Re: Monitoring Port

mvaldez83 · ‎12-05-2012

So here is the deal, I have a server on switch A where port 3 is monitoring traffic for most of the ports on switch A. However I have other users on switch B that needs to have port 3 on switch A monitor as well. Is this possible? I have been reading about rspan but doesnt seem to work.

Switch A:

monitor session 1 source interface fast0/1 - 2

monitor session 1 source interface fast0/4 - 46

monitor session 1 destination interface fast0/3

(this works great for switch A, I need a solution to get switch B to also have some ports sent to port 3 on switch A for monitoring.)

Thanks in advance!

Matt

Abzal · ‎12-05-2012

Hi,

Are these switches separate or connected to each other? On switchA on port f0/3 connected something like server?

If they are serapate switches and on port it's a server you can plug second network card on server and set up monitoring on switchB like on switchA.

If those are connected your option is RSPAN.

http://www.cisco.com/en/US/docs/switches/lan/catalyst3550/software/release/12.1_13_ea1/configuration/guide/swspan.html

Hope it will help.

Best regards,
Abzal

mvaldez83 · ‎12-05-2012

Yes these switches are connected via a trunk port. f0/3 is connected to a server monitoring the traffic. The software doing the monitoring however can only monitor one port at a time. So I need f0/3 to be the destination port for the ports on switch B. I will check out your link and see what that offers, thanks!

mvaldez83 · ‎12-05-2012

Abzal,

Ok what I am getting from this if I am reading this correclty. So on switch B I create an rpsan vlan (lets call its vlan 10) then all of the ports that need the monitoring should be on that vlan(10). then on the destination port on switch A also needs to be a member of that rspan vlan(10). so if that is the case on swtich A i need to make the source ports members of vlan 10 which is the rspan vlan correct?

mahmoodmkl · ‎12-05-2012

Hi,

No u need put any port which is to be monitored in the rspan vlan,RSPAN vlan will be the destination on the switch where the monitored port is available.The traffic from the source port will go into RSPAN vlan all the way upto the switch where u have connected u r snifffer and on this switch u will have source as the RSPAN vlan and the destination will be the port where the sniffer is connected.

Thanks

mvaldez83 · ‎12-05-2012

Mahmoodmkl,

I'm not sure what you are saying. Are you saying that switch A and B need to be configured for RSPAN? What if I did the following:

Switch A

monitor session 1 source interface fast0/1 - 2

monitor session 1 source interface fast0/4 - 46

monitor session 1 destination interface fast0/3 Put all of the

ports on vlan 10 because I made an rspan vlan 10

On switch B

monitor the ports I need will say 1-10

monitor session 1 source interface fast0/1 - 10

monitor session 1 destination remote vlan 10 (as a prerequisite I would have created vlan 10 as a rspan vlan on switch B.)

Switch A

Monitor session 1 destination remote vlan 10

Would this work?

By the way I am working with cisco catalyst 3560 switches.

mahmoodmkl · ‎12-06-2012

Hi,

The below config should work,u need to create the RSPAN vlan on both the switches.

monitor session 1 source interface f0/1-f0/3

monitor session 1 destination remote vlan 10

Then allow VLAN 10 on trunk between switchA and switchB.

On switchA:

monitor session 2 source interface remote vlan 10

monitor session 2 destination interface f0/4

Thanks

Abzal · ‎12-06-2012

Hi,

On switchB you need to create one VLAN for RSPAN. Then allow it on trunk between switchA. This VLAN will transfer all traffic from ports to switchA via trunk. You don't need to assign these ports you intended to monitor on RSPAN VLAN.

monitor session 1 source interface f0/1-f0/3
monitor session 1 destination remote vlan 10

Then allow VLAN 10 on trunk between switchA and switchB.
On switchA:
monitor session 2 source interface remote vlan 10
monitor session 2 destination interface f0/4

Sent from Cisco Technical Support iPhone App

Best regards,
Abzal

mvaldez83 · ‎12-07-2012

Mahmoodmkl and Abzal,

On swtich A the command monitor session 2 source interface remote vlan 10 does not work.

what did work was monitor session 2 source remote vlan 10 will this suffice?

Also why different session numbers? and if the destination port is on switch A seems like the config you guys gave me should be reversed on switch A and B. So you guys obviously know more then I do however I just wanted to make sure I made it clear port 3 on switch A is connected to a server with software monitoring traffic.

mvaldez83 · ‎12-07-2012

Here are the configs i have in place now, Do these seem right to either of you?

Switch A:

Session 2

---------

Type : Remote Destination Session

Source RSPAN VLAN : 10

Destination Ports : Fa0/3

Encapsulation : Native

Ingress : Disabled

Switch B:

Session 1

---------

Type : Remote Source Session

Source Ports :

Both : Fa0/1-40

Dest RSPAN VLAN : 10

mvaldez83 · ‎12-07-2012

Ok with those commands in place I am not getting traffic on the port when I look at the incoming outgoing traffic on the server, so its not capturing data.

Abzal · ‎12-07-2012

Yes, it looks right. On switchA as you know you need to create SPAN session one for local ports second to RSPAN session.

Sent from Cisco Technical Support iPhone App

Best regards,
Abzal

mvaldez83 · ‎12-07-2012

Abzal,

Looks like its correct then? I wonder why its not receiving any traffic then on the server for fa0/3? When I had the below command in before these changes i was at least getting results on switch A

Switch A:

monitor session 1 source interface fast0/1 - 2

monitor session 1 source interface fast0/4 - 46

monitor session 1 destination interface fast0/3

Should those be put back in along with the current config I posted earlier?

Abzal · ‎12-07-2012

Ok, first of all you need to create different VLAN for RSPAN. Second do not configure access ports on this VLAN. Allow it on trunk port between switches.
1. On switchA will be two sessions first that you posted before.
2. Second for RSPAN session.

SwitchA:

monitor session 1 source interface fast0/1 - 2monitor session 1 source interface fast0/4 - 46monitor session 1 destination interface fast0/3

monitor session 2 source remote vlan 10
monitor session 2 destination interface fast0/3

Sent from Cisco Technical Support iPhone App

Best regards,
Abzal

mvaldez83 · ‎12-07-2012

Abzal,

Here is what I have going on:

Switch A rspan vlan:

VLAN Name Status Ports

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

1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4

Fa0/5, Fa0/6, Fa0/7, Fa0/8

Fa0/9, Fa0/10, Fa0/11, Fa0/12

Fa0/13, Fa0/14, Fa0/15, Fa0/16

Fa0/17, Fa0/18, Fa0/19, Fa0/20

Fa0/21, Fa0/22, Fa0/23, Fa0/24

Fa0/25, Fa0/26, Fa0/27, Fa0/28

Fa0/29, Fa0/30, Fa0/31, Fa0/32

Fa0/33, Fa0/34, Fa0/35, Fa0/36

Fa0/37, Fa0/38, Fa0/39, Fa0/40

Fa0/41, Fa0/42, Fa0/43, Fa0/44

Fa0/45, Fa0/46, Gi0/1, Gi0/2

Gi0/3, Gi0/4

2 Sightly active

3 appstack active

4 pbx active

10 remote-span active

1002 fddi-default act/unsup

1003 token-ring-default act/unsup

1004 fddinet-default act/unsup

1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2

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

1 enet 100001 1500 - - - - - 0 0

2 enet 100002 1500 - - - - - 0 0

3 enet 100003 1500 - - - - - 0 0

4 enet 100004 1500 - - - - - 0 0

10 enet 100010 1500 - - - - - 0 0

1002 fddi 101002 1500 - - - - - 0 0

1003 tr 101003 1500 - - - - srb 0 0

1004 fdnet 101004 1500 - - - ieee - 0 0

1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs

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

10

Switch B rspan vlan:

VLAN Name Status Ports

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

1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4

Fa0/5, Fa0/6, Fa0/7, Fa0/8

Fa0/9, Fa0/10, Fa0/11, Fa0/12

Fa0/13, Fa0/14, Fa0/15, Fa0/16

Fa0/17, Fa0/18, Fa0/19, Fa0/20

Fa0/21, Fa0/22, Fa0/23, Fa0/24

Fa0/25, Fa0/26, Fa0/27, Fa0/28

Fa0/29, Fa0/30, Fa0/31, Fa0/32

Fa0/33, Fa0/34, Fa0/35, Fa0/36

Fa0/37, Fa0/38, Fa0/39, Fa0/40

Fa0/41, Fa0/42, Fa0/43, Fa0/44

Fa0/45, Fa0/48, Gi0/1, Gi0/2

Gi0/3, Gi0/4

2 Sightly active

3 appstack active

4 pbx active

10 remote-span active

1002 fddi-default act/unsup

1003 token-ring-default act/unsup

1004 fddinet-default act/unsup

1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2

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

1 enet 100001 1500 - - - - - 0 0

2 enet 100002 1500 - - - - - 0 0

3 enet 100003 1500 - - - - - 0 0

4 enet 100004 1500 - - - - - 0 0

10 enet 100010 1500 - - - - - 0 0

1002 fddi 101002 1500 - - - - - 0 0

1003 tr 101003 1500 - - - - srb 0 0

1004 fdnet 101004 1500 - - - ieee - 0 0

1005 trnet 101005 1500 - - - ibm - 0 0

Remote SPAN VLANs

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

10

Here is switch A and me adding the session 1 monitor destion command.

Sightly1#conf t

Enter configuration commands, one per line. End with CNTL/Z.

Sightly1(config)#monitor session 1 source interface fast0/1 - 2

Sightly1(config)#monitor session 1 source interface fast0/4 - 46

Sightly1(config)#monitor session 1 destination interface fast0/3

% Interface(s) Fa0/3 already configured as monitor destinations in other monitor

And just again the current show monitor command configuration that is on the switches

Switch A

Session 1

---------

Type : Local Session

Source Ports :

Both : Fa0/1-2,Fa0/4-46

Session 2

---------

Type : Remote Destination Session

Source RSPAN VLAN : 10

Destination Ports : Fa0/3

Encapsulation : Native

Ingress : Disabled

Switch B

Session 1

---------

Type : Remote Source Session

Source Ports :

Both : Fa0/1-40

Dest RSPAN VLAN : 10