC2 generates flow statistics for Layer 3-switched traffic that can be displayed at the CLI or used for NDE.
CEF for PFC2 provides Layer 3 switching for all packets that match a complete forwarding information base (FIB) entry (see the "Understanding the FIB" section). CEF for PFC2 sends all packets that match an incomplete FIB entry (one where the MAC address has not been resolved) to the MSFC2 to be routed until the MSFC2 resolves the MAC address.
Note
CEF for PFC2 sends bridge traffic that is addressed at Layer 2 to the MSFC2 to be processed.
Note
Access control lists (ACLs) and policy-based routing can cause CEF for PFC2 to ignore the FIB when making a forwarding decision (see the "Understanding Forwarding Decisions" section).
Enter the show mls cef command to display a Layer 3 switching summary:
Console> (enable) show mls cef
Total L3 packets switched: 0
Total L3 octets switched: 0
IP load sharing entries: 0
IPX load sharing entries: 0
Understanding Forwarding Decisions
CEF for PFC2 provides Layer 3 switching based on:
•
Entries in the ACL ternary content addressable memory (TCAM) for policy-based routing decisions
•
Entries in the NetFlow table for TCP intercept and reflexive ACL forwarding decisions (see the "Understanding NetFlow Statistics" section)
•
Entries in the FIB and adjacency table for all other forwarding decisions
Enter the show mls entry command to display information about the entries used to make forwarding decisions. CEF for PFC2 makes a forwarding decision for each packet and sends the rewrite information for each packet to the egress port, where the rewrite occurs when the packet is transmitted from the switch.
Understanding the FIB
The FIB resides in a separate TCAM. The adjacency table is stored separately in DRAM. The NetFlow table is stored separately in DRAM. The FIB, the adjacency table, and the NetFlow table do not compete with any other features for storage space.
The FIB is conceptually similar to a routing table. It maintains a mirror image of the forwarding information contained in the unicast and multicast routing tables on the MSFC2. When routing or topology changes occur in the network, the unicast and multicast routing tables on the MSFC2 are updated and those changes are reflected in the FIB. The FIB maintains next-hop address information based on the information in the routing tables on the MSFC2. The FIB supports 256K entries, which includes 16K IP multicast entries. With reverse path forwarding (RPF) check enabled, the number of IP entries doubles.
FIB lookup uses the following criteria:
•
Destination IP address for IP unicast
•
Destination IPX network for IPX unicast
•
Source and destination IP address for IP unicast with RPF check
•
Source and destination IP address for IP multicast with RPF check
Note
Because the FIB mirrors the unicast and multicast routing tables on the MSFC2, any commands on the MSFC2 that change the unicast or multicast routing tables affect the FIB. Forwarding entries cannot be cleared from the Supervisor Engine 2 command-line interface (CLI).
In switches with redundant supervisor engines and MSFC2s, the designated MSFC2 supports the FIB on the active Supervisor Engine 2. The routing protocols on the nondesignated MSFC2 send information to the routing protocols on the designated MSFC2.
Enter the show mls entry cef command to display:
•
Module number of the MSFC that is supporting the FIB
•
FIB entry type (receive, connected, resolved, drop, wildcard, or default)
•
Destination address (IP address or IPX network)
•
Destination mask
•
Next-hop address (IP address or IPX network)
•
Next-hop mask
•
Next-hop load-sharing weight
Understanding the Adjacency Table
For each FIB entry, CEF for PFC2 stores Layer 2 information from the designated MSFC2 for adjacent nodes in the adjacency table. Adjacent nodes are nodes that are directly connected at Layer 2. To forward traffic, CEF for PFC2 selects a route from a FIB entry, which points to an adjacency entry, and uses the Layer 2 header for the adjacent node in the adjacency table entry to rewrite the packet during Layer 3 switching. CEF for PFC2 supports 256K adjacency table entries.
Table 13-1 lists the adjacency types.
