Hello all,
Using bullseye lite (terminal only) and DHCP (dhclient) I'm trying to configure two network interfaces, connected to different networks with their own routers.
I would like to configure one or both of the eth? interfaces as a LAN only connection, meaning without a "default gateway" and/or DNS server adresses and such.
I've found some information about what to edit in /etc/dhcp/dhclient.conf, but after rebooting and checking the output of "route" I still see a "gateway" entry for eth1.
Does anybody know what to add/remove/change in that dhclient.conf file to
get it to work ?
Remark: I've also seen suggestions to just give eth1 a high metric (so the eth0 gateway is considered first), but that doesn't work for me as eth0
might not be always available.
Regards,
Rudy Wieser
Do you use NetworkManager? Or dhclient directly? Systemd?
This gives suggestions for both NM and dhclient: https://unix.stackexchange.com/questions/399659/how-to-avoid-dhclient-default-gateway-on-an-interface
However systemd doesn't use dhclient.conf (I am told). See here: https://serverfault.com/questions/674731/multiple-dhcp-uplinks-how-to-ignore-dns-and-default-route-on-all-but-one
Last answer mentions systemd.
Chris,
Do you use NetworkManager? Or dhclient directly? Systemd?
I tried "nmcli" but got the response that NetworkManager wasn't running.
I do have a /etc/dhcp/dhclient.conf file, but I'm not sure at all if its actually used (editing it doesn't seem to change anything).
As for systemd ? It looks like it, as I have a "/etc/systemd" folder.
So, I've got two outof three, with one maybe.
This gives suggestions for both NM and dhclient:
https://unix.stackexchange.com/questions/399659/how-to-avoid-dhclient-default-gateway-on-an-interface
Thats one of the links I found from which I applied the "Another way: dhclient.conf" suggstion. Alas, I still got a "default gateway" on eth1.
However systemd doesn't use dhclient.conf (I am told). See here:
https://serverfault.com/questions/674731/multiple-dhcp-uplinks-how-to-ignore-dns-and-default-route-on-all-but-one
Yep, found that one too. The second post (by Nils Toedtmann) says the same as your link. :-)
Last answer mentions systemd.
I read that too, but although I can find the "/etc/systemd/network" folder itself I simply do not have enough information to be sure what the "*.interface" name should be. Next to that I do not see, under "[DHCP]",
any mentioning of a gateway, but to see the "lets use a high metric" hack that I, as mentioned, can't use. :-\
In short, the presence of a "dhclient.conf" *and* "/etc/systemd" makes me quite unsure which one actually gouverns the network configuration. Hence
my post.
Regards,
Rudy Wieser
Are you sure you're using dhclient?
What does `ps ax | grep dhc` say?
Just looked at my 11.6 install. It uses dhcpcd
If yours does too, try putting
interface eth1
nogateway
at the end of /etc/dhcpcd.conf
Chris,
Are you sure you're using dhclient?
Reasonably sure : I used
/var/log/syslog | grep -Ei 'dhcp'.
(https://superuser.com/questions/944687/how-to-see-what-dhcp-client-does)
to check, and had a number of lines mentioning "dhcpcd" with one of them mentioning "adding default route", showing the IP of the router servicing
the eth1 LAN
What does `ps ax | grep dhc` say?
It says
/user/sbin/dhcpcd -w -q
Just looked at my 11.6 install. It uses dhcpcd
Could you tell me how you checked that ?
If yours does too, try putting
interface eth1
nogateway
at the end of /etc/dhcpcd.conf
That does seem to have done the trick. Thanks.
It also means I have to do a bit more googeling, but now focussed on that paricular file.
A question though : if that file is there to configure the interfaces, what than is the "/etc/dhcp/dhclient.conf" file about ? Do you know ?
And strangely enough, I've only seen that "dhcpcd.conf" file being mentioned once,
https://raspberrypi.stackexchange.com/questions/127497/how-to-setup-eth1-with-fixed-ip
but must admit I skipped it as it was talking about setting a fixed IP.
