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Forum Discussion

Leo_Rodrigues_1's avatar
Leo_Rodrigues_1
Icon for Altocumulus rankAltocumulus
Jun 22, 2015

Sporadic TCL errors from iRule showing up in logs

Hello! I noticed a few errors are showing up on /var/log/ltm. To be able to further debug it, I added a log statement to the script. It then became evident that the log message comes up only ~10% o...
application delivery
deployment
devops
iRules
LTM
StephanManthey's avatar
StephanManthey
Icon for Nacreous rankNacreous
Jun 24, 2015

Hi Leo,

 

the 
scan
in your code works fine to remove the trailing route domain information.

 

In my sample (tested on TMOS v10.2.4) below I use 
getfield
instead.

 

I´m testing for the variable and validate the IPv4 address before logging it.

 

In case the variable does not exist or 
catch
detects an invalid IPv4 address an error will be logged.

 

set client_ip "[getfield [IP::client_addr] "%" 1]"

if { [info exists client_ip] } {
    if { [catch {IP::addr ${client_ip} mask 255.255.255.255}] } {
        log local0. "error: no valid IPv4 address found (${client_ip})"
    } else {
        log local0. "address found (${client_ip})"
    }
} else {
    log local0. "error: variable \$client_ip does not exist"
}

Regarding the error: I guess the result of the scan may contain white space characters or invalid characters causing the TCL error. My sample code might help to figure out these strings.

 

Thanks,

 

Stephan