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Question : What is base-address.mcast.net ???
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Hello!
I've got the following problem: When i execute "route print" in console i got a message like this:
Network Destination Network Mask Gateway Interface
0.0.0.0 0.0.0.0 172.22.120.9 172.22.121.163
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1
224.0.0.0 240.0.0.0 "local_ip" "local_ip"
But when I ping the address 224.0.0.0 from my local PC it points to another device at the local network. If i ping the address 224.0.0.0 from a server in my network it points to itself like the print of the route command describes ("local_ip" is the ip of the computer that executes 'route print').
Can someone tell me what address base-address.mcast.net is? And why does it point to an other device in the network from our pcs and why not at our servers?
I guess mbase could stand for multicast. But what does it mean in this case?
Thx for any help and Merry Christmas!
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Answer : What is base-address.mcast.net ???
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224.0.0.0 is the address for multicasting, 224.0.0.0/4 is the reserved subnet for multicast traffic.
From RFC1700:
INTERNET MULTICAST ADDRESSES
Host Extensions for IP Multicasting [RFC1112] specifies the
extensions required of a host implementation of the Internet Protocol
(IP) to support multicasting. Current