1 Dec
2008
1 Dec
'08
2:02 a.m.
Hi,
BitFolk's IP assignment has grown from 212.13.194.0/24 (i.e.
212.13.194.0 -> 212.13.194.255) to 212.13.194.0/23 (i.e.
212.13.194.0 -> 212.13.195.255). This means that almost all
customers in the UK need to change their netmask.
This is largely harmless since all it means is that you cannot
communicate with IPs in 212.13.195.x, and for some time to come that
will only be other customers. However, eventually I will need to
start putting infrastructure into there too.
Here are some instructions on how to change the settings. You
should be able to do this without losing any network connectivity.
These instructions are for Debian/Ubuntu, so Centos and Gentoo folks
you are on your own unfortunately, but this isn't complicated -- I
believe the only Debian-specific bit is step 4.
1. Make sure you have access to your Xen shell console in case
anything goes wrong.
2. MAKE SURE YOU HAVE ACCESS TO YOUR XEN CONSOLE IN CASE ANYTHING
GOES WRONG. REALLY. LOG IN AND CHECK.
3. Check that you actually need to do this. An example of a VPS
that needs to make a change:
$ /sbin/ip ro
212.13.194.0/24 dev eth0 proto kernel scope link src 212.13.194.75
default via 212.13.194.1 dev eth0
Note the /24 -- it should be /23.
4. Fix your config file, /etc/network/interfaces. Here's an example
of the content before it is fixed:
----[ /etc/network/interfaces ]--------------------------------------
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 212.13.194.75
netmask 255.255.255.0
gateway 212.13.194.1
----[ /etc/network/interfaces ]--------------------------------------
Here's an example after fixing:
----[ /etc/network/interfaces ]--------------------------------------
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 212.13.194.75
netmask 255.255.254.0
gateway 212.13.194.1
----[ /etc/network/interfaces ]--------------------------------------
The only line changed is the netmask.
You should change this config file ready for the next boot, but
it won't alter your current settings.
5. Find your current IP address:
$ /sbin/ip -4 addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
inet 127.0.0.1/8 scope host lo
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
inet 212.13.194.75/24 scope global eth0
In this example my IP address is 212.13.194.75.
6. Add it with the correct settings:
$ /sbin/ip addr add 212.13.194.75/23 dev eth0
That should complete without error.
7. Remove the old one:
$ /sbin/ip addr del 212.13.194.75/24 dev eth0
That should complete without error.
8. Check that your routing table is now correct:
$ /sbin/ip ro
212.13.194.0/23 dev eth0 proto kernel scope link src 212.13.194.75
default via 212.13.194.1 dev eth0
That's it. You should not lose connectivity at any point during this
procedure.
If you're already using the /23 setup (anyone set up probably in the
last 2 weeks, but do check) then you don't need to do anything.
If you have your own net block routed to you then you don't need to
do anything.
If you have multiple IPs then your interfaces file might look a bit
like this:
----[ /etc/network/interfaces ]--------------------------------------
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 212.13.194.75
netmask 255.255.255.0
gateway 212.13.194.1
auto eth0:1
iface eth0:1 inet static
address 212.13.194.116
netmask 255.255.255.255
----[ /etc/network/interfaces ]--------------------------------------
The netmask of aliased IPs (eth0:1, eth0:2, ...) does not need to
change. IP aliases on the same network as another interface are
supposed to be 255.255.255.255 netmask. So in this case you would
only need to be fixing the netmask for the eth0 entry, and
adding/deleting 212.13.194.75.
If you have any questions please feel free to mail me on or offlist
about it before you do anything.
If Centos/Gentoo folks could contribute a HOWTO for this then that
would be great.
Cheers,
Andy
--
http://bitfolk.com/ -- No-nonsense VPS hosting
Encrypted mail welcome - keyid 0x604DE5DB
1 Dec
1 Dec
4:31 a.m.