Regards,
Rudy Wieser
A question though : if that file is there to configure the interfaces,
what than is the "/etc/dhcp/dhclient.conf" file about ? Do you know ?
it is to configure dhclient
dhclient and dhcpcd are 2 *different* methods
And strangely enough, I've only seen that "dhcpcd.conf" file being
mentioned
once,
https://raspberrypi.stackexchange.com/questions/127497/how-to-setup-eth1-with-fixed-ip
that's coz raspbian uses dhcpcd
look at /usr/lib/systemd/system/dhcpcd.service
systemctl status dhcpcd.service
Chris,
A question though : if that file is there to configure the interfaces,
what than is the "/etc/dhcp/dhclient.conf" file about ? Do you know ?
it is to configure dhclient
:-) That much I already assumed.
dhclient and dhcpcd are 2 *different* methods
Well, that explains everything. I've been focussing on and modifying an unused configuration file. No wonder nothing seemed to work. :-(
I must say that I don't quite understand why bullseye *lite* would carry two seperate network configuration methods - one of which it doesn't even use - while not bothering to including supporting files for when someone (like me) wants to do a bit of GPIO or graphics using GCC.
And strangely enough, I've only seen that "dhcpcd.conf" file being
mentioned
once,
https://raspberrypi.stackexchange.com/questions/127497/how-to-setup-eth1-with-fixed-ip
that's coz raspbian uses dhcpcd
I've seen post about dhcpcd dated as far back as 2011. I would have expected that my two/three day stint googeling would have popped up that name a few more times - Especially in relation to the RPi by people having a similar "how to configure the network" problem.
Than again, how many people would want to create a "LAN only" interface ...
look at /usr/lib/systemd/system/dhcpcd.service
Thanks. I just did. Can't say I understand what whats in it means though. More to google I guess. :-)
systemctl status dhcpcd.service
Apart from recognising the the syslog entries at the bottom the same goes here.
Thanks for the help and info.
Regards,
Rudy Wieser
I've always thought the lite moniker just meant no X
If I'd looked at my installation earlier I'd probably have twigged you
were using dhcpcd not dhclient.
In short : do you know of any source of info (website) which explains the network configuration, focussed on what is currently used by bullseye ?
Besides that, I would also would like to have some more information about (possibly) disabeling/changing DNS and other stuff dhpdcd seems to ask the dhcp server for* (even when DNS servers can't be reached without a default gateway).DHCP is a noddy default setup for a client machine that is connected to
A new question though (if you don't mind) : I've been trying to disable ipv6 too, and reading the man page for dhcpcd.conf I saw that I could use "ipv4only".
A new question though (if you don't mind) : I've been trying to disable
ipv6 too, and reading the man page for dhcpcd.conf I saw that I could use "ipv4only".
I've put that just above the "interface eth1" line (assuming that it
would than work for all interfaces), but "ifconfig" still shows ipv6
adresses for both "eth1" as well as "lo" (eth0 is disconnected).
On 26/04/2023 08:20, R.Wieser wrote:
Don't get too hung up on the raspbian/bullseye focus.
In short : do you know of any source of info (website) which explains the
network configuration, focussed on what is currently used by bullseye ?
dhcpcd configuration is dhcpcd configuration no matter which distro
you're using.
Even the systemd invocation used by debian and thus raspbian is just a straight invocation of dhcpcd.
As previous, try the archwiki.
On 26/04/2023 13:07, Chris Elvidge wrote:
On 26/04/2023 08:20, R.Wieser wrote:I thought the OP was trying to set up a DHCP client, not a server?
Don't get too hung up on the raspbian/bullseye focus.
In short : do you know of any source of info (website) which explains
the
network configuration, focussed on what is currently used by bullseye ?
dhcpcd configuration is dhcpcd configuration no matter which distro
you're using.
Even the systemd invocation used by debian and thus raspbian is just a
straight invocation of dhcpcd.
As previous, try the archwiki.
