This article explains why the SRX return output is very slow when executing the show command. This timeout is caused by fxp0 being down. After fxp0 returns to up status, this issue is resolved.

Customer observes unusually slow response from the CLI on SRX. Even simple commands such as show version stall for a few seconds. The commit command takes an extremely long time before it responds.

The routing engine CPU usage is not high and the firewall should not be busy. There is no configuration error found.

In /var/log/messages , we can see the following error log display after executing the show command:

This timeout is caused by fxp0 being down. In this situation, SRX ca not connect to the TACACS+ server until timeout. Then, output will be delayed. After fxp0 returns to up status, this issue is resolved.

Customer configures a TACACS+ server for accounting.

system {
    tacplus-server {
        10.8.1.1 {
            timeout 5;
        }
    }
    accounting {
        events [ login change-log interactive-commands ];
        destination {
            tacplus {
                server {
                    1.1.1.1 {
                        port 49;
                        timeout 5;
                    }
                }
            }
        }
    }
}

This TACACS+ server is reached through interface fxp0. But the fxp0 is down.

Physical interface: fxp0, Enabled, Physical link is Down.

This timeout is caused by fxp0 being down. In this situation, SRX cannot connect to the TACACS+ server until timeout. Then, output will be delayed. After fxp0 returns to up status, this issue is resolved.

2020-07-08: Article reviewed for accuracy; no changes required.