Table 13-1 Adjacency Types
Adjacency Type
|
Description
|
connect
|
Entry type that contains complete rewrite information
|
punt
|
Entry to send traffic to the MSFC2
|
no r/w
|
Entry to send traffic to the MSFC2 when rewrite information is incomplete
|
frc drp
|
Entry used to drop packets due to ARP throttling
|
drop, null, loopbk
|
Entries used to drop packets
|
Enter the show mls entry cef adjacency command to display:
•
FIB information (see the "Understanding the FIB" section)
•
Adjacency type (connect, drop, null, loopbk, frc drp, punt, no r/w)
•
Next-hop MAC address
•
Next-hop VLAN
•
Next-hop encapsulation
•
Number of packets transmitted to this adjacency from the associated FIB entry
•
Number of bytes transmitted to this adjacency from the associated FIB entry
Partially and Completely Switched Multicast Flows
Some flows might be partially Layer 3 switched instead of completely Layer 3 switched in these situations:
•
The MSFC is configured as a member of the IP multicast group (using the ip igmp join-group command) on the RPF interface of the multicast source.
•
The MSFC is the first-hop router to the source in PIM sparse mode (in this case, the MSFC must send PIM-register messages to the rendezvous point).
•
The multicast TTL threshold is configured on an egress interface for the flow.
•
The multicast helper is configured on the RPF interface for the flow, and multicast to broadcast translation is required.
•
Multicast tag switching is configured on an egress interface.
•
Network address translation (NAT) is configured on an interface, and source address translation is required for the outgoing interface.
Note
CEF for PFC2 provides Layer 3 switching when the extended access list deny condition on the RPF interface specifies something other than the Layer 3 source, Layer 3 destination, or IP protocol (an example is the Layer 4 port numbers).
For partially switched flows, all multicast traffic belonging to the flow reaches the MSFC and is software switched for any interface that is not Layer 3 switched.
Note
All (*,G) flows are always partially Layer 3 switched.
The PFC prevents multicast traffic in flows that are completely Layer 3 switched from reaching the MSFC, reducing the load on the MSFC. The show ip mroute and show mls ip multicast commands identify completely Layer 3-switched flows with the text string RPF-MFD (Multicast Fast Drop [MFD] indicates that from the viewpoint of the MSFC, the multicast packet is dropped, because it is switched by the PFC).
For all completely Layer 3-switched flows, the PFC periodically sends multicast packet and byte count statistics to the MSFC, because the MSFC cannot record multicast statistics for completely switched flows, which it never sees. The MSFC uses the statistics to update the corresponding multicast routing table entries and reset the appropriate expiration timers.
CEF for PFC2 Examples
Figure 13-1 shows a simple IP CEF network topology. In this example, Host A is on the Sales VLAN (IP subnet 171.59.1.0), Host B is on the Marketing VLAN (IP subnet 171.59.3.0), and Host C is on the Engineering VLAN (IP subnet 171.59.2.0).
When Host A initiates an HTTP file transfer to Host C, the PFC2 uses the information in the FIB and adjacency table to forward packets from Host A to Host C.
Figure 13-1 IP CEF Example Topology
Figure 13-2 shows a simple IPX CEF network topology. In this example, Host A is on the Sales VLAN (IPX address 01.Aa), Host B is on the Marketing VLAN (IPX address 03.Bb), and Host C is on the Engineering VLAN (IPX address 02.Cc).
When Host A initiates a file transfer to Host C, the PFC2 uses the information in the FIB and adjacency table to forward packets from Host A to Host C.
Figure 13-2 IPX CEF Example Topology
Understanding NetFlow Statistics
These sections describe NetFlow statistics:
•
NetFlow Statistics Overview
•
NetFlow Table Entry Aging
•
Flow Masks
NetFlow Statistics Overview
CEF for PFC2 generates flow statistics for Layer 3-switched traffic, which are stored in the NetFlow table. NetFlow statistics can be displayed with show commands and are also available to NetFlow Data Export (NDE).