On 26/04/2023 13:20, The Natural Philosopher wrote:
On 26/04/2023 13:07, Chris Elvidge wrote:
On 26/04/2023 08:20, R.Wieser wrote:I thought the OP was trying to set up a DHCP client, not a server?
Don't get too hung up on the raspbian/bullseye focus.
In short : do you know of any source of info (website) which
explains the
network configuration, focussed on what is currently used by bullseye ? >>>>
dhcpcd configuration is dhcpcd configuration no matter which distro
you're using.
Even the systemd invocation used by debian and thus raspbian is just
a straight invocation of dhcpcd.
As previous, try the archwiki.
dhcpcd is client, isn't it?
On 26/04/2023 14:21, Chris Elvidge wrote:
On 26/04/2023 13:20, The Natural Philosopher wrote:Thought it was the server
On 26/04/2023 13:07, Chris Elvidge wrote:
On 26/04/2023 08:20, R.Wieser wrote:I thought the OP was trying to set up a DHCP client, not a server?
Don't get too hung up on the raspbian/bullseye focus.
In short : do you know of any source of info (website) which
explains the
network configuration, focussed on what is currently used by
bullseye ?
dhcpcd configuration is dhcpcd configuration no matter which distro
you're using.
Even the systemd invocation used by debian and thus raspbian is just
a straight invocation of dhcpcd.
As previous, try the archwiki.
dhcpcd is client, isn't it?
dhclient is the client. But I think there are many clients now. What
with systemd and network manager its all a muddle.
On Wed, 26 Apr 2023 09:20:30 +0200
"R.Wieser" <address@is.invalid> wrote:
A new question though (if you don't mind) : I've been trying to disable
ipv6 too, and reading the man page for dhcpcd.conf I saw that I could use
"ipv4only".
I've put that just above the "interface eth1" line (assuming that it
would than work for all interfaces), but "ifconfig" still shows ipv6
adresses for both "eth1" as well as "lo" (eth0 is disconnected).
What sort of ipv6 addresses ? If it is only link local ipv6
addresses (starting fe80::) then they don't come from DHCPCD but from IPv6 neighbour discovery and are probably quite hard to get rid of but they're only valid on a LAN segment so I wouldn't worry about them too much.
On 26/04/2023 14:45, Chris Elvidge wrote:
No. See previous. dhcpcd and dhclient are *different* dhcp clients.Ubuntu is still using dhclient, isn't it?
dhclient is supplied by the ISC. dhclient is not normally used by
debian, slackware (or any other distros I use). They all use dhcpcd.
Even the systemd implementation used in debian uses dhcpcd. See
/usr/lib/systemd/system/dhcpcd.service
https://www.isc.org/blogs/dhcp-client-relay-eom/ says "ISC plans to
end maintenance of the ISC DHCP client and relay by the end of Q1,
2022." Hence dhclient is end-of-life (IMHO).
I don't know about NetworkManager (or nmcli), I don't use it. A quick
look on Archwiki and /usr/lib/systemd/system/NetworkManager.service
says it is dbus based.
No. See previous. dhcpcd and dhclient are *different* dhcp clients.
dhclient is supplied by the ISC. dhclient is not normally used by
debian, slackware (or any other distros I use). They all use dhcpcd.
Even the systemd implementation used in debian uses dhcpcd. See /usr/lib/systemd/system/dhcpcd.service https://www.isc.org/blogs/dhcp-client-relay-eom/ says "ISC plans to end maintenance of the ISC DHCP client and relay by the end of Q1, 2022."
Hence dhclient is end-of-life (IMHO).
I don't know about NetworkManager (or nmcli), I don't use it. A quick
look on Archwiki and /usr/lib/systemd/system/NetworkManager.service says
it is dbus based.
On 26/04/2023 17:22, Pancho wrote:
On 26/04/2023 14:45, Chris Elvidge wrote:
No. See previous. dhcpcd and dhclient are *different* dhcp clients.Ubuntu is still using dhclient, isn't it?
dhclient is supplied by the ISC. dhclient is not normally used by
debian, slackware (or any other distros I use). They all use dhcpcd.
