PP0E

PPoE requires certain signals and information to establish, accept, control and terminate the session. The basic signalling is shown below.

A PADI (PPPoE Active Discovery Initiation) broadcast signal is sent by the host to the remote devices.

A PADO (PPPoE Active Discovery Offer) signal is sent by the remote device back to the host.

A PADR (PPPoE Active Discovery Request) unicast signal is sent by the host to the remote device.

A PADS (PPPoE Active Discovery Session-Confirmation) is sent by the remote device back to the host.

A PADT (PPPoE Active Discovery Terminate) signal is sent to terminate a PPPoE session. It is the proper way to terminate a session but is not the actual cause for the termination. The cause may be a simple timeout, a manual request by either end, or an out of spec line condition.

netflow versions

Version 1 (V1) is the original format supported in the initial NetFlow releases.
Version 5 (V5) is an enhancement that adds Border Gateway Protocol (BGP) autonomous system information and flow sequence numbers.
Version 6 (V6) is similar to version 7. This version is not used in the new IOS releases.
Version 7 (V7) is an enhancement that exclusively supports NetFlow with Cisco Catalyst 5000 series switches equipped with a NetFlow feature card (NFFC). V7 is not compatible with Cisco routers.
Version 8 (V8) is an enhancement that adds router-based aggregation schemes.
Version 9 is an enhancement to support different technologies such as Multicast, Internet Protocol Security (IPSec), and Multi Protocol Label Switching (MPLS).
Versions 2, 3 and 4 either were not released.
In Versions 1, 5, 6, and 7, the datagram consists of a header and one or more flow records. The first field of the header contains the version number of the export datagram. Typically, a receiving application that accepts any of the format versions allocates a buffer large enough for the largest possible datagram from any of the format versions and then uses the header to determine how to interpret the datagram. The second field in the header contains the number of records in the datagram and should be used to search through the records.
We recommend that receiving applications perform a sanity check on datagrams to ensure that the datagrams are from a valid NetFlow source. You should first check the size of the datagram to verify that it is at least long enough to contain the version and count fields. You should next verify that the version is valid (1, 5, 6, 7, or 8) and that the number of received bytes is enough for the header and count flow records (using the appropriate version).
Because NetFlow export uses UDP to send export datagrams, it is possible for datagrams to be lost. To determine whether flow export information has been lost, Version 5, 6, 7, and Version 8 headers contain a flow sequence number. The sequence number is equal to the sequence number of the previous datagram plus the number of flows in the previous datagram. After receiving a new datagram, the receiving application can subtract the expected sequence number from the sequence number in the header to derive the number of missed flows.
Datagram format Version 8 offers five router-based aggregation schemes allowing you to summarize export data on the router before the data is exported to the collector. The result is lower bandwidth requirements and reduced platform requirements for NetFlow data collection devices. Router-based aggregation enables on-router aggregation by maintaining one or more extra NetFlow caches with different combinations of fields that determine which traditional flows are grouped together. These extra caches are called aggregation caches. As flows expire from the main flow cache, they are added to each enabled aggregation cache. The normal flow ager process runs on each active aggregation cache the same way it runs on the main cache. On-demand aging is also supported.

When to Select a Particular NetFlow Export Format

Export Format	Select When...
Version 9	You need to export data from various technologies, such as Multicast, DoS, IPv6, and BGP next hop. This format accommodates new NetFlow-supported technologies such as Multicast, MPLS, and BGP next hop. The Version 9 export format supports export from the main cache and from aggregation caches.
Version 8	You need to export data from aggregation caches. The Version 8 export format is available only for export from aggregation caches.
Version 5	You need to export data from the NetFlow main cache, and you are not planning to support new features. Version 5 export format does not support export from aggregation caches.
Version 1	You need to export data to a legacy collection system that requires Version 1 export format. Otherwise, do not use Version 1 export format. Use Version 9 or Version 5 export format.

show ip mroute Field Descriptions

Examples

The following is sample output from the show ip mroute command for a router operating in dense mode. This command displays the contents of the IP multicast routing table for the multicast group named cbone-audio.