Note
A NetFlow table with more than 32K entries increases the probability that there will be insufficient room to store statistics. To reduce the number of entries in the NetFlow table, you can exclude specified IP protocols from the statistics (see the "Excluding IP Protocol Entries from the NetFlow Table" section).
NetFlow statistics supports unicast and multicast flows:
•
A unicast flow can be any of the following:
–
Destination only: all traffic to a particular destination
–
Destination-source: all traffic from a particular source to a particular destination
–
Full-flow: all traffic from a particular source to a particular destination that shares the same protocol and transport-layer information
•
A multicast flow is all traffic with the same protocol and transport-layer information from a particular source to the members of a particular destination multicast group.
NetFlow Table Entry Aging
The state and identity of flows are maintained while packet traffic is active; when traffic for a flow ceases, the entry ages out. You can configure the aging time for NetFlow table entries kept in the NetFlow table. If an entry is not used for the specified period of time, the entry ages out and statistics for that flow can be exported to a flow collector application.
Flow Masks
Flow masks determine how NetFlow table entries are created. CEF for PFC2 supports only one flow mask (the most specific one) for all statistics. If CEF for PFC2 detects different flow masks from different MSFCs for which it is performing Layer 3 switching, it changes its flow mask to the most specific flow mask detected.
When the flow mask changes, the entire NetFlow table is purged. When CEF for PFC2 exports cached entries, flow records are created based on the current flow mask. Depending on the current flow mask, some fields in the flow record might not have values. Unsupported fields are filled with a zero (0).
The statistics flow masks are as follows:
•
destination-ip—The least-specific flow mask for IP
•
destination-ipx—The only flow mask for IPX
•
source-destination-ip—For IP
•
source-destination-vlan—For IP multicast
•
full flow—The most-specific flow mask
Enter the show mls statistics entry command to display the contents of the NetFlow table and the current flow mask. Use the keyword options to display information for specific traffic (refer to the Catalyst 6000 Family Command Reference publication for more information).
Default CEF for PFC2 Configuration
Table 13-2 shows the default CEF for PFC2 configuration.
Table 13-2 Default CEF for PFC2 Configuration
Feature
|
Default Value
|
CEF for PFC2 enable state
|
Enabled (cannot be disabled)
|
CEF enable state on MSFC2
|
Enabled (cannot be disabled)
|
Multicast services (IGMP snooping or GMRP)
|
Disabled
|
Multicast routing on MSFC2
|
Disabled globally
|
PIM routing on MSFC2
|
Disabled on all interfaces
|
IP MMLS Threshold
|
Unconfigured—no default value
|
IP MMLS
|
Enabled when multicast routing is enabled and IP PIM is enabled on the interface
|
CEF for PFC2 Configuration Guidelines and Restrictions
Follow these guidelines and restrictions when configuring CEF for PFC2:
•
PFC2 supports a maximum of 16 unique Hot Standby Router Protocol (HSRP) group numbers. You can use the same HSRP group numbers in different VLANs. If you configure more than 16 HSRP groups, this restriction prevents use of the VLAN number as the HSRP group number.
Note
Identically numbered HSRP groups use the same virtual MAC address, which might cause errors if you configure bridging on the MSFC.
•
Because of the restriction to 16 unique HSRP group numbers, CEF for PFC2 cannot support the standby use-bia HSRP command.
•
CEF for PFC2 supports the following ingress and egress encapsulations:
–
For IP unicast:
Ethernet V2.0 (ARPA)
802.3 with 802.2 with 1 byte control (SAP1)
802.3 with 802.2 and SNAP
–
For IPX:
Ethernet V2.0 (ARPA)
802.3 (raw)
802.2 with 1 byte control (SAP1)
SNAP
Note
When the ingress encapsulation for IPX traffic is SAP1, CEF for PFC2 provides Layer 3 switching only when the egress encapsulation is also SAP1. The MSFC2 routes IPX SAP1 traffic that requires an encapsulation change.
