Hi, i'm running CentOS 6.0 on my server and installed mrtg from the rpm-package mrtg-2.16.2 . I also installed the depending packages perl-IO-Socket-INET6 perl-Socket6 .... mrtg works fine with IPV4-Addresses. When i specify a Target by IPV6-Address (or hostname resolving to a V6-address) mrtg fails. Here i have a small sample-config for V4 which is working: LogDir: /tmp ThreshDir: /tmp HtmlDir: /tmp ImageDir: /tmp LogDir: /tmp EnableIPv6: yes Target[bai-gw-i-oct]: ifInOctets.1&ifOutOctets.1:abc123 at 85.237.138.221 Title[bai-gw-i-oct]: Test MaxBytes[bai-gw-i-oct]: 100000000 ---------------------------------------------------- Here the same for V6 which fails. When running mrtg there is no snmp-packet sent to the network. LogDir: /tmp ThreshDir: /tmp HtmlDir: /tmp ImageDir: /tmp LogDir: /tmp EnableIPv6: yes Target[bai-gw-i-oct]: ifInOctets.1&ifOutOctets.1:abc123@[2001:b50:940f::f001] Title[bai-gw-i-oct]: Test MaxBytes[bai-gw-i-oct]: 100000000 # env LANG=C /usr/bin/mrtg /tmp/test.cfg SNMP Error: send_query: Address family not supported by protocol SNMPv1_Session (remote host: "2001:b50:940f::f001" [2001:b50:940f::f001].161) community: "abc123" request ID: 1156567655 PDU bufsize: 8000 bytes timeout: 2s retries: 5 backoff: 1) at /usr/bin/../lib64/mrtg2/SNMP_util.pm line 492 SNMPGET Problem for ifInOctets.1 ifOutOctets.1 sysUptime sysName on sni123@[2001:b50:940f::f001] at /usr/bin/mrtg line 2202 2011-09-03 14:13:01: ERROR: Target[bai-gw-i-oct][_IN_] ' $target->[0]{$mode} ' did not eval into defined data 2011-09-03 14:13:01: ERROR: Target[bai-gw-i-oct][_OUT_] ' $target->[0]{$mode} ' did not eval into defined data With snmpwalk (net-snmp-utils) i can reach the device via IPV4 and IPV6. Where is my mistake? Has anyone a hint? Thanks in advance, Florian