[opensuse] Why no IPv4 link local address?
I just tried an experiment to see if a pair of computers, running openSUSE, could connect via IPv4 link local addresses. In Windows, when DHCP fails, it reverts to a link local address in the 169.254.0.0/16 range. This makes it possible to connect two computers with just an Ethernet cable or ad hoc WiFi connection. However, I've found that openSUSE does not do this, though IPv6 link local works. Any idea why reverting to IPv4 link local was not implemented? I'm using the KDE network manager. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
James Knott wrote:
I just tried an experiment to see if a pair of computers, running openSUSE, could connect via IPv4 link local addresses. In Windows, when DHCP fails, it reverts to a link local address in the 169.254.0.0/16 range. This makes it possible to connect two computers with just an Ethernet cable or ad hoc WiFi connection. However, I've found that openSUSE does not do this, though IPv6 link local works. Any idea why reverting to IPv4 link local was not implemented?
It was and is. On 13.2, the LINKLOCAL_INTERFACES setting in /etc/sysconfig/network/config seems to be gone - in previous versions it looked like this: ## Type: string ## Default: "eth*[0-9]|tr*[0-9]|wlan[0-9]|ath[0-9]" # # Automatically add a linklocal route to the matching interfaces. # This string is used in a bash "case" statement, so it may contain # '*', '[', ']' and '|' meta-characters. # LINKLOCAL_INTERFACES="eth*[0-9]|tr*[0-9]|wlan[0-9]|ath[0-9]" For one thing, it would need updating to work with the bizarro interface names, but the equivalent must be present in wicked somewhere. -- Per Jessen, Zürich (5.9°C) http://www.hostsuisse.com/ - dedicated server rental in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
В Fri, 27 Mar 2015 08:11:31 +0100 Per Jessen <per@computer.org> пишет:
James Knott wrote:
I just tried an experiment to see if a pair of computers, running openSUSE, could connect via IPv4 link local addresses. In Windows, when DHCP fails, it reverts to a link local address in the 169.254.0.0/16 range. This makes it possible to connect two computers with just an Ethernet cable or ad hoc WiFi connection. However, I've found that openSUSE does not do this, though IPv6 link local works. Any idea why reverting to IPv4 link local was not implemented?
It was and is.
Not to my knowledge. It was possible to unconditionally configure link local addresses, but I do not think we ever had the same logic "try DHCP and fall back to linklocal if no address is received", unless it was implemented by DHCP clients themselves.
On 13.2, the LINKLOCAL_INTERFACES setting in /etc/sysconfig/network/config seems to be gone - in previous versions it looked like this:
## Type: string ## Default: "eth*[0-9]|tr*[0-9]|wlan[0-9]|ath[0-9]" # # Automatically add a linklocal route to the matching interfaces. # This string is used in a bash "case" statement, so it may contain # '*', '[', ']' and '|' meta-characters. # LINKLOCAL_INTERFACES="eth*[0-9]|tr*[0-9]|wlan[0-9]|ath[0-9]"
This adds route to 169.254.0.0 network. Not linklocal address itself. It executes bor@opensuse:~> sudo ip -4 route add to 169.254.0.0/16 dev wlan0 with the effect bor@opensuse:~> ip r default via 192.168.1.1 dev wlan0 proto static metric 1024 169.254.0.0/16 dev wlan0 scope link 192.168.1.0/24 dev wlan0 proto kernel scope link src 192.168.1.46 bor@opensuse:~> ip a l 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever 2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000 link/ether 00:1d:09:59:85:e1 brd ff:ff:ff:ff:ff:ff 3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000 link/ether 00:1f:3c:9c:47:ba brd ff:ff:ff:ff:ff:ff inet 192.168.1.46/24 brd 192.168.1.255 scope global dynamic wlan0 valid_lft 78376sec preferred_lft 78376sec No link local address as you see. Link local addresses were added by avahi as far as I remember.
For one thing, it would need updating to work with the bizarro
interface
names, but the equivalent must be present in wicked somewhere.
-- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Andrei Borzenkov wrote:
В Fri, 27 Mar 2015 08:11:31 +0100 Per Jessen <per@computer.org> пишет:
James Knott wrote:
I just tried an experiment to see if a pair of computers, running openSUSE, could connect via IPv4 link local addresses. In Windows, when DHCP fails, it reverts to a link local address in the 169.254.0.0/16 range. This makes it possible to connect two computers with just an Ethernet cable or ad hoc WiFi connection. However, I've found that openSUSE does not do this, though IPv6 link local works. Any idea why reverting to IPv4 link local was not implemented?
It was and is.
Not to my knowledge.
You're right, my fault, I misread the config.
Link local addresses were added by avahi as far as I remember.
Hmm, I remember seeing avahi running, yes. I guess that's what James need to look at. -- Per Jessen, Zürich (10.2°C) http://www.dns24.ch/ - free dynamic DNS, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
participants (3)
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Andrei Borzenkov -
James Knott -
Per Jessen