From ip-sysctl.txt file in kernel documentation I can see following description for max_addresses: max_addresses - INTEGER Number of maximum addresses per interface. 0 disables limitation. It is recommended not set too large value (or 0) because it would be too easy way to crash kernel to allow to create too much of autoconfigured addresses. Default: 16 On my machine all parameters are set to default value 16: # sysctl -a|grep max_addresses net.ipv6.conf.all.max_addresses = 16 net.ipv6.conf.default.max_addresses = 16 net.ipv6.conf.lo.max_addresses = 16 net.ipv6.conf.eth0.max_addresses = 16 To my understanding I should not be able to create more than 16 IP addresses, but in fact I am able do it: # for i in `seq 1 16`; do ip addr add fec0::$i/64 dev eth0; done # ip addr add fec0::17/64 dev eth0 # ip -6 addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000 inet6 fec0::17/64 scope site valid_lft forever preferred_lft forever inet6 fec0::16/64 scope site valid_lft forever preferred_lft forever inet6 fec0::15/64 scope site valid_lft forever preferred_lft forever inet6 fec0::14/64 scope site valid_lft forever preferred_lft forever inet6 fec0::13/64 scope site valid_lft forever preferred_lft forever inet6 fec0::12/64 scope site valid_lft forever preferred_lft forever inet6 fec0::11/64 scope site valid_lft forever preferred_lft forever inet6 fec0::10/64 scope site valid_lft forever preferred_lft forever inet6 fec0::9/64 scope site valid_lft forever preferred_lft forever inet6 fec0::8/64 scope site valid_lft forever preferred_lft forever inet6 fec0::7/64 scope site valid_lft forever preferred_lft forever inet6 fec0::6/64 scope site valid_lft forever preferred_lft forever inet6 fec0::5/64 scope site valid_lft forever preferred_lft forever inet6 fec0::4/64 scope site valid_lft forever preferred_lft forever inet6 fec0::3/64 scope site valid_lft forever preferred_lft forever inet6 fec0::2/64 scope site valid_lft forever preferred_lft forever inet6 fec0::1/64 scope site valid_lft forever preferred_lft forever inet6 fe80::223:aeff:fe77:44ba/64 scope link valid_lft forever preferred_lft forever
If this parameter applies only for auto-configured IP addressed, please state it more clearly in docs or rename the parameter to show that it refers to auto-configuration.
(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Wed, 17 Feb 2010 14:12:28 GMT bugzilla-daemon@bugzilla.kernel.org wrote: > http://bugzilla.kernel.org/show_bug.cgi?id=15342 > > Summary: max_address parameter is not taken into consideration > when IPv6 addresses are created > Product: Networking > Version: 2.5 > Kernel Version: 2.6.32.5 > Platform: All > OS/Version: Linux > Tree: Mainline > Status: NEW > Severity: low > Priority: P1 > Component: IPV6 > AssignedTo: yoshfuji@linux-ipv6.org > ReportedBy: nedyalkor@gmail.com > Regression: No > > > >From ip-sysctl.txt file in kernel documentation I can see following > description > for max_addresses: > max_addresses - INTEGER > Number of maximum addresses per interface. 0 disables limitation. > It is recommended not set too large value (or 0) because it would > be too easy way to crash kernel to allow to create too much of > autoconfigured addresses. > Default: 16 > > On my machine all parameters are set to default value 16: > # sysctl -a|grep max_addresses > net.ipv6.conf.all.max_addresses = 16 > net.ipv6.conf.default.max_addresses = 16 > net.ipv6.conf.lo.max_addresses = 16 > net.ipv6.conf.eth0.max_addresses = 16 > > To my understanding I should not be able to create more than 16 IP addresses, > but in fact I am able do it: > > # for i in `seq 1 16`; do ip addr add fec0::$i/64 dev eth0; done > # ip addr add fec0::17/64 dev eth0 > # ip -6 addr > 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 > inet6 ::1/128 scope host > valid_lft forever preferred_lft forever > 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000 > inet6 fec0::17/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::16/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::15/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::14/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::13/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::12/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::11/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::10/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::9/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::8/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::7/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::6/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::5/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::4/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::3/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::2/64 scope site > valid_lft forever preferred_lft forever > inet6 fec0::1/64 scope site > valid_lft forever preferred_lft forever > inet6 fe80::223:aeff:fe77:44ba/64 scope link > valid_lft forever preferred_lft forever > > > If this parameter applies only for auto-configured IP addressed, please state > it more clearly in docs or rename the parameter to show that it refers to > auto-configuration. >