Any traffic coming to or from the ___ of the Arista is visible when running the tcpdump utility on the Arista.
control plane
tcpdump allows users to instantly analyze important traffic such as ___, as well as any other traffic that is destined for the switch itself.
spanning tree and routing protocols
The Linux ___ command can be used to see the available interfaces in the Linux kernel.
ifconfig
ifconfig: The list of interfaces will reflect each of the physical interfaces on the Arista switch as well as any ___ interfaces.
virtual
Any VLAN which has been assigned an ___ will show up as a VLAN interface.
IP address (SVI)
Filter by VLAN interface
bash tcpdump -i vlan1026
The ‘-v’ and ‘-vv’ flags can be used to provide ___ output.
more detailed
Filter traffic on a specific destination port number
bash tcpdump dst port 22
List all network interfaces available for capture
bash tcpdump -D
By default, tcpdump attempts to resolve IP addresses and port numbers into ___
names
Disable hostname resolution using the __ flag.
-n
Disable hostname AND port name resolution using the __ flag.
-nn
Stop capturing after 10 packets
bash tcpdump -c 10
Filter by IP address (source or destination) using 10.95.65.1
bash tcpdump host 10.95.65.1
Filter traffic by interface po50
bash tcpdump -i po50
Filter traffic by source IP address, using 10.95.65.1
bash tcpdump src 10.95.65.1
Filter traffic by destination IP address, using 10.95.65.1
bash tcpdump dst 10.95.65.1
Filter traffic by protocol (ICMP)
bash tcpdump icmp
Filter traffic to or from host 10.95.65.1 of type ICMP. Disable name/port resolution and limit capture to 5 packets.
bash tcpdump -nnc5 host 10.95.65.1 and icmp
Filter SSH traffic destined to host 10.95.65.1
bash tcpdump dst 10.95.65.1 and port 22
How do I see LLDP packets coming from an interface?
bash tcpdump -i et1 ether dst host 01:80:c2:00:00:0e
My server is port-channeled to my Arista switch, and it is not coming up. How do I capture LACP packets coming to and from the server to form the port-channel?
bash tcpdump -nevvi et1 ether host 01:80:c2:00:00:02
bash tcpdump -i et4_22_1 ether host 01:80:c2:00:00:0e ... or bash tcpdump -i et4_22_1 ether proto 0x88cc
LLDP well-known multicast MAC address
LACP well-known multicast MAC address
01:80:c2:00:00:02
bash tcpdump -i et4_22_1 ether host 01:80:c2:00:00:02 ... or bash tcpdump -i et4_22_1 ether proto 0x8809)
Filter SSL traffic to/from IP 10.95.65.1 on Management0. Write the capture to test.pcap on flash.
bash tcpdump -nni ma0 host 10.95.65.1 and port 22 -w flash:test.pcap
Read the first packet from test.pcap in Flash. Disable IP and port name resolution.
bash tcpdump -nnc1 -r flash:test.pcap
How do I capture OSPF packets between neighbors?
bash tcpdump -nnevi po50 proto ospf
Listen on all interfaces just to see if you're seeing any traffic.
-i any
Increase the amount of packet information you get back.
-v, -vv, -vvv
Show the packet’s contents in both hex and ASCII.
-X
Same as -X, but also shows the ethernet header.
-XX
Only get x number of packets and then stop.
-c
Print absolute sequence numbers.
-S
Show minimal protocol information.
-q
Filtering for a specific host with VLAN tags
bash tcpdump -i ma0 vlan and host 10.95.65.1
Filtering for either arp or icmp without VLAN tags
bash tcpdump -i ma0 arp or icmp
Filtering for either arp or icmp with VLAN tags
bash tcpdump -i ma0 vlan and '(arp or icmp)'
Filtering for either arp or icmp with or without VLAN tags
bash tcpdump -i ma0 '(arp or icmp) or (vlan and (arp or icmp))'
The ‘vlan’ keyword in a tcpdump filter changes the lookup offsets for all other keywords ___ the keyword. This behavior is irrespective of parentheses.
following
Filter for BPDUs Without VLAN tags i.e. RSTP/MSTP/untagged native VLAN in Rapid PVST
bash tcpdump -i ma0 stp ... or bash tcpdump -i ma0 ether proto 0x42)
Filter for BPDUs With VLAN tags i.e. tagged VLAN BPDUs in Rapid PVST
Print all packets but NOT those from host 00:25:90:32:ec:2a
bash tcpdump -i ma0 not ether src 00:25:90:32:ec:2a
Filter for VXLAN VNI 200
bash tcpdump -i ma0 'port 4789 and udp[8:2] = 0x0800 and udp[11:4] = 200'
Filter for a VXLAN inner destination of MAC 28:99:3a:8f:b1:41
bash tcpdump -i ma0 'port 4789 and udp[8:2] = 0x0800 and udp[16:4] = 0x28993a8f and udp[20:2] = 0xb141'
Filter for a VXLAN inner source MAC of 28:99:3a:8f:ae:a7
bash tcpdump -i ma0 'port 4789 and udp[8:2] = 0x0800 and udp[22:4] = 0x28993a8f and udp[26:2] = 0xaea7'
Filter for a VXLAN iinner source IP of 20.20.20.10
bash tcpdump -i ma0 'port 4789 and udp[8:2] = 0x0800 and udp[42:4] = 0x1414140a'
Filter for a VXLAN inner destination IP of 20.20.20.5
bash tcpdump -i ma0 'port 4789 and udp[8:2] = 0x0800 and udp[46:4] = 0x14141405'
we can punt traffic to CPU to take captures. It will ___ the CPU as policies rate limiting traffic to CPU are in place (about 1Gb/s)
not overwhelm
LACP packets must be viewed on ___, not the port-channel!
physical interfaces
Filtered Mirroring ___: Configure an ACL with entries that match traffic we are interested in (TX, RX, or both) ending with "mirror session <session name>"
Step 1
Filtered Mirroring ___: Set the last ACL rule as permit ip any any (If the interface doesn’t already have an ACL)
Step 2
Filtered Mirroring ___: Assign the ACL to the interface we would like to capture traffic on
Step 3
Filtered Mirroring ___: Add a destination monitor session port Ethernet, Port-channel, CPU or Tunnel
Step 4
Filtered Mirroring: Associate ACL entries with a monitor session using the key words ___
mirror session
Print traffic from the monitor session pictured. Filter traffic to/from host 10.95.65.1. Disable host name and port name resolutions.
bash tcpdump -nni mirror0 host 10.95.65.1
Configure the switch to automatically send sampled LANZ traffic to the CPU
queue-monitor length mirror destination cpu
Enable LANZ
queue-monitor length
Configure the switch to enable packet sampling of LANZ traffic
queue-monitor length mirror
This command configures a port mirroring session to truncate mirrored packets, retaining only the first 128-192 bytes.
monitor session truncate
Packet truncation can be used to prevent ___ of a monitor session’s destination port. It helps control the utilization of the Mirror CoPP.
oversubscription
packet ___ applies to the mirroring session as a whole, and cannot be applied to individual source ports.
truncation
On Sand, the size of truncated packets can be set to either ___ or ___ bytes.
128, 192
On Strata/Alta, the number of bytes to be retained when truncating packets is fixed at ___
160