SPAN Configuration and verification on Cisco Nexus 7000
In this post, we will go briefly into the configuration of the SPAN feature on the Nexus 7K switch.
SPAN for ethernet ports monitors all traffic for the source port, which sends a copy of the traffic to a destination port. The network analyzer, which is attached to the destination port, analyzes the traffic that passes through the source port.
A Source port can be a single port or multiple ports or a VLAN, which is also called a monitored port. You can monitor:
- All the packets for the source port which is received (ingress, Rx).
- Transmitted (egress, tx)
- Bidirectional (both).
A replication of the packets from the SPAN source is sent to the SPAN destination port for analysis.
For VLAN-based SPAN (VSPAN), all ports in VLAN are source ports. So the traffic in the VLAN is monitored. You can apply VLAN based filter on the trunk port of the switch to limit the SPAN traffic monitor.
SPAN Configuration on Nexus 7000 series switches
Actually, In order to configure Switched Port Analyzer (SPAN) on Nexus 7000 switches, 2 steps need to be done:
Step 1: Configure the destination interface as “Swichport monitor”:
interface Ethernet1/10 description ### TO_Sniffer_Device ### switchport switchport monitor no shutdown exit
Step 2: Configure the SPAN session:
- Interface as SPAN source:
monitor session 1 description ### SPAN_uplinks_Traffic ### source interface ethernet 1/1 both destination interface ethernet 1/10 no shut exit copy running-config startup-config
- VLANs as SPAN source:
monitor session 1 description ### SPAN_uplinks_Traffic ### source vlan 10, 40-50 both destination interface ethernet 1/10 no shut exit copy running-config startup-config
SPAN verification on Nexus 7000 series switches
- Show monitor:
N7K-1#show monitor Session State Reason Description ------- ----------- ---------------------- -------------------------------- 1 up The session is up
N7K-1#show monitor session all session 1 --------------- type : local state : up source intf : rx : Eth1/1 tx : Eth1/1 both : Eth1/1 source VLANs : rx : tx : both : filter VLANs : filter not specified destination ports : Eth1/10