Re: [GLLUG] Using IPv6 addresses with Debian
On Friday, 12 March 2021 10:15:04 GMT John Winters via GLLUG wrote: > On 11/03/2021 15:14, Chris Bell via GLLUG wrote: > > Hello, > > IPv6 is designed so that a single address can be allocated to multiple > > interfaces, for example in a round-robin, and a single interface can have > > multiple addresses. > > I am using Debian 10 Buster on various computers including RaspberryPi and > > find that I can manually add addresses to a running computer, but if I > > attempt to configure multiple addresses only the last is accepted, and > > all but one is lost after a reboot. > > I've found various ways of configuring additional IPv6 addresses on > Raspbian / Debian Buster. It depends to a large extent on whether it's > headless or using a graphical desktop - where there are desktop client > components which want to get involved. > > On a plain (headless) Raspbian system, what I did was to edit > /etc/dhcpcd.conf and added the following two lines at the end: > > interface eth0 > static ip6_address=2001::4001/64 > > That causes dhcpcd to allocate that one in addition to the one it > calculates from the MAC address. > > On another headless Raspberry Pi, but running plain Debian Buster (not > Raspbian) I put the following in /etc/network/interfaces.d/eth0 > > auto eth0 > allow-hotplug eth0 > iface eth0 inet dhcp > > iface eth0 inet6 static > address 2001: > netmask 64 > > This causes the interface to be configured with *just* that IPv6 address > (no auto-calculated one) but you can always put additional ones there too. > > I suppose it depends on whether you're running dhcpcd or not. Raspbian > does by default, but Debian doesn't. > > HTH > John Thanks for the suggestion, which I will try, but I have had problems with even dhcpcd.conf on a raspberrypi. Systemd instructions go into great detail, but it still does not enable more than one IPv6 address per interface. I hope that debian 11 Bullseye will work. -- Chris Bell Website http://chrisbell.org.uk -- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
Re: [GLLUG] Using IPv6 addresses with Debian
On 11/03/2021 15:14, Chris Bell via GLLUG wrote: Hello, IPv6 is designed so that a single address can be allocated to multiple interfaces, for example in a round-robin, and a single interface can have multiple addresses. I am using Debian 10 Buster on various computers including RaspberryPi and find that I can manually add addresses to a running computer, but if I attempt to configure multiple addresses only the last is accepted, and all but one is lost after a reboot. I've found various ways of configuring additional IPv6 addresses on Raspbian / Debian Buster. It depends to a large extent on whether it's headless or using a graphical desktop - where there are desktop client components which want to get involved. On a plain (headless) Raspbian system, what I did was to edit /etc/dhcpcd.conf and added the following two lines at the end: interface eth0 static ip6_address=2001::4001/64 That causes dhcpcd to allocate that one in addition to the one it calculates from the MAC address. On another headless Raspberry Pi, but running plain Debian Buster (not Raspbian) I put the following in /etc/network/interfaces.d/eth0 auto eth0 allow-hotplug eth0 iface eth0 inet dhcp iface eth0 inet6 static address 2001: netmask 64 This causes the interface to be configured with *just* that IPv6 address (no auto-calculated one) but you can always put additional ones there too. I suppose it depends on whether you're running dhcpcd or not. Raspbian does by default, but Debian doesn't. HTH John -- Xronos Scheduler - https://xronos.uk/ All your school's schedule information in one place. Timetable, activities, homework, public events - the lot Live demo at https://schedulerdemo.xronos.uk/ -- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
Re: [GLLUG] Using IPv6 addresses with Debian
> > In fact I want to be able to use the addresses as source addresses under > specific conditions, such as local or global use. This has been working for > some time, and RADVD is configured to specify which to use. Given a choice > of prefix the one chosen should automatically be the one which has the > nearest to the destination prefix. There are valid reasons for a single interface to have more than one current source prefix, including multi-homed sites with connections provided by more than one ISP for reliability (perhaps one preferred if available for cost reasons) and when using site-local addresses. RFC3513 Internet Protocol Version 6 (IPv6) Addressing Architecture defines fe80::/64 as link local, still current defines fec0::/10 as site local, now deprecated by RFC 4291 IP Version 6 Addressing Architecture but RFC4193 Unique Local IPv6 Unicast Addresses defines fc00::/7 as site local, although fd00::/8 is the only one currently in use, (October 2005, and has no current amendments) RFC6724 Default Address Selection for Internet Protocol Version 6 (IPv6) specifies how the correct address should be selected The Shorewall(6) firewall system is designed to cope with these possibilities and can be used to enforce the way different addresses may be used. I have been receiving SMTP to my RaspberryPi email gateway using exim and spamassassin, and the gateway could only access my RaspberryPi hubbed host mail server, again running exim and spamassassin, using my site local network addresses, and the gateway managed to block huge numbers of direct attacks. -- Chris Bell Website http://chrisbell.org.uk -- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