Router# show ip mroute cbone-audio

IP Multicast Routing Table

Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, 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, A - Candidate for MSDP Advertisement,

       U - URD, I - Received Source Specific Host Report, Z - Multicast Tunnel,

       Y - Joined MDT-data group, y - Sending to MDT-data group

Timers: Uptime/Expires

Interface state: Interface, Next-Hop, State/Mode

(*, 224.0.255.1), uptime 0:57:31, expires 0:02:59, RP is 224.0.0.0, flags: DC

  Incoming interface: Null, RPF neighbor 224.0.0.0, Dvmrp

  Outgoing interface list:

    Ethernet0, Forward/Dense, 0:57:31/0:02:52

    Tunnel0, Forward/Dense, 0:56:55/0:01:28

(192.168.37.100/32, 224.0.255.1), uptime 20:20:00, expires 0:02:55, flags: C

  Incoming interface: Tunnel0, RPF neighbor 10.20.37.33, Dvmrp

  Outgoing interface list:

    Ethernet0, Forward/Dense, 20:20:00/0:02:52

The following is sample output from the show ip mroute command for a router operating in sparse mode:

Router# show ip mroute

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

Timers: Uptime/Expires

Interface state: Interface, Next-Hop, State/Mode

(*, 224.0.255.3), uptime 5:29:15, RP is 198.92.37.2, flags: SC

  Incoming interface: Tunnel0, RPF neighbor 10.3.35.1, Dvmrp

  Outgoing interface list:

    Ethernet0, Forward/Sparse, 5:29:15/0:02:57

(198.92.46.0/24, 224.0.255.3), uptime 5:29:15, expires 0:02:59, flags: C

  Incoming interface: Tunnel0, RPF neighbor 10.3.35.1

  Outgoing interface list:

    Ethernet0, Forward/Sparse, 5:29:15/0:02:57

The following is sample output from the show ip mroute command with the summary keyword:

Router# show ip mroute summary

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

Timers: Uptime/Expires

Interface state: Interface, Next-Hop, State/Mode

(*, 224.255.255.255), 2d16h/00:02:30, RP 171.69.10.13, flags: SJPC

(*, 224.2.127.253), 00:58:18/00:02:00, RP 171.69.10.13, flags: SJC

(*, 224.1.127.255), 00:58:21/00:02:03, RP 171.69.10.13, flags: SJC

(*, 224.2.127.254), 2d16h/00:00:00, RP 171.69.10.13, flags: SJCL

  (128.9.160.67/32, 224.2.127.254), 00:02:46/00:00:12, flags: CLJT

  (129.48.244.217/32, 224.2.127.254), 00:02:15/00:00:40, flags: CLJT

  (130.207.8.33/32, 224.2.127.254), 00:00:25/00:02:32, flags: CLJT

  (131.243.2.62/32, 224.2.127.254), 00:00:51/00:02:03, flags: CLJT

  (140.173.8.3/32, 224.2.127.254), 00:00:26/00:02:33, flags: CLJT

  (171.69.60.189/32, 224.2.127.254), 00:03:47/00:00:46, flags: CLJT

The following is sample output from the show ip mroute command with the active keyword:

Router# show ip mroute active

Active IP Multicast Sources - sending >= 4 kbps

Group: 224.2.127.254, (sdr.cisco.com)

   Source: 146.137.28.69 (mbone.ipd.anl.gov)

     Rate: 1 pps/4 kbps(1sec), 4 kbps(last 1 secs), 4 kbps(life avg)

Group: 224.2.201.241, ACM 97

   Source: 130.129.52.160 (webcast3-e1.acm97.interop.net)

     Rate: 9 pps/93 kbps(1sec), 145 kbps(last 20 secs), 85 kbps(life avg)

Group: 224.2.207.215, ACM 97

   Source: 130.129.52.160 (webcast3-e1.acm97.interop.net)

     Rate: 3 pps/31 kbps(1sec), 63 kbps(last 19 secs), 65 kbps(life avg)

The following example of the show ip mroute EXEC command is displayed when IP multicast MLS is configured. Note that the "H" indicates hardware switched.