Even the systemd implementation used in debian uses dhcpcd. See
/usr/lib/systemd/system/dhcpcd.service
https://www.isc.org/blogs/dhcp-client-relay-eom/ says "ISC plans to
end maintenance of the ISC DHCP client and relay by the end of Q1,
2022." Hence dhclient is end-of-life (IMHO).
I don't know about NetworkManager (or nmcli), I don't use it. A quick
look on Archwiki and /usr/lib/systemd/system/NetworkManager.service
says it is dbus based.
No idea.
Does `ps ax | grep dhc` give a clue?
Does nmcli work? -> uses NetworkManager
On 26/04/2023 17:22, Pancho wrote:
On 26/04/2023 14:45, Chris Elvidge wrote:
No. See previous. dhcpcd and dhclient are *different* dhcp clients.Ubuntu is still using dhclient, isn't it?
dhclient is supplied by the ISC. dhclient is not normally used by
debian, slackware (or any other distros I use). They all use dhcpcd.
Even the systemd implementation used in debian uses dhcpcd. See
/usr/lib/systemd/system/dhcpcd.service
https://www.isc.org/blogs/dhcp-client-relay-eom/ says "ISC plans to
end maintenance of the ISC DHCP client and relay by the end of Q1,
2022." Hence dhclient is end-of-life (IMHO).
I don't know about NetworkManager (or nmcli), I don't use it. A quick
look on Archwiki and /usr/lib/systemd/system/NetworkManager.service
says it is dbus based.
No idea.
Does `ps ax | grep dhc` give a clue?
Does nmcli work? -> uses NetworkManager
On 26/04/2023 17:22, Pancho wrote:
On 26/04/2023 14:45, Chris Elvidge wrote:
No. See previous. dhcpcd and dhclient are *different* dhcp clients.Ubuntu is still using dhclient, isn't it?
dhclient is supplied by the ISC. dhclient is not normally used by
debian, slackware (or any other distros I use). They all use dhcpcd.
Even the systemd implementation used in debian uses dhcpcd. See
/usr/lib/systemd/system/dhcpcd.service
https://www.isc.org/blogs/dhcp-client-relay-eom/ says "ISC plans to
end maintenance of the ISC DHCP client and relay by the end of Q1,
2022." Hence dhclient is end-of-life (IMHO).
I don't know about NetworkManager (or nmcli), I don't use it. A quick
look on Archwiki and /usr/lib/systemd/system/NetworkManager.service
says it is dbus based.
No idea.
Does `ps ax | grep dhc` give a clue?
Does nmcli work? -> uses NetworkManager
On 26/04/2023 13:36, Ahem A Rivet's Shot wrote:
On Wed, 26 Apr 2023 09:20:30 +0200
"R.Wieser" <address@is.invalid> wrote:
A new question though (if you don't mind) : I've been trying to disable
ipv6 too, and reading the man page for dhcpcd.conf I saw that I could use >>> "ipv4only".
I've put that just above the "interface eth1" line (assuming that it
would than work for all interfaces), but "ifconfig" still shows ipv6
adresses for both "eth1" as well as "lo" (eth0 is disconnected).
What sort of ipv6 addresses ? If it is only link local ipv6
addresses (starting fe80::) then they don't come from DHCPCD but from IPv6 >> neighbour discovery and are probably quite hard to get rid of but they're
only valid on a LAN segment so I wouldn't worry about them too much.
It seems there are 2 ways to totally disable ipv6 https://www.howtoraspberry.com/2020/04/disable-ipv6-on-raspberry-pi/
1) Pi only: add 'ipv6.disable=1' to end of line in /boot/cmdline.txt
2) Generally,
a) if using sysctl: put a file in /etc/sysctl.d/ containing net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
b) if not using sysctl, add
echo 1 > /proc/sys/net/ipv6/conf/all/disable_ipv6
echo 1 > /proc/sys/net/ipv6/conf/default/disable_ipv6
echo 1 > /proc/sys/net/ipv6/conf/lo/disable_ipv6
to end of (for e.g.) /etc/rc.local
Both methods will disable all ipv6 including link-local
NetworkManager has a "disable" option under ipV6, too.