–
For IP multicast—Ethernet V2.0 (ARPA)
CEF for PFC2 does not provide Layer 3 switching for an IP multicast flow in the following cases:
•
For IP multicast groups that fall into the range 224.0.0.* (where * is in the range 0-255), which is used by routing protocols. CEF for PFC2 supports 225.0.0.* through 239.0.0.* and 224.128.0.* through 239.128.0.*.
Note
Groups in the 224.0.0.* range are reserved for routing control packets and must be flooded to all forwarding ports of the VLAN. These addresses map to the multicast MAC address range 01-00-5E-00-00-xx, where xx is in the range 0-0xFF.
•
For PIM auto-RP multicast groups (IP multicast group addresses 224.0.1.39 and 224.0.1.40).
Note
In systems with redundant MSFC2s, the PIM interface configuration must be the same on both the active and the redundant MSFC2.
•
If the shortest-path tree (SPT) bit for the flow is cleared when running PIM sparse mode for the interface or group.
•
For fragmented IP packets and packets with IP options. However, packets in the flow that are not fragmented or that do not specify IP options are multilayer switched.
•
For source traffic received on tunnel interfaces (such as MBONE traffic).
•
For any RPF interface with multicast tag switching enabled.
Configuring CEF for PFC2
These sections describe how to configure CEF for PFC2:
•
Displaying Layer 3-Switching Entries on the Supervisor Engine
•
Configuring CEF on the MSFC2
•
Configuring IP Multicast on the MSFC2
•
Displaying IP Multicast Information
Note
For information on configuring routing on the MSFC2, see "Configuring InterVLAN Routing."
Displaying Layer 3-Switching Entries on the Supervisor Engine
CEF for PFC2 is permanently enabled on Supervisor Engine 2 with the PFC2 and the MSFC2. No configuration is required.
To display all the Layer 3-switching entries on the supervisor engine, perform this task:
Task
|
Command
|
Display Layer 3-switching information.
|
show mls entry [cef] | [netflow-route]
|
This example shows how to display the Layer 3-switching entries:
Console> (enable) show mls entry
Mod FIB-Type Destination-IP Destination-Mask NextHop-IP Weight
--- --------- --------------- ---------------- --------------- ------
15 receive 0.0.0.0 255.255.255.255
15 receive 255.255.255.255 255.255.255.255
15 receive 127.0.0.12 255.255.255.255
16 receive 127.0.0.0 255.255.255.255
16 receive 127.255.255.255 255.255.255.255
15 resolved 127.0.0.11 255.255.255.255 127.0.0.11 1
15 receive 21.2.0.4 255.255.255.255
16 receive 21.0.0.0 255.255.255.255
16 receive 21.255.255.255 255.255.255.255
15 receive 44.0.0.1 255.255.255.255
16 receive 44.0.0.0 255.255.255.255
16 receive 44.255.255.255 255.255.255.255
15 receive 42.0.0.1 255.255.255.255
16 receive 42.0.0.0 255.255.255.255
16 receive 42.255.255.255 255.255.255.255
15 receive 43.0.0.99 255.255.255.255
15 receive 43.0.0.0 255.255.255.255
15 receive 43.255.255.255 255.255.255.255
15 receive 192.20.20.20 255.255.255.255
16 receive 21.2.0.5 255.255.255.255
16 receive 42.0.0.20 255.255.255.255
15 connected 43.0.0.0 255.0.0.0
15 drop 224.0.0.0 240.0.0.0
15 wildcard 0.0.0.0 0.0.0.0
Mod FIB-Type Dest-IPX-net NextHop-IPX Weight
--- --------- ------------ ------------------------- ------
15 resolved 450 42.0050.3EA9.ABFD 1
15 resolved 480 42.0050.3EA9.ABFD 1
Destination-IP Source-IP Prot DstPrt SrcPrt Destination-Mac Vlan EDst Stat-Pkts
Stat-Bytes Uptime Age TcpDltSeq TcpDltAck
