Last Modified: Sep 13, 2023
Affected Product(s):
BIG-IP APM
Known Affected Versions:
13.1.3.6, 13.1.4, 13.1.4.1, 13.1.5, 13.1.5.1, 14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4
Fixed In:
15.1.0, 14.1.2.1
Opened: May 10, 2019 Severity: 4-Minor
In some scenarios, the named process cannot bind to IPv6 addresses. This occurs because the dnscached process listens to the wildcard IPv6 address port 53 (i.e., :::53) so it cannot respond to queries sent to IPv6 addresses. Following message is reported in ltm log: err named[16593]: binding TCP socket: address in use.
The named process does not respond to the queries that are sent to IPv6 addresses at port 53.
-- The named and dnscached processes are not running. -- The dnscached process is started first. -- The named process is started later.
1) Stop both named and dnscached process. 2) Edit the startup script for dnscached to start in IPv4-only mode. 2a) On BIG-IP system, open the file /etc/bigstart/startup/dnscached. 2b) Add "-4" to the command line option of dnscached. That's done in "/etc/bigstart/scripts/dnscached" add "-4" so this line: exec /usr/sbin/dnscached -f -t $chroot_home -u named -c /config/named.conf -n 1 Now reads like this: exec /usr/sbin/dnscached -4 -f -t $chroot_home -u named -c /config/named.conf -n 1 3) Restart the processes: bigstart restart named dnscached
The dnscached startup script has been modified to start in IPv4-only mode, so it does not listen on any IPv6 address.