What am I doing wrong...................???

Hi All,

I'm attempting to test a very simple iRule - basically extracting the incoming destination TCP port and then matching the extracted port to a number of "IF /ELSE IF" statements for a match in order for re-direction to a specific node /TCP port combination - if no matches found then reject:

when HTTP_REQUEST { 

  set dport [TCP::local_port clientside]

  log local0. "Extract TCP port: $dport"

  if { ($dport > 5000) and ($dport < 5150) } {

    set newlastoctet [ expr $dport - 4900]

    log local0. "IP 4th Octet: $newlastoctet"

    log local0. "10.100.10.$newlastoctet 443"

node 10.100.10.$newlastoctet 443

} elseif { ($dport == 6000) } {

    log local0. "Test point 1: $dport"

    node 10.200.50.1 443

  } elseif { ($dport == 7000) } {

    log local0. "Test point 2: $dport"

node 10.200.20.1 443

  } elseif { ($dport == 8000) } {

   log local0. "Test point 3: $dport"

node 10.200.30.1 443

  } elseif { ($dport == 9000) } {

   log local0. "Test point 4: $dport" 

node 10.200.40.1 443

  } 

  else {

reject}

log local0. "Reject HTTP"

}

Executing the script:

###############

1) HTTP:// (VIP IP):5100:

#################

The log files displays:

Tue Oct 22 14:10:25 AEDT 2019 info ddltf5201 tmm3[15275]   Rule /Common/Test_irule <HTTP_REQUEST>: Extract TCP port: 5100  

Tue Oct 22 14:10:25 AEDT 2019 info ddltf5201 tmm3[15275]   Rule /Common/Test_irule <HTTP_REQUEST>: IP 4th Octet: 200  

Tue Oct 22 14:10:25 AEDT 2019 info ddltf5201 tmm3[15275]   Rule /Common/Test_irule <HTTP_REQUEST>: 10.100.10.200 443  

Tue Oct 22 14:10:25 AEDT 2019 info ddltf5201 tmm3[15275]   Rule /Common/Test_irule <HTTP_REQUEST>: Reject HTTP  

OK, so that extract the TCP port and is tested against the first "IF" statements.

(Not sure why the "Reject HTTP" is logged??? - is there an "exit" cmd to escape from the irule once a match is found?

2) HTTP://(VIP IP):6000

#################

The log file displays:

Tue Oct 22 14:24:28 AEDT 2019 warning ddltf5201.asx.com.au mcpd[5933] 01071859 Warning generated : /Common/Test_irule:5: warning: [use curly braces to avoid double substitution][$dport]  

Why doesn't it log /print the extracted port?

What exactly does "use curly braces to avoid double substitution" mean? I have tried a number of "syntax" options i.e.

remove the "(" >>> { $dport == 6000 }

replace with "{" >>> { {$dport == 6000} }

I gather I'm doing something basically "stupid" here - but just unable to identify what exactly the issue is?

Any thoughts, pointers & hints would be greatly appreciated.

Thanks in advance.

Cheers

Drew