--------------- --------------- ----- ------ ------ ----------------- ---- ---- ----------
----------- -------- -------- --------- ---------
0.0.0.5 0.0.0.5 5 204 104 cc-cc-cc-cc-cc-cc 5 ARPA 0
0 01:03:18 01:00:51 cccccccc cccccccc
0.0.0.2 0.0.0.2 2 201 101 cc-cc-cc-cc-cc-cc 2 ARPA 0
0 01:03:21 01:00:51 cccccccc cccccccc
0.0.0.4 0.0.0.4 4 203 X cc-cc-cc-cc-cc-cc 4 ARPA 0
0 01:03:19 01:00:51 cccccccc cccccccc
0.0.0.1 0.0.0.1 ICMP 200 100 cc-cc-cc-cc-cc-cc 1 ARPA 0
0 01:03:25 01:00:52 cccccccc cccccccc
0.0.0.3 0.0.0.3 3 202 102 cc-cc-cc-cc-cc-cc 3 ARPA 0
0 01:03:20 01:00:52 cccccccc cccccccc
0.0.0.6 0.0.0.6 TCP 205 105 cc-cc-cc-cc-cc-cc 6 ARPA 0
0 01:03:18 01:00:52 cccccccc cccccccc
Enter the show mls entry cef command to display only the FIB entries. Enter the show mls entry netflow-route command to display only the entries from the TCP intercept feature and reflexive access control lists (ACLs).
Configuring CEF on the MSFC2
CEF is permanently enabled on the MSFC2. No configuration is required to support CEF for PFC2.
Note
The ip load-sharing per-packet, ip cef accounting per-prefix, and ip cef accounting non-recursive IOS CEF commands on the MSFC2 apply only to traffic that is CEF-switched on the MSFC. The commands do not affect traffic that is switched by CEF for PFC2 on the supervisor engine.
Configuring IP Multicast on the MSFC2
These sections describe how to configure the MSFC2 for IP multicast:
•
Enabling IP Multicast Routing Globally
•
Enabling IP PIM on an MSFC2 Interface
•
Configuring the IP MMLS Global Threshold
•
Enabling IP MMLS on MSFC Interfaces
Note
This section describes how to enable IP multicast routing on the MSFC2. For more detailed IP multicast configuration information, refer to the "IP Multicast" section of the Cisco IOS IP and IP Routing Configuration Guide at
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/ip_c/ipcprt3/index.htm
Enabling IP Multicast Routing Globally
You must enable IP multicast routing globally on the MSFC2 before you can enable PIM on MSFC interfaces.
To enable IP multicast routing globally on the MSFC2, perform this task in global configuration mode:
Task
|
Command
|
Enable IP multicast routing globally.
|
Router(config)# ip multicast-routing
|
This example shows how to enable IP multicast routing globally:
Router(config)# ip multicast-routing
Enabling IP PIM on an MSFC2 Interface
You must enable PIM on MSFC2 interfaces before IP multicast will function on those interfaces.
To enable IP PIM on an MSFC2 interface, perform this task in interface configuration mode:
Task
|
Command
|
Enable IP PIM on an MSFC2 interface.
|
Router(config-if)# ip pim {dense-mode | sparse-mode | sparse-dense-mode}
|
This example shows how to enable PIM on an MSFC2 interface using the default mode (sparse-dense-mode):
Router(config-if)# ip pim
This example shows how to enable PIM sparse mode on an MSFC2 interface:
Router(config-if)# ip pim sparse-mode
Configuring the IP MMLS Global Threshold
You can configure a global multicast rate threshold, specified in packets per second, below which all multicast traffic is routed by the MSFC. This prevents creation of MLS entries for short-lived multicast flows, such as join requests.
Note
This command does not affect flows that are already being routed. To apply the threshold to existing routes, clear the route and let it reestablish.