But dhcp is only used at boot time normally.
What sort of ipv6 addresses ? If it is only link local ipv6
addresses (starting fe80::) then they don't come from DHCPCD but from IPv6 neighbour discovery and are probably quite hard to get rid of but they're only valid on a LAN segment so I wouldn't worry about them too much.
What sort of ipv6 addresses ? If it is only link local ipv6
addresses (starting fe80::)
then they don't come from DHCPCD but from IPv6 neighbour discovery and are probably quite hard to get rid
of but they're only valid on a LAN segment so I wouldn't worry about them
too much.
A new question though (if you don't mind) : I've been trying to disable
ipv6
too, and reading the man page for dhcpcd.conf I saw that I could use
"ipv4only".
Try:
noipv6rs
noipv6
Have you looked at man dhcpcd.conf?
Don't get too hung up on the raspbian/bullseye focus.
dhcpcd configuration is dhcpcd configuration no matter which distro you're using.
It seems there are 2 ways to totally disable ipv6
1) Pi only: add 'ipv6.disable=1' to end of line in /boot/cmdline.txt
Just a small quibble - while the whole /boot/cmfline.txt thing is Pi specific, the ipv6.disable=1 kernel parameter setting should work on all Linux kernels.
So every of those "noipv6" and "ipv4only" things in (man) dhcpcd.config
are fake ? They actually don't do squat ? That would perhaps have been
a good april
a) if using sysctl: put a file in /etc/sysctl.d/ containing net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
So every of those "noipv6" and "ipv4only" things in (man) dhcpcd.config
are fake ? They actually don't do squat ? That would perhaps have been
a good april
Not at all, they control whether or not dhcpcd issues public IPv6
addresses. You get link local addresses without dhcpcd or anything other
than an IPv6 capable kernel.
unlike IPv4 private addresses which are by convention not permitted
to cross routers into the 'public internet'
and have been known to cross boundary routers in both directions.
I'm not sure it's possible to NAT IPv6 link local addresses, you'd
certainly have to work at it,
by default there's no kind of NAT used for IPv6 the addresses are
either link local or public.
Do you happen to know if its possible and if so how to configure ipv6 to /not/ to generate such a "link local address" and only expose an address
if provided thru dhcp (so it functions the same way ipv4 works and its a
per interface thing) ?
Sort of. /Some/ "IPv4 private addresses" may go one way, /others/ may go
the other way. Which ones is under control of and has to be configured
per router.
I'm not sure it's possible to NAT IPv6 link local addresses, you'd certainly have to work at it,
Do you know What would be the difference between ipv4 and ipv6 that would make it especially hard to do for the latter ?
by default there's no kind of NAT used for IPv6 the addresses are
either link local or public.
Thats just because there are way more ipv6 IPs available than we
currently can use, and NAT-ing hem would (look to) be a bit silly - an exercise in futility.
Ahem A Rivet's Shot,
What sort of ipv6 addresses ? If it is only link local ipv6
addresses (starting fe80::) then they don't come from DHCPCD but from IPv6 >> neighbour discovery and are probably quite hard to get rid of but they're
only valid on a LAN segment so I wouldn't worry about them too much.
What sort of ipv6 addresses ? If it is only link local ipv6
addresses (starting fe80::)
it (eth1) is.
then they don't come from DHCPCD but from IPv6 neighbour discovery and are >> probably quite hard to get rid
So every of those "noipv6" and "ipv4only" things in (man) dhcpcd.config are fake ? They actually don't do squat ? That would perhaps have been a good april
first joke, but not on any other day. :-(
of but they're only valid on a LAN segment so I wouldn't worry about them
too much.
:-) All computers on my LAN (and probably yours too) have local ipv4 adresses, but they can still connect to other computers all over the world.
