Showing entries with tag "IPV6".

Found 3 entries

PHP: IPV6 reverse DNS entries

Reverse DNS (PTR) entries in IPV6 are different than their IPV4 counterparts. To create an IPV6 reverse entry, you have to: fully expand the address, reverse it, and add a period between each character.

For example: 2001:db8::60 reverses to 0.6.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.

I wrote a simple PHP function to handle this for me:

function ipv6_ptr($ip_str) {
    $hex = unpack("H*hex", inet_pton($ip_str));
    $str = strrev($hex['hex']);
    $p   = str_split($str);
    $ret = join(".",$p);

    return $ret;
}
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CentOS: Multiple static IPV6 addresses

I needed to apply multiple static IPV6 addresses to a single interface under Fedora/CentOS. To do this you'll need to add an IPV6ADDR_SECONDARIES line to your /etc/sysconfig/network-scripts/ifcfg-eth0 so that it looks like this:

IPV6_DEFAULTGW=2001:db8::1
IPV6_AUTOCONF=no
IPV6ADDR=2001:db8::50/64
IPV6ADDR_SECONDARIES="2001:db8::40/64 2001:db8::30/64"

Note: Addresses are added in reverse order. Outbound traffic will use the last secondary IP added.

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Cisco: Change IPV6 SLAAC lifetimes

The default IPV6 valid lifetime for a SLAAC configured address is 30 days, and preferred lifetime is 7 days. You can change these lifetimes with this command:

conf t
int vlan 568
ipv6 nd prefix default 86400 14400

This can be used to effectively "time-out" an auto-configured address.

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