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How to check whether 3750G is performing hardware based multicast switching?

taolei.cn
Level 1
Level 1

Hello, everybody.

We have a Catalyst 3750G-48TS, used for forwarding IPTV multicast steams, with OSPF and PIM-SM running on its vlan interfaces.

According to official introduction, 3750 can perform "hardware-based" IP multicast routing, with "IP Services software" running on it.

But how to verify whether this feature is on, in other words, how can I know 3750 is performing hardware-based multicast switching or not?

I examine the output of "show ip mroute", there is no "H" flag in the outgoing interface flags.

=====================================================================================

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, z - MDT-data group sender,
       Y - Joined MDT-data group, y - Sending to MDT-data group
       V - RD & Vector, v - Vector
Outgoing interface flags: H - Hardware switched, A - Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 225.0.0.17), 3d12h/stopped, RP 10.0.0.9, flags: SPF
  Incoming interface: Vlan106, RPF nbr 10.0.11.226
  Outgoing interface list: Null

(10.0.10.27, 225.0.0.17), 3d12h/00:03:23, flags: FT
  Incoming interface: Vlan20, RPF nbr 0.0.0.0, Registering (data-header)
  Outgoing interface list:
    Vlan106, Forward/Sparse, 3d10h/00:02:23, A

(*, 225.0.0.16), 3d12h/stopped, RP 10.0.0.9, flags: SPF
  Incoming interface: Vlan106, RPF nbr 10.0.11.226
  Outgoing interface list: Null

(10.0.10.25, 225.0.0.16), 3d12h/00:03:23, flags: FT
  Incoming interface: Vlan20, RPF nbr 0.0.0.0, Registering (data-header)
  Outgoing interface list:
    Vlan106, Forward/Sparse, 3d10h/00:03:02

=====================================================================================

The following is the output of  "show version":

=====================================================================================

Cisco IOS Software, C3750 Software (C3750-IPSERVICES-M), Version 12.2(50)SE5, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Tue 28-Sep-10 12:56 by prod_rel_team
Image text-base: 0x01000000, data-base: 0x02C00000

ROM: Bootstrap program is C3750 boot loader
BOOTLDR: C3750 Boot Loader (C3750-HBOOT-M) Version 12.2(44r)SE8, RELEASE SOFTWARE (fc1)

ndt-3750g-1 uptime is 4 weeks, 4 days, 19 hours, 9 minutes
System returned to ROM by power-on
System restarted at 18:15:27 UTC Sun Apr 15 2012
System image file is "flash:/c3750-ipservices-mz.122-50.SE5/c3750-ipservices-mz.122-50.SE5.bin"

cisco WS-C3750G-48TS (PowerPC405) processor (revision K0) with 131072K bytes of memory.
Processor board ID FOC1520X2XP
Last reset from power-on
5 Virtual Ethernet interfaces
52 Gigabit Ethernet interfaces
The password-recovery mechanism is enabled.
         
512K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address       : 08:D0:9F:E2:8C:00
Motherboard assembly number     : 73-10218-10
Power supply part number        : 341-0107-01
Motherboard serial number       : FOC15460EUP
Power supply serial number      : ALD1529C03K
Model revision number           : K0
Motherboard revision number     : A0
Model number                    : WS-C3750G-48TS-S
System serial number            : FOC1520X2XP
Top Assembly Part Number        : 800-26857-05
Top Assembly Revision Number    : F0
Version ID                      : V07
CLEI Code Number                : CMMAB00ARA
Hardware Board Revision Number  : 0x09


Switch Ports Model              SW Version            SW Image                
------ ----- -----              ----------            ----------              
*    1 52    WS-C3750G-48TS     12.2(50)SE5           C3750-IPSERVICES-M      


Configuration register is 0xF

=====================================================================================

6 Replies 6

smehrnia
Level 7
Level 7

hi,

use this command;  show ip pim interface count  if multicast is hardware switched its shown there with the H flag.

OR  show mls ip multicast interface  shows interfaces using multicst Hardware switching.

to enable hardware switching of multicst insert this global config cmnd: mls ip multicast

plz Rate if helped.

Soroush.


Hope it Helps!

Soroush.

Hi, Soroush.

"show ip pim interface count " shows no "H" tag, but "D", which means the switch is performing MDS:

===========================================================

State: * - Fast Switched, D - Distributed Fast Switched

       H - Hardware Switching Enabled

Address          Interface                FS  Mpackets In/Out

10.0.10.3        Vlan20                   D   8305881/17

10.0.11.228      Vlan106                  D   25510/3908970

10.0.11.253      Vlan30                   D   5/0

===========================================================

Is this mean my 3750 switch is not doing hardware-based multicast routing?

But there's no "mls ip multicast" command:

===========================================================

ndt-3750g-1(config)#mls ?
  qos  qos keyword

ndt-3750g-1(config)#mls

===========================================================

I guess you are running PIM version 1, upgrade it to version 2. it should be fine then.

> ip pim version 2

plz Rate if it helped.

Soroush.

Hope it Helps!

Soroush.

Hi, we are running PIM v2.