The thing is that that I have multiple computers on my lan, and I don't want to discover that one of them is using ipv6 - which I do not use and as such have very little knowledge of - as a weakpoint to gain access to others.
Regards,
Rudy Wieser
On Wed, 26 Apr 2023 19:14:46 +0100
The Natural Philosopher <tnp@invalid.invalid> wrote:
But dhcp is only used at boot time normally.
Either dhclient or dhcpcd should persist so that it can renew the
lease when the time comes - try a ps -elf | grep dhclient or pgrep -lf dhclient.
Chris,
A new question though (if you don't mind) : I've been trying to disable
ipv6
too, and reading the man page for dhcpcd.conf I saw that I could use
"ipv4only".
Try:
noipv6rs
noipv6
I tried both seperatily and together (even though the latter seems to includ the former), but ifconfig still shows ipv6 adresses. :-\
Have you looked at man dhcpcd.conf?
Thats pretty much the first thing I did after your suggestion to edit that file. Its where I got that "ipv4only" thingy from (which doesn't work as
I imagine it would).
Don't get too hung up on the raspbian/bullseye focus.
dhcpcd configuration is dhcpcd configuration no matter which distro you're >> using.
I've got to take your word for that, as I do not (yet) posess that
knowledge - which is why I mentioned what my starting point is, so we would be on the same page. Thank you for mentioning it.
It seems there are 2 ways to totally disable ipv6
And thanks for those. I think I found those myself too, but didn't
actually
read them as it /looked like/ dhcpcd.conf had the means to gouvern them (and assumed a similar problem as in regard to dhclient - looking at the wrong thing)
But a bit of a bummer : I was assuming that I could disable it for one interface, but keep it enabled for another.
Regards,
Rudy Wieser
On Thu, 27 Apr 2023 09:40:40 +0100, The Natural Philosopher wrote:
I have concluded that like so much software, Mint/Ubuntu/Debian is beingIts also worth remembering that your LAN's firewall router may well have a DHCP router buried in its innards and if this device suffers from bit rot
overwhelmed by the dreaded weed Creeping Featurism and and has been
debugged only insofar as to work for 'normal' situations, and underneath
is a BFM. A Bloody Fucking Mess, that like postscript and X windows has
been stabilised by the general principle of 'buggering around till it
sorta works'.
in the EPROM that holds its firmware and configuration parameters, then
you can get some unpleasant network problems, particularly a problem for those of us still limited to ADSL connections;
**cough** D-Link DSL-320B **cough**
The only source of replacement ADSL routers now appears to be eBay:
I have concluded that like so much software, Mint/Ubuntu/Debian is being overwhelmed by the dreaded weed Creeping Featurism and and has been
debugged only insofar as to work for 'normal' situations, and underneath
is a BFM. A Bloody Fucking Mess, that like postscript and X windows has
been stabilised by the general principle of 'buggering around till it
sorta works'.
It is not DHCPv6 uses the link local addresses for
communication.
They're rather fundamental.
Whereas the link local addresses are protocol level and
their behaviour is built into the IPv6 stack
Thats just because there are way more ipv6 IPs available than we
currently can use, and NAT-ing hem would (look to) be a bit silly - an
exercise in futility.
I rather think there are more than we will ever be able to use.
The Natural Philosopher wrote:
The reality is that there are 32 bits of IPV4 address and 32 bits of
port addresses within that.
16 bits of ports ...
I conclude that in later versions of Mint desktop systems neither
dhclient nor dhcpd are used.
I have found the layer upon layer of obsolete and obsolescent networking >files to be a total pain to deal with.
And indeed even though my server is set to static IP address via
network manager it also has a ghost IP address assigned by DHCP. This >responds to pings and shows up on the router dhcp tables, but is
otherwise completely unused for anything
I have concluded that like so much software, Mint/Ubuntu/Debian is being >overwhelmed by the dreaded weed Creeping Featurism and and has been
debugged only insofar as to work for 'normal' situations, and underneath
is a BFM. A Bloody Fucking Mess, that like postscript and X windows has
been stabilised by the general principle of 'buggering around till it
sorta works'.