Re: [GLLUG] Using IPv6 addresses with Debian
On Thursday, 11 March 2021 15:22:35 GMT Martin A. Brooks via GLLUG wrote: > On 2021-03-11 15:14, Chris Bell via GLLUG wrote: > > IPv6 is designed so that a single address can be allocated to multiple > > interfaces, for example in a round-robin > > That's not a "design" of IPv6 but rather a function of 802.3ad. Thankfully the IETF have spent a lot of time and effort designing and specifying that, with multiple RFC's. -- Chris Bell Website http://chrisbell.org.uk -- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
Re: [GLLUG] Using IPv6 addresses with Debian
On Thursday, 11 March 2021 15:22:11 GMT Andy Smith via GLLUG wrote: > Hi Chris, > > On Thu, Mar 11, 2021 at 03:14:42PM +, Chris Bell via GLLUG wrote: > > I am using Debian 10 Buster on various computers including RaspberryPi and > > find that I can manually add addresses to a running computer, but if I > > attempt to configure multiple addresses only the last is accepted, and > > all but one is lost after a reboot. > > I don't see a concrete question in your email, but for what it's > worth I add multiple IPv6 addresses on Debian by using pre-up hooks > in the /etc/network/interfaces file, e.g.: > > iface eth0 inet6 static > address 2001:ba8:1f1:f019::2 > netmask 64 > gateway fe80::fcff::feff: > pre-up ip -6 addr add 2001:ba8:1f1:f019::3/64 dev $IFACE preferred_lft 0 > pre-up ip -6 addr add 2001:ba8:1f1:f019::4/64 dev $IFACE preferred_lft 0 > > The "preferred_lft 0" bit is so that the addresses are present and > usable for daemons to bind to, but will never be used as a source > address for outgoing traffic. Without that, the last added address > will be used as the source address. > > Cheers, > Andy In fact I want to be able to use the addresses as source addresses under specific conditions, such as local or global use. This has been working for some time, and RADVD is configured to specify which to use. Given a choice of prefix the one chosen should automatically be the one which has the nearest to the destination prefix. -- Chris Bell Website http://chrisbell.org.uk -- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
Re: [GLLUG] Using IPv6 addresses with Debian
On Thursday, 11 March 2021 15:22:11 GMT Andy Smith via GLLUG wrote: > Hi Chris, > > On Thu, Mar 11, 2021 at 03:14:42PM +, Chris Bell via GLLUG wrote: > > I am using Debian 10 Buster on various computers including RaspberryPi and > > find that I can manually add addresses to a running computer, but if I > > attempt to configure multiple addresses only the last is accepted, and > > all but one is lost after a reboot. > > I don't see a concrete question in your email, but for what it's > worth I add multiple IPv6 addresses on Debian by using pre-up hooks > in the /etc/network/interfaces file, e.g.: > > iface eth0 inet6 static > address 2001:ba8:1f1:f019::2 > netmask 64 > gateway fe80::fcff::feff: > pre-up ip -6 addr add 2001:ba8:1f1:f019::3/64 dev $IFACE preferred_lft 0 > pre-up ip -6 addr add 2001:ba8:1f1:f019::4/64 dev $IFACE preferred_lft 0 > > The "preferred_lft 0" bit is so that the addresses are present and > usable for daemons to bind to, but will never be used as a source > address for outgoing traffic. Without that, the last added address > will be used as the source address. > > Cheers, > Andy Thanks for the reply, I will try that. -- Chris Bell Website http://chrisbell.org.uk -- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
Re: [GLLUG] Using IPv6 addresses with Debian
On 2021-03-11 15:14, Chris Bell via GLLUG wrote: IPv6 is designed so that a single address can be allocated to multiple interfaces, for example in a round-robin That's not a "design" of IPv6 but rather a function of 802.3ad. -- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
Re: [GLLUG] Using IPv6 addresses with Debian
Hi Chris, On Thu, Mar 11, 2021 at 03:14:42PM +, Chris Bell via GLLUG wrote: > I am using Debian 10 Buster on various computers including RaspberryPi and > find > that I can manually add addresses to a running computer, but if I attempt to > configure multiple addresses only the last is accepted, and all but one is > lost > after a reboot. I don't see a concrete question in your email, but for what it's worth I add multiple IPv6 addresses on Debian by using pre-up hooks in the /etc/network/interfaces file, e.g.: iface eth0 inet6 static address 2001:ba8:1f1:f019::2 netmask 64 gateway fe80::fcff::feff: pre-up ip -6 addr add 2001:ba8:1f1:f019::3/64 dev $IFACE preferred_lft 0 pre-up ip -6 addr add 2001:ba8:1f1:f019::4/64 dev $IFACE preferred_lft 0 The "preferred_lft 0" bit is so that the addresses are present and usable for daemons to bind to, but will never be used as a source address for outgoing traffic. Without that, the last added address will be used as the source address. Cheers, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting -- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