=======================================================

ndt-3750g-1#sh ip pim int

Address          Interface                Ver/   Nbr    Query  DR     DR
                                          Mode   Count  Intvl  Prior
10.0.10.3        Vlan20                   v2/S   1      1      10     10.0.10.3
10.0.11.228      Vlan106                  v2/S   3      1      10     10.0.11.228
10.0.11.253      Vlan30                   v2/S   1      1      10     10.0.11.253
ndt-3750g-1#

=======================================================

=======================================================

ndt-3750g-1#sh ip int vlan 106

Vlan106 is up, line protocol is up

  Internet address is 10.0.11.228/28

  Broadcast address is 255.255.255.255

  Address determined by setup command

  MTU is 1500 bytes

  Helper address is not set

  Directed broadcast forwarding is disabled

  Multicast reserved groups joined: 224.0.0.1 224.0.0.2 224.0.0.22 224.0.0.13

      224.0.0.5

  Outgoing access list is not set

  Inbound  access list is not set

  Proxy ARP is enabled

  Local Proxy ARP is disabled

  Security level is default

  Split horizon is enabled

  ICMP redirects are always sent

  ICMP unreachables are always sent

  ICMP mask replies are never sent

  IP fast switching is enabled

  IP CEF switching is enabled

  IP CEF switching turbo vector

  IP Null turbo vector

  IP multicast fast switching is enabled

  IP multicast distributed fast switching is enabled

  IP route-cache flags are Fast, CEF

  Router Discovery is disabled

  IP output packet accounting is disabled

  IP access violation accounting is disabled

  TCP/IP header compression is disabled

  RTP/IP header compression is disabled

  Probe proxy name replies are disabled

  Policy routing is disabled

  Network address translation is disabled

  BGP Policy Mapping is disabled

  Input features: MCI Check

  Output features: Check hwidb

  WCCP Redirect outbound is disabled

  WCCP Redirect inbound is disabled

  WCCP Redirect exclude is disabled ndt-3750g-1#sh ip int vlan 106
Vlan106 is up, line protocol is up
  Internet address is 10.0.11.228/28
  Broadcast address is 255.255.255.255
  Address determined by setup command
  MTU is 1500 bytes
  Helper address is not set
  Directed broadcast forwarding is disabled
  Multicast reserved groups joined: 224.0.0.1 224.0.0.2 224.0.0.22 224.0.0.13
      224.0.0.5
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  Local Proxy ARP is disabled
  Security level is default
  Split horizon is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
  ICMP mask replies are never sent
  IP fast switching is enabled
  IP CEF switching is enabled
  IP CEF switching turbo vector
  IP Null turbo vector
  IP multicast fast switching is enabled
  IP multicast distributed fast switching is enabled
  IP route-cache flags are Fast, CEF
  Router Discovery is disabled
  IP output packet accounting is disabled
  IP access violation accounting is disabled
  TCP/IP header compression is disabled
  RTP/IP header compression is disabled
  Probe proxy name replies are disabled
  Policy routing is disabled
  Network address translation is disabled
  BGP Policy Mapping is disabled
  Input features: MCI Check
  Output features: Check hwidb
  WCCP Redirect outbound is disabled
  WCCP Redirect inbound is disabled
  WCCP Redirect exclude is disabled

=======================================================

(10.0.10.27, 225.0.0.17), 3d12h/00:03:23, flags: FT

  Incoming interface: Vlan20, RPF nbr 0.0.0.0, Registering (data-header)

It looks like you are stuck in registering.  Is there an RP defined for these groups? Is that RP allowed to be the RP for these groups? It looks like either the RP isn't getting the pim register message or isn't replying with the register/stop message back to the 3750.

-Matt

Hi, Matt.

The RP is not a Cisco device and always sends register-stop message back to 3750 after some delay (I don't know why). But this is not the problem.

I wonder whether 3750 really supports hardware-based multicast forwarding.

==============================================================

ndt-3750g-1#sh ip mroute
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, z - MDT-data group sender,
       Y - Joined MDT-data group, y - Sending to MDT-data group
       V - RD & Vector, v - Vector
Outgoing interface flags: H - Hardware switched, A - Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 225.0.0.17), 4d09h/stopped, RP 10.0.0.9, flags: SPF
  Incoming interface: Vlan106, RPF nbr 10.0.11.226
  Outgoing interface list: Null

(10.0.10.27, 225.0.0.17), 4d09h/00:03:27, flags: FT
  Incoming interface: Vlan20, RPF nbr 0.0.0.0
  Outgoing interface list:
    Vlan106, Forward/Sparse, 4d07h/00:02:24, A

(*, 225.0.0.16), 4d09h/stopped, RP 10.0.0.9, flags: SPF
  Incoming interface: Vlan106, RPF nbr 10.0.11.226
  Outgoing interface list: Null

(10.0.10.25, 225.0.0.16), 4d09h/00:03:27, flags: FT
  Incoming interface: Vlan20, RPF nbr 0.0.0.0
  Outgoing interface list:
    Vlan106, Forward/Sparse, 4d07h/00:02:59

(*, 225.0.0.19), 4d09h/stopped, RP 10.0.0.9, flags: SPF
  Incoming interface: Vlan106, RPF nbr 10.0.11.226
  Outgoing interface list: Null

(10.0.10.27, 225.0.0.19), 4d09h/00:03:28, flags: FT
  Incoming interface: Vlan20, RPF nbr 0.0.0.0
  Outgoing interface list:
    Vlan106, Forward/Sparse, 4d07h/00:02:23, A

==============================================================

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