To configure the IP MMLS threshold, perform this task:
Task
|
Command
|
Configure the IP MMLS threshold.
|
Router(config)# [no] mls ip multicast threshold ppsec
|
This example shows how to configure the IP MMLS threshold to 10 packets per second:
Router(config)# mls ip multicast threshold 10
Use the no keyword to deconfigure the threshold.
Enabling IP MMLS on MSFC Interfaces
IP MMLS is enabled by default on the MSFC interface when you enable IP PIM on the interface. Perform this task only if you disabled IP MMLS on the interface and you want to reenable it.
Note
You must enable IP PIM on all participating MSFC interfaces before IP MMLS will function. For information on configuring IP PIM on MSFC interfaces, see the "Enabling IP PIM on an MSFC2 Interface" section.
To enable IP MMLS on an MSFC interface, perform this task:
Task
|
Command
|
Enable IP MMLS on an MSFC interface.
|
Router(config-if)# [no] mls ip multicast
|
This example shows how to enable IP MMLS on an MSFC interface:
Router(config-if)# mls ip multicast
Use the no keyword to disable IP MMLS on an MSFC interface.
Displaying IP Multicast Information
These sections describe how to display IP multicast information:
•
Displaying IP Multicast Information on the MSFC2
•
Displaying IP Multicast Information on the Supervisor Engine
Displaying IP Multicast Information on the MSFC2
These sections describe displaying IP multicast information on the MSFC2:
•
Displaying IP MMLS Interface Information
•
Displaying the IP Multicast Routing Table
•
Displaying IP Multicast Details
•
Using Debug Commands
•
Using Debug Commands on the SCP
Displaying IP MMLS Interface Information
The show ip pim interface count command displays the IP MMLS enable state on MSFC IP PIM interfaces and the number of packets received and sent on the interface.
The show ip interface command displays the IP MMLS enable state on an MSFC interface.
To display IP MMLS information for an IP PIM MSFC interface, perform one of these tasks:
Task
|
Command
|
Display IP MMLS interface information.
|
Router# show ip pim interface [type number] count
|
Display the IP MMLS interface enable state.
|
Router# show ip interface
|
Displaying the IP Multicast Routing Table
The show ip mroute command displays the IP multicast routing table on the MSFC2.
To display the IP multicast routing table, perform this task:
Task
|
Command
|
Display the IP multicast routing table.
|
Router# show ip mroute [group[source]] | [summary] | [count] | [active kbps]
|
This example shows how to display the IP multicast routing table:
Router# show ip mroute 239.252.1.1
IP Multicast Routing Table
Flags:D - Dense, S - Sparse, C - Connected, L - Local, P - Pruned
R - RP-bit set, F - Register flag, T - SPT-bit set, J - Join SPT
M - MSDP created entry, X - Proxy Join Timer Running
Outgoing interface flags:H - Hardware switched
Interface state:Interface, Next-Hop or VCD, State/Mode
(*, 239.252.1.1), 04:04:59/00:02:59, RP 80.0.0.2, flags:SJ
Incoming interface:Vlan800, RPF nbr 80.0.0.2
Vlan10, Forward/Dense, 01:29:57/00:00:00, H
(22.0.0.10, 239.252.1.1), 00:00:19/00:02:41, flags:JT
Incoming interface:Vlan800, RPF nbr 80.0.0.2, RPF-MFD
Vlan10, Forward/Dense, 00:00:19/00:00:00, H
Displaying IP Multicast Details
The show mls ip multicast command displays detailed information about IP MMLS.