Router# show ip mroute

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, H - Hardware

switched

Timers: Uptime/Expires

(*, 229.10.0.1), 00:04:35/00:02:59, RP 0.0.0.0, flags: DJC

Incoming interface: Null, RPF nbr 0.0.0.0

Outgoing interface list:

         Vlan6, Forward/Dense, 00:00:30/00:02:30

    Vlan5, Forward/Dense, 00:04:35/00:02:30

    Vlan2, Forward/Dense, 00:01:28/00:00:00

(192.0.2.20, 229.10.0.1), 00:04:35/00:02:27, flags: CT

Incoming interface: Vlan2, RPF nbr 0.0.0.0

Outgoing interface list:

    Vlan5, Forward/Dense, 00:03:25/00:00:00, H

    Vlan6, Forward/Dense, 00:00:10/00:00:00, H

Table  describes the significant fields shown in the output.

Table  show ip mroute Field Descriptions
Field	Description
Flags:	Provides information about the entry.
D - Dense	Entry is operating in dense mode.
S - Sparse	Entry is operating in sparse mode.
C - Connected	A member of the multicast group is present on the directly connected interface.
L - Local	The router itself is a member of the multicast group.
P - Pruned	Route has been pruned. The Cisco IOS software keeps this information in case a downstream member wants to join the source.
R - RP-bit set	Indicates that the (S, G) entry is pointing toward the rendezvous point (RP). The RP is typically a prune state along the shared tree for a particular source.
F - Register flag	Indicates that the software is registering for a multicast source.
T - SPT-bit set	Indicates that packets have been received on the shortest path source tree.
H - Hardware switched	Indicates the outgoing interface is hardware switched because IP multicast MLS is enabled.
Timers:	Uptime/Expires.
Interface state:	Indicates the state of the incoming or outgoing interface. •Interface. Indicates the type and number of the interface listed in the incoming or outgoing interface list. •Next-Hop or VCD. "Next-hop" specifies the IP address of the downstream neighbor. "VCD" specifies the virtual circuit descriptor number. "VCD0" means the group is using the static map virtual circuit. •State/Mode. "State" indicates that packets will either be forwarded, pruned, or null on the interface depending on whether there are restrictions due to access lists or a time-to-live (TTL) threshold. "Mode" indicates whether the interface is operating in dense, sparse, or sparse-dense mode
(*, 224.0.255.1) (198.92.37.100/32, 224.0.255.1)	Entry in the IP multicast routing table. The entry consists of the IP address of the source router followed by the IP address of the multicast group. An asterisk (*) in place of the source router indicates all sources. Entries in the first format are referred to as (*, G) or "star comma G" entries. Entries in the second format are referred to as (S, G) or "S comma G" entries. (*, G) entries are used to build (S, G) entries.
uptime	How long (in hours, minutes, and seconds) the entry has been in the IP multicast routing table.
expires	How long (in hours, minutes, and seconds) until the entry will be removed from the IP multicast routing table on the outgoing interface.
RP	Address of the rendezvous point router. For routers and access servers operating in sparse mode, this address is always 0.0.0.0.
flags:	Information about the entry.
Incoming interface:	Expected interface for a multicast packet from the source. If the packet is not received on this interface, it is discarded.
RPF neighbor	IP address of the upstream router to the source. "Tunneling" indicates that this router is sending data to the rendezvous point encapsulated in Register packets. The hexadecimal number in parentheses indicates to which rendezvous point it is registering. Each bit indicates a different rendezvous point if multiple rendezvous points per group are used.
Dvmrp or Mroute	Indicates whether the RPF information is obtained from the DVMRP routing table or the static mroutes configuration.
Outgoing interface list:	Interfaces through which packets will be forwarded. When the ip pim nbma-mode command is enabled on the interface, the IP address of the PIM neighbor is also displayed.
Ethernet0	Name and number of the outgoing interface.
Next hop or VCD	Next hop specifies the IP address of the downstream neighbors. VCD is the virtual circuit descriptor number. VCD0 means the group is using the static-map virtual circuit.
Forward/Dense	Indicates that packets will be forwarded on the interface if there are no restrictions due to access lists or TTL threshold. Following the slash (/) is the mode in which the interface is operating (dense or sparse).
Forward/Sparse	Sparse mode interface is in forward mode.
<time/time>     (uptime/expiration time)	Per interface, how long (in hours, minutes, and seconds) the entry has been in the IP multicast routing table. Following the slash (/) is how long (in hours, minutes, and seconds) until the entry will be removed from the IP multicast routing table.