NXOS Troubleshooting

 

 

Packet Capture Tool	When Useful	Comments
SPAN	•External Sniffer is available •Capture many packets (look at traffic rate)	•Local SPAN, ERSPAN and exception SPAN
Distributed Packet Tracer (DPT)	•Don’t have an external sniffer •Looking for a specific packet  and details on how it is  forwarded	•Built on ELAM, makes ELAM customer friendly •Can be distributed to multiple switches from a central  point (future road-map)
ELAM ELAMe - script in 6.2(x)	•Don’t have external sniffer •Looking for a specific packet  and details on how it is  forwarded	•Original ELAM can be tricky to configure •source sys/elame.tcl – 6.2(x) makes it customer friendly
Ethanalyzer	•Capture packets Rx/Tx CPU, no external sniffer needed	•Can be filtered using capture/display filters •Redirected to a file to view in Wireshark

Capture filters	Display filters
ARP - arp	ARP - arp Filter ARP by sender mac: arp.src.hw_mac == <sender mac address> Filter ARP by sender IP:  arp.src.proto_ipv4 == <sender IP>  Filter ARP by target IP:  arp.dst.proto_ipv4== <target IP>
DHCP – udp port 68 udp port 67	DHCP – bootp.option.type == 53  bootp.hw.mac_addr == xxxx.xxxx.xxxx

Switch3 -> NXOSv로 ping

 

NXOSv# ethanalyzer local interface mgmt capture-filter icmp

Capturing on mgmt0
2020-05-10 14:00:30.621267      2.2.2.2 -> 2.2.2.1      ICMP Echo (ping) request
2020-05-10 14:00:30.622090      2.2.2.1 -> 2.2.2.2      ICMP Echo (ping) reply
2020-05-10 14:00:30.624552      2.2.2.2 -> 2.2.2.1      ICMP Echo (ping) request
2020-05-10 14:00:30.625157      2.2.2.1 -> 2.2.2.2      ICMP Echo (ping) reply
2020-05-10 14:00:30.627822      2.2.2.2 -> 2.2.2.1      ICMP Echo (ping) request
2020-05-10 14:00:30.628514      2.2.2.1 -> 2.2.2.2      ICMP Echo (ping) reply
2020-05-10 14:00:30.633114      2.2.2.2 -> 2.2.2.1      ICMP Echo (ping) request
2020-05-10 14:00:30.633910      2.2.2.1 -> 2.2.2.2      ICMP Echo (ping) reply
2020-05-10 14:00:30.636560      2.2.2.2 -> 2.2.2.1      ICMP Echo (ping) request
2020-05-10 14:00:30.637402      2.2.2.1 -> 2.2.2.2      ICMP Echo (ping) reply
10 packets captured