To display detailed MMLS information on the MSFC, perform one of these tasks:
Task
|
Command
|
Display IP MMLS group information.
|
Router# show mls ip multicast group group-address [interface type number | statistics]
|
Display IP MMLS details for all interfaces.
|
Router# show mls ip multicast interface type number [statistics | summary]
|
Display a summary of IP MMLS information.
|
Router# show mls ip multicast summary
|
Display IP MMLS statistics.
|
Router# show mls ip multicast statistics
|
Display IP MMLS source information.
|
Router# show mls ip multicast source ip-address [interface type number | statistics]
|
This example shows how to display IP MMLS statistics on the MSFC:
Router# show mls ip multicast statistics
MLS Multicast configuration and state:
Router Mac:0050.0f2d.9bfd, Router IP:1.12.123.234
MLS multicast operating state:ACTIVE
Maximum number of allowed outstanding messages:1
Maximum size reached from feQ:1
Feature Notification sent:5
Feature Notification Ack received:4
Unsolicited Feature Notification received:0
Delete notifications received:1
Flow Statistics messages received:248
MLS Multicast statistics:
Complete flow install Ack:10
Complete flow install Nack:0
Complete flow delete Ack:1
L2 entry not found error:0
LTL entry not found error:0
MET entry not found error:0
L3 entry not found error:0
Complete flow exists error :0
This example shows how to display information on a specific IP MMLS entry on the MSFC:
Router# show mls ip multicast 224.1.1.1
Multicast hardware switched flows:
(1.1.13.1, 224.1.1.1) Incoming interface: Vlan13, Packets switched: 61590
Hardware switched outgoing interfaces: Vlan20 Vlan9
RFD-MFD installed: Vlan13
(1.1.9.3, 224.1.1.1) Incoming interface: Vlan9, Packets switched: 0
Hardware switched outgoing interfaces: Vlan20
(1.1.12.1, 224.1.1.1) Incoming interface: Vlan12, Packets switched: 62010
Hardware switched outgoing interfaces: Vlan20 Vlan9
RFD-MFD installed: Vlan12
(1.1.12.3, 224.1.1.1) Incoming interface: Vlan12, Packets switched: 61980
Hardware switched outgoing interfaces: Vlan20 Vlan9
RFD-MFD installed: Vlan12
(1.1.11.1, 224.1.1.1) Incoming interface: Vlan11, Packets switched: 62430
Hardware switched outgoing interfaces: Vlan20 Vlan9
RFD-MFD installed: Vlan11
(1.1.11.3, 224.1.1.1) Incoming interface: Vlan11, Packets switched: 62430
Hardware switched outgoing interfaces: Vlan20 Vlan9
RFD-MFD installed: Vlan11
Total hardware switched installed: 6
This example shows how to display a summary of IP MMLS information on the MSFC:
Router# show mls ip multicast summary
7 MMLS entries using 560 bytes of memory
Number of partial hardware-switched flows:2
Number of complete hardware-switched flows:5
Using Debug Commands
Table 13-3 describes IP MMLS-related debug troubleshooting commands.
Table 13-3 IP MMLS Debug Commands
Command
|
Description
|
[no] debug mls ip multicast group group_id group_mask
|
Configures filtering that applies to all other multicast debugging commands.
|
[no] debug mls ip multicast events
|
Displays IP MMLS events.
|
[no] debug mls ip multicast errors
|
Turns on debug messages for multicast MLS-related errors.
|
[no] debug mls ip multicast messages
|
Displays IP MMLS messages from/to the hardware switching engine.
|
[no] debug mls ip multicast all
|
Turns on all IP MMLS messages.
|
[no] debug mdss error
|
Turns on MDSS1 error messages.
|
[no] debug mdss events
|
Turns on MDSS-related events.
|
[no] debug mdss all
|
Turns on all MDSS messages.
|
Using Debug Commands on the SCP
Table 13-4 describes the Serial Control Protocol (SCP)-related debug commands to troubleshoot the SCP that runs over the Ethernet out-of-band channel (EOBC).
Table 13-4 SCP Debug Commands
Command
|
Description
|
[no] debug scp async
|
Displays trace for asynchronous data in and out of the SCP system.
|
[no] debug scp data
|
Shows packet data trace.
|
[no] debug scp errors
|
Displays errors and warnings in the SCP.
|
[no] debug scp packets
|
Displays packet data in and out of the SCP system.
|
[no] debug scp timeouts
|
Reports timeouts.
|
[no] debug scp all
|
Turns on all SCP debugging messages |