The reality is that there are 32 bits of IPV4 address and 32 bits of
port addresses within that.
It is not even sure where Raspian picks up its config files from. These
may belong to obsolete software 'left in place' because no one dared
touch it and the thing works now anyway.
Really?
Consumer routers are mostly utter crap. I have a Draytek now, and it all actually works.
Its got ADSL but Ive migrated to fibre, and id does ethernet WAN as well (like cable)
Chris,
a) if using sysctl: put a file in /etc/sysctl.d/ containing
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
I've applied all three, and after rebooting looking at ifconfig I do not see any ipv6 any more. Thank you.
One question though : The latter two entries seem to be subsets of the first one. Is there something I'm missing or is this just a case of wearing a
belt /and/ suspenders ?
Regards,
Rudy Wieser
Ahem,
It is not DHCPv6 uses the link local addresses for
communication.
I'm still not grasping the distinction between an ipv6 and ipv4 "local address" I'm afraid.
They're rather fundamental.
I've just disabled ipv6 on my RPi and have not noticed anything failing.
IOW, they can't be /that/ fundamental.
Whereas the link local addresses are protocol level and
their behaviour is built into the IPv6 stack
I don't quite get that I'm afraid : If data send and received using such
a link local address can be read by software connecting to the ipv6
stack, what than stops a router to do with as it pleases ?
Or, said otherwise : if the ipv6 stack somehow internally blocks data
send using such a link local address how would a router - or even a
standard 'puter - be able to use that local link address to begin with ?
But further investigation shows that commenting out (or removing)
the above 3 lines and putting just
net.ipv6.conf.eth1.disable_ipv6 = 1
will disable ipv6 on only that interface (eth1)
Note that you must have the interface name correct for it to work.
My problem is that there currently is no fibre available where I live: its ADSL or nothing at present as I'm not keen on WiFi.
I've just disabled ipv6 on my RPi and have not noticed anything
failing. IOW, they can't be /that/ fundamental.
fundamental to IPv6, it won't work without them.
but as long as you have a compliant IPv6 stack then the link local
address will never be used as a source address unless the target is
another link local address
standard 'puter - be able to use that local link address to begin
with ?
The link local address can be used between hosts on the same LAN
segment
On 27/04/2023 13:07, Martin Gregorie wrote:
My problem is that there currently is no fibre available where I live:
its
ADSL or nothing at present as I'm not keen on WiFi.
I have a pretty good Cisco (Linksys rebadged) SOHO ADSL router
Its even got PSTN ports for voip.
Needs a wall wart as I pinched that for the Netgear.
Runs warm in use, but never fails.
If you are in the UK I'll post it
My brain balks about something thats "fundamental to IPv6", but is not an /internal/ IP (like 127.x.x.x) is.
On 27/04/2023 15:04, The Natural Philosopher wrote:
On 27/04/2023 13:07, Martin Gregorie wrote:Oh. I can still buy ADSL routers without WiFi in the UK
My problem is that there currently is no fibre available where I
live: its
ADSL or nothing at present as I'm not keen on WiFi.
I have a pretty good Cisco (Linksys rebadged) SOHO ADSL router
Its even got PSTN ports for voip.
Needs a wall wart as I pinched that for the Netgear.
Runs warm in use, but never fails.
If you are in the UK I'll post it
https://www.broadbandbuyer.com/products/25841-draytek-v2832-k/
Very very good router, that.
On Thu, 27 Apr 2023 10:47:54 +0100, The Natural Philosopher wrote:
Really?Yes, really. The DSL320B I've used for years currently has several
problems:
- its screwing with the fourth term of the IP address,which causes
pinging
other hosts on my LAN to fail - this seems to be corrupting the 4th
term of a fixed IP address
- my DSL320B can currently connect to the outside world from either of
the
two hosts on my LAN, but neither host can talk to the other one.
