SPAN configuration on 3750

[Pedro Vergara]

Hi all, I'm trying to configure a mirror port on a 3750. This configuration needs to replicate data from local ports, but I need that also act as a regular access port.

With the initial configuration, SPAN port, there is no problem, all the data of the configurated ports is replicating in the configurated port. On the port configurated as mirror there is a PC connected for audio recording. When the port is not operating as SPAN there is communications without problem over the LAN. But when I configure the port as SPAN, communication is interrupted.

Here is the actual configuration:

SWITCH1-PISO7#sh monitor session 1

Session 1

---------

Type                   : Local Session

Source Ports           :

    Both               : Fa1/0/1-7,Fa1/0/9-12,Fa1/0/32-33,Fa1/0/35,Fa1/0/38

Destination Ports      : Fa1/0/47

    Encapsulation      : Native

          Ingress      : Enabled, default VLAN = 215

    Ingress encap : Untagged

SWITCH1-PISO7#sh run int fa1/0/47

Building configuration...

Current configuration : 112 bytes

!

interface FastEthernet1/0/47

switchport access vlan 215

switchport mode access

spanning-tree portfast

end

SWITCH1-PISO7#sh ver

Cisco IOS Software, C3750 Software (C3750-IPSERVICES-M), Version 12.2(50)SE1, RELEASE SOFTWARE (fc2)

****output omitted****

Switch Ports Model              SW Version            SW Image

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

*    1 52    WS-C3750V2-48PS    12.2(50)SE1           C3750-IPSERVICES-M

****output omitted****

I have read on another post (https://supportforums.cisco.com/thread/2059062) that there is a problem with this configuration on this specific platform.

Is this correct?? Does any one have a link on cisco documentation that confirm this? Is there a problem with my configuration??

beforehand thanks for your help

[smehrnia]

Hi,

I havent had experienced it myself, but i've read in a couple or Data Sheets that, C3750 has actually Bidirectional data support on the Switched Port Analyzer (SPAN).

here is a Link:

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps5532/product_data_sheet0900aecd806e27b9.pdf

plz Rate if it helped.

Soroush.

[Ivan Shirshin · Accepted solution]

Hi Pedro,

For the 3750 family, the span destination ingress forwarding  capability's only purpose is to enable ingress traffic forwarding of  frames received on the span destination port from an Intrusion Detection  Systems (IDS) or comparable device. Like a span destination port  without ingress forwarding, MAC address learning is disabled on a span  destination port with ingress forwarding, and a span destination port  with ingress forwarding does not transmit any traffic except that  required for the SPAN session. See the note in the folllwing 3750 guide:

http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_44_se/configuration/guide/swspan.html#wp1210541

So if the port on 3750 is configured as SPAN destination, it cannot act as regular access port.

Kind Regards,
Ivan

**Please grade this post if you find it useful.

[smehrnia]

Nice to know, Thanks!

[Pedro Vergara]

Soroush, thanks for your help.

Ivan, thank you for the information, very helpful.

[Ivan Shirshin]

welcome, Pedro!

Kind Regards,
Ivan