Re: [opensuse] Linux and multicast
On 10/03/2014 11:24 AM, Hans Walter Finckh wrote:
they should respond the regular ping any ping You give with any parameter coz ping is a TCP/IP based command. if not, you can do it the other way or send a ping from a dhcp-server if there is one
Yes I know they should respond. My question is why only the one device responds to the mulitcast, local broadcast or broadcast addresses. In IPv4, 224.0.0.1 is an address all devices should respond to. Why are they not? -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
James Knott wrote:
On 10/03/2014 11:24 AM, Hans Walter Finckh wrote:
they should respond the regular ping any ping You give with any parameter coz ping is a TCP/IP based command. if not, you can do it the other way or send a ping from a dhcp-server if there is one
Yes I know they should respond. My question is why only the one device responds to the mulitcast, local broadcast or broadcast addresses. In IPv4, 224.0.0.1 is an address all devices should respond to. Why are they not?
Because their interfaces are not set up with that multicast address. -- Per Jessen, Zürich (16.2°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
On 10/03/2014 12:05 PM, Per Jessen wrote:
Yes I know they should respond. My question is why only the one
device responds to the mulitcast, local broadcast or broadcast addresses. In IPv4, 224.0.0.1 is an address all devices should respond to. Why are they not?
Because their interfaces are not set up with that multicast address.
All devices are supposed to listen to that address. It's the all hosts multicast IPv4 address. It's not something you configure. Likewise they should respond to the broadcast (255.255.255.255) and local broadcast (network address plus all ones in the host portion) addresses. https://en.wikipedia.org/wiki/Multicast_address -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
В Fri, 03 Oct 2014 12:22:50 -0400
James Knott
On 10/03/2014 12:05 PM, Per Jessen wrote:
Yes I know they should respond. My question is why only the one
device responds to the mulitcast, local broadcast or broadcast addresses. In IPv4, 224.0.0.1 is an address all devices should respond to. Why are they not?
Because their interfaces are not set up with that multicast address.
All devices are supposed to listen to that address. It's the all hosts multicast IPv4 address. It's not something you configure.
If you know better why ask?
Likewise they should respond to the broadcast (255.255.255.255) and local broadcast (network address plus all ones in the host portion) addresses. https://en.wikipedia.org/wiki/Multicast_address
-- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 10/03/2014 12:29 PM, Andrei Borzenkov wrote:
All devices are supposed to listen to that address. It's the all hosts multicast IPv4 address. It's not something you configure. If you know better why ask?
I'm asking to find out why something that should work doesn't. Why does one Linux device (my A/V receiver) respond, but another Linux device, such as my computers or WiFi access point does not. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
James Knott wrote:
On 10/03/2014 12:29 PM, Andrei Borzenkov wrote:
All devices are supposed to listen to that address. It's the all hosts multicast IPv4 address. It's not something you configure. If you know better why ask?
I'm asking to find out why something that should work doesn't. Why does one Linux device (my A/V receiver) respond, but another Linux device, such as my computers or WiFi access point does not.
The best approach would be to compare their configurations. That they're all Linux is good, but doesn't mean they're all equal :-) -- Per Jessen, Zürich (14.2°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
On 03/10/2014 3:00 PM, Per Jessen wrote:
does one Linux device (my A/V receiver) respond, but another Linux device, such as my computers or WiFi access point does not. The best approach would be to compare their configurations. That
I'm asking to find out why something that should work doesn't. Why they're all Linux is good, but doesn't mean they're all equal:-)
Unfortunately, it's hard to check the config on that A/V receiver or access point. ;-) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
James Knott wrote:
On 10/03/2014 12:05 PM, Per Jessen wrote:
Yes I know they should respond. My question is why only the one
device responds to the mulitcast, local broadcast or broadcast addresses. In IPv4, 224.0.0.1 is an address all devices should respond to. Why are they not?
Because their interfaces are not set up with that multicast address.
All devices are supposed to listen to that address. It's the all hosts multicast IPv4 address. It's not something you configure. Likewise they should respond to the broadcast (255.255.255.255) and local broadcast (network address plus all ones in the host portion)
If I ping the network broadcast address, I don't see anything icmp replies being reported, but I do see them coming in with tcpdump. I presume the firewall is getting in the way. If I ping 255.255.255.255, tcpdump shows nothing. I did play with setting up multicast a few years back, but ISTR it was way more complicated than I needed it to be, and sending multiple packets ended up being sufficiently fast. -- Per Jessen, Zürich (15.8°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
participants (3)
-
Andrei Borzenkov
-
James Knott
-
Per Jessen