AFAIK there's no problem with my CAT5/6 switch
- the DSL320B should be configurable via http or telnet, but neither
Firefox nor Lynx shows any ability to access the DSL320B via an http
connection. If I point telnet at it, it accepts the default user name,
'admin', but doesn't accept the password, which also defaults to
'admin'.
- I got a replacement off eBay, because I couldn't find a retailer with
any in stock and its even worse. It won't even accept the default user
name. and can't be pinged.
- The DSL320B manual says you can reset a DSL320B by poking a 'biro'
into a 'reset' hole, but this is a lie: the hole is both too small
and too deeply inset for any biro I've seen to work.
However it should be resettable if you push a toothpick, some 1mm
alloy tube or a shaved down matchstick into the small (1.5mm) 'reset'
hole until you hear the switch click while holding the power switch
down and keeping it pressed 10-15 seconds, but this failed to reset
either of the DSL320Bs.
Consumer routers are mostly utter crap. I have a Draytek now, and itMy problem is that there currently is no fibre available where I live:
all actually works.
Its got ADSL but Ive migrated to fibre, and id does ethernet WAN as
well (like cable)
its ADSL or nothing at present as I'm not keen on WiFi.
I'm currently on the Zen waiting list until fibre connectivity gets
installed (I'm not holding my breath for this) but am about to see if
they Zen can take over my current ADSL link anyway, by installing a
Fritz box, which is what they apparently use as the fibre terminator,
but for use as an ADSL terminator in the meantime.
It sort of is internal - to the LAN not the machine
It's all about scalability really - making it easy to manage a LAN
with tens of thousands of hosts (horrible thought!).
On Thu, 27 Apr 2023 15:24:50 +0200
"R.Wieser" <address@is.invalid> wrote:
My brain balks about something thats "fundamental to IPv6", but is not an
/internal/ IP (like 127.x.x.x) is.
It sort of is internal - to the LAN not the machine, rather like
MAC addresses, the main use is to enable unicast addressing to be used for almost everything and minimise the use of broadcast addressing. It's all about scalability really - making it easy to manage a LAN with tens of thousands of hosts (horrible thought!).
Cellphone data plan connections use IPv6 and need it AFAICT, IPv4
NAT and DHCP would be a nightmare in that environment.
Ahem,
It sort of is internal - to the LAN not the machine
Thats the thing : I do *not* want my machine to just talk to other
machines (on the same lan or not) - at least not without my explicit
say-so.
I regard it as a weakspot, to be exploited when one of those machines on
the LAN gets taken over by malware (and tries to find a way into other machines).
It's all about scalability really - making it easy to manage a LAN with
tens of thousands of hosts (horrible thought!).
All I can think about when I read that is of companies who had to shut
down and had to do a major cleanup because one person got its computer infected and than it spread from there. :-\
On Thu, 27 Apr 2023 12:07:57 -0000 (UTC), Martin Gregorie wrote:
Sorry about the slow reply: I'm bringing up a new server (current AMD silicon, solid state storage) damn quick, and sort of lost track of the
time. The problem it that I was almost too late on making the swap,
because the last backup has a bit of minor file damage: just enoughto make life mire 'interesting' than I wanted. The old dual Athlon box totally
shat on the update I ran after the backup and I thought that the backup
had survived untouched, but it had just enough damage to be annoying.
That aside, Fedora 37 loaded easily, apart fom a bu=it of nonsense from
Brave (crashed immdiately, but today's upgrade fixes that) and the latest Evolution is pretty much a mess on the new box and I've still to migrate PostgreSQL to v 14. On the other hand, Java is up an running without problems, most of my C stuff looks to be OK and Apache is doing its thing pretty well apart from geany needing a reinstall: not yet diagnosed.
My DSL320B ADSL' walwart has a 3.7mm OD coax plug that delivers 12v @
0.5A, so iF that's suitable for your ADSL router I'd be very happy to have it, always assuming enough of its documentation to make it configurable
has survived.
Thanks for the unexpected offer!
Cellphone data plan connections use IPv6 and need it AFAICT, IPv4
NAT and DHCP would be a nightmare in that environment.
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