Andy Smith wrote:
This is largely harmless since all it means is that
you cannot
communicate with IPs in 212.13.195.x, and for some time to come that
will only be other customers. However, eventually I will need to
start putting infrastructure into there too.
Wouldn't it be better to just use /24 subnets instead of getting people
to update all the time, then if/when machines between subnets need to
communicate with each other the router just reflects the connection back
on the LAN and the "MAC routing" updates and everything just works hunky
dory... ?
--
Best regards,
Duane
http://www.freeauth.org - Enterprise Two Factor Authentication
http://www.nodedb.com - Think globally, network locally
http://www.sydneywireless.com - Telecommunications Freedom
http://e164.org - Global Communication for the 21st Century
"In the long run the pessimist may be proved right,
but the optimist has a better time on the trip."
2 Dec
2 Dec
11:14 a.m.
New subject: IMPORTANT: Re: Network settings change needed for most UK customers
On Mon, Dec 01, 2008 at 02:31:45PM +1000, Duane at e164 dot org wrote:
Wouldn't it be better to just use /24 subnets
instead of getting people
to update all the time, then if/when machines between subnets need to
communicate with each other the router just reflects the connection back
on the LAN and the "MAC routing" updates and everything just works hunky
dory... ?
Yeah I've been a bit hasty anyway in just repeating what was done
before. With the routed config now, it all goes through dom0 anyway
so nobody actually needs to change anything, sorry!
For the benefit of anyone reading who did not get that:
Ignore this thread, you don't need to do anything. Confirm
you can ping 212.13.195.4 for example.
That said, if you already did change it, that's harmless too.
Apologies,
Andy
--
http://bitfolk.com/ -- No-nonsense VPS hosting
Encrypted mail welcome - keyid 0x604DE5DB
12:05 p.m.
New subject: IMPORTANT: Re: Network settings change needed for most UK customers
Andy Smith wrote:
Yeah I've been a bit hasty anyway in just
repeating what was done
before. With the routed config now, it all goes through dom0 anyway
so nobody actually needs to change anything, sorry!
Yup, can ping 212.13.195.4 just fine without change anything ;)
--
Best regards,
Duane
http://www.freeauth.org - Enterprise Two Factor Authentication
http://www.nodedb.com - Think globally, network locally
http://www.sydneywireless.com - Telecommunications Freedom
http://e164.org - Global Communication for the 21st Century
"In the long run the pessimist may be proved right,
but the optimist has a better time on the trip."
1 Dec
1 Dec
8:12 a.m.
On CentOS:
nano /etc/sysconfig/network-scripts/ifcfg-eth0
Update NETMASK line from 255.255.255.0 to 255.255.254.0, and save
service network restart
Done :o)
Paul
Andy Smith wrote:
Hi,
BitFolk's IP assignment has grown from 212.13.194.0/24 (i.e.
212.13.194.0 -> 212.13.194.255) to 212.13.194.0/23 (i.e.
212.13.194.0 -> 212.13.195.255). This means that almost all
customers in the UK need to change their netmask.
This is largely harmless since all it means is that you cannot
communicate with IPs in 212.13.195.x, and for some time to come that
will only be other customers. However, eventually I will need to
start putting infrastructure into there too.
Here are some instructions on how to change the settings. You
should be able to do this without losing any network connectivity.
These instructions are for Debian/Ubuntu, so Centos and Gentoo folks
you are on your own unfortunately, but this isn't complicated -- I
believe the only Debian-specific bit is step 4.
1. Make sure you have access to your Xen shell console in case
anything goes wrong.
2. MAKE SURE YOU HAVE ACCESS TO YOUR XEN CONSOLE IN CASE ANYTHING
GOES WRONG. REALLY. LOG IN AND CHECK.
3. Check that you actually need to do this. An example of a VPS
that needs to make a change:
$ /sbin/ip ro
212.13.194.0/24 dev eth0 proto kernel scope link src 212.13.194.75
default via 212.13.194.1 dev eth0
Note the /24 -- it should be /23.
4. Fix your config file, /etc/network/interfaces. Here's an example
of the content before it is fixed:
----[ /etc/network/interfaces ]--------------------------------------
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 212.13.194.75
netmask 255.255.255.0
gateway 212.13.194.1
----[ /etc/network/interfaces ]--------------------------------------
Here's an example after fixing:
----[ /etc/network/interfaces ]--------------------------------------
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 212.13.194.75
netmask 255.255.254.0
gateway 212.13.194.1
----[ /etc/network/interfaces ]--------------------------------------
The only line changed is the netmask.
You should change this config file ready for the next boot, but
it won't alter your current settings.
5. Find your current IP address:
$ /sbin/ip -4 addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
inet 127.0.0.1/8 scope host lo
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
inet 212.13.194.75/24 scope global eth0
In this example my IP address is 212.13.194.75.
6. Add it with the correct settings:
$ /sbin/ip addr add 212.13.194.75/23 dev eth0
That should complete without error.
7. Remove the old one:
$ /sbin/ip addr del 212.13.194.75/24 dev eth0
That should complete without error.
8. Check that your routing table is now correct:
$ /sbin/ip ro
212.13.194.0/23 dev eth0 proto kernel scope link src 212.13.194.75
default via 212.13.194.1 dev eth0
That's it. You should not lose connectivity at any point during this
procedure.
If you're already using the /23 setup (anyone set up probably in the
last 2 weeks, but do check) then you don't need to do anything.
If you have your own net block routed to you then you don't need to
do anything.
If you have multiple IPs then your interfaces file might look a bit
like this:
----[ /etc/network/interfaces ]--------------------------------------
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 212.13.194.75
netmask 255.255.255.0
gateway 212.13.194.1
auto eth0:1
iface eth0:1 inet static
address 212.13.194.116
netmask 255.255.255.255
----[ /etc/network/interfaces ]--------------------------------------
The netmask of aliased IPs (eth0:1, eth0:2, ...) does not need to
change. IP aliases on the same network as another interface are
supposed to be 255.255.255.255 netmask. So in this case you would
only need to be fixing the netmask for the eth0 entry, and
adding/deleting 212.13.194.75.
If you have any questions please feel free to mail me on or offlist
about it before you do anything.
If Centos/Gentoo folks could contribute a HOWTO for this then that
would be great.
Cheers,
Andy
------------------------------------------------------------------------
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users mailing list
users(a)lists.bitfolk.com
https://lists.bitfolk.com/mailman/listinfo/users
8:56 a.m.
2008/12/1 Paul Lewis <bitfolk(a)pjlewis.org>rg>:
On CentOS:
nano /etc/sysconfig/network-scripts/ifcfg-eth0
Update NETMASK line from 255.255.255.0 to 255.255.254.0, and save
service network restart
Done :o)
Damn, beat me to it. Though I'd have used vim :p
I also only found out about "service network restart" recently. Before
that I'd just have used:
ifdown eth0 && ifup eth0
ho-hum, same result.
1:32 p.m.
Philip Veale wrote:
2008/12/1 Paul Lewis <bitfolk(a)pjlewis.org>rg>:
almost.
Service network restart takes down all your network interfaces and then
brings them back in order... including localhost.
sometimes the ifup/down route is the most sane :)
Stuart
--
Stuart Sears RHC*
"It's today!" said Piglet.
"My favourite day," said Pooh.
On CentOS:
nano /etc/sysconfig/network-scripts/ifcfg-eth0
Update NETMASK line from 255.255.255.0 to 255.255.254.0, and save
service network restart
Done :o)
Damn, beat me to it. Though I'd have used vim :p
I also only found out about "service network restart" recently. Before
that I'd just have used:
ifdown eth0 && ifup eth0
ho-hum, same result.
5622
days inactive
5623
days old
6 comments
5 participants
participants (5)
-
Andy Smith -
Duane at e164 dot org -
Paul Lewis -
Philip Veale -
Stuart Sears