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2960C switch have limited access after enabling span

hi all,

i having issues with 2960c switch where by my pc get limited access right after i enable span (monitoring) at the switchport. 

i using version 12.2

my sourceport is same vlan and same switch with the destination port

the sourceport is fa0/6

the destination is fa0/8

3 Replies 3

Hello,

with limited access you mean the switch is slow to respond ? SPAN can be hard on the CPU, especially on the lower end switches such as the 2960.

What is the output of 'show proc cpu' ?

devils_advocate
Level 7
Level 7

Is your laptop the one plugged into the SPAN destination port (i.e. Fa0/8)?

If so, a Destination SPAN port will not accept ingress frames from the connected host by default as its designed to receive the SPAN frames only. 

You can use the 'ingress' keyword to tell the port to accept incoming frames:

monitor session session_number destination { interfaceinterface-id [, | -] [ encapsulation replicate] [ ingress {dot1q vlan vlan-id | isl | untagged vlan vlan-id | vlan vlan-id}]}

Specify the SPAN session, the destination port, the packet encapsulation, and the ingress VLAN and encapsulation.

For session_number , specify the session number entered in Step 3.

For interface-id , specify the destination port. The destination interface must be a physical port; it cannot be an EtherChannel, and it cannot be a VLAN.

(Optional) [ , | - ] Specify a series or range of interfaces. Enter a space before and after the comma or hyphen.

(Optional) Enter encapsulation replicate to specify that the destination interface replicates the source interface encapsulation method. If not selected, the default is to send packets in native form (untagged).

Enter ingress with keywords to enable forwarding of incoming traffic on the destination port and to specify the encapsulation type:

  • dot1q vlan vlan-id— Accept incoming packets with IEEE 802.1Q encapsulation with the specified VLAN as the default VLAN.
  • isl  Forward ingress packets with ISL encapsulation.
  • untagged vlan vlan-id or vlan vlan-id— Accept incoming packets with untagged encapsulation type with the specified VLAN as the default VLAN.

thanks for your quick response.

i found out that my wireshark having problem. sorry for the problem.

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