Troubleshooting
This section describes how to troubleshoot some issues when configuring or using Flowlink.
Flowlink not Receiving Data
Make sure iptables is turned Off on Flowlink, or make sure iptables is not blocking the ports that Flowlink is listening on.
Use
netstat -a
to make sure Flowlink is listening on the correct ports.
Note
netstat has a bug, which shows that applications are only listening with IPv6 on listed ports, when they are actually listening on those ports with IPv4.
Unable to Ping or TCPdump on the F5 Self-IP Interface
SSH to F5 as an administrator.
List the interfaces to see the interface names.
admin@(ip-10-1-1-197)(cfg-sync Standalone)(Active)(/Common)(tmos)# show net interface ---------------------------------------------------------------- Net::Interface Name Status Bits Bits Pkts Pkts Drops Errs Media In Out In Out ---------------------------------------------------------------- 1.1 up 1.3G 1.1G 2.6M 2.6M 0 0 none 1.2 up 177.7M 301.4M 298.9K 310.4K 0 0 none mgmt up 310.9G 876.6G 298.8M 325.5M 0 0 none
Run TCPdump to listen for traffic between Self-IP interface and flow collector IP.
Generate traffic while the TCPdump is running by either opening another SSH session and doing PING test or by sending normal traffic through the virtual server. If you turned on health monitoring with gateway_icmp enabled from the Create a Pool for Flow Collector section, then F5 should already generate ICMP traffic.
The example shown below uses interface name 1.2 with flow collector IP 13.56.210.22. Health monitoring with gateway_icmp is enabled.
admin@(ip-10-1-1-197)(cfg-sync Standalone)(Active)(/Common)(tmos)# tcpdump -ni 1.2 host 13.56.210.22 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on 1.2, link-type EN10MB (Ethernet), capture size 65535 bytes 09:08:47.855318 IP 10.1.3.223 > 13.56.210.22: ICMP echo request, id 54351, seq 37906, length 20 out slot1/tmm3 lis= 09:08:47.857694 IP 13.56.210.22 > 10.1.3.223: ICMP echo reply, id 54351, seq 37906, length 20 in slot1/tmm3 lis= 09:08:52.864852 IP 10.1.3.223 > 13.56.210.22: ICMP echo request, id 54354, seq 37906, length 20 out slot1/tmm2 lis= 09:08:52.867091 IP 13.56.210.22 > 10.1.3.223: ICMP echo reply, id 54354, seq 37906, length 20 in slot1/tmm2 lis=
Network Connectivity
The flow to test network connectivity is:
Network device > Flowlink
Flowlink > PCE
TCPdump
To use TCPdump:
Run on a network device to verify flow records are sent out.
Run on Flowlink to verify flow records are coming in.
Debug Option
Flowlink has a debug option that displays:
Incoming flow records
IP, port, and protocol recorded for flow records
Each time flows are aggregated and uploaded to the PCE
PCE response code to
POST
To debug Flowlink in the session, add the --debug
flag to your Flowlink command.
Example with the debug option enabled:
CONFIG_FILE=/home/employee/config.yaml.netflow /usr/local/bin/illumio/flowlink --debug
Important
Using the debug flag, generates a large amount of data to the console. Enable this option only if needed.