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monitor port only see Layer 2 traffic

chinpohpang851
Level 1
Level 1

my source port is a access port with no IP assigned and then i wireshark the dest port I can only see ARP, Broadcast...  I can't see any other traffic passing thru that access port. why? 

10 Replies 10

chinpohpang851
Level 1
Level 1

can't see any TLS, HTTP, HTTPS or any handshake.

It sounds like you haven't configured a SPAN/monitor session in the switch. It would be normal for a regular access port to only see broadcasts or traffic directed to the local MAC address.

balaji.bandi
Hall of Fame
Hall of Fame

post the config and monitor session information

 

try :

 

monitor session 1 dest int gig0/1 both   (change the interface as per requirement)

BB

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chinpohpang851
Level 1
Level 1

session1.JPG

 

Gi1/0/1 is just an layer 2 access port to firewall(gateway) but we can't see session traffic on monitoring port Gi1/0/13.

I want to monitor the traffic out/in to the firewall and to see all kinds of traffic.

Hello

Change the destination port to be a trunk and source from the FW access port vlan

 

Example:.
interface int Gi1/13
description span session 1 for gig0/1
switchport mode trunk

switchport trunk allowed vlan x (firewall vlan)


monitor session 1 source vlan vlan x (firewall vlan)
monitor session 1 destination interface Gi1/13


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

I've made the changes accordingly but my monitoring Palo Tap mode interface still not capturing anything.

balaji.bandi
Hall of Fame
Hall of Fame

how does your config look interface and monitor session

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source int

interface GigabitEthernet1/0/1
description To FW port 4
switchport access vlan 1001
switchport mode access
spanning-tree portfast

 

destination int

interface GigabitEthernet1/0/13
description Palo monitor port
switchport access vlan 1001
switchport mode access
switchport nonegotiate

chinpohpang851
Level 1
Level 1

chinpohpang851
Level 1
Level 1
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