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Forum Discussion

Antonio3's avatar
Antonio3
Icon for Altocumulus rankAltocumulus
Jul 14, 2025

Block ipv6

Hi, From the anti-bot profile logs, I noticed requests from an IPv6 client IP. I applied this iRules to the VIP to see what was happening.   when FLOW_INIT {   if { [IP::version] eq "6" } {    ...
security
VGF5's avatar
VGF5
Icon for Cumulonimbus rankCumulonimbus
Jul 14, 2025

Hi Antonio3​ 

If your syslog configuration (in bigip.conf) only includes “warning” or higher severity for the local0 facility, informational messages will be filtered and not written to the log file. By default, iRule log messages use the “informational” severity level. 

Option 1: Follow the steps in the following article and update.

K000139985: iRule local0 logs aren't appearing in /var/log/ltm or syslog

Option 2: Increase the log level in your iRule to "warning" so it matches your current filter

log local0.warning "Blocked IPv6 connection from [IP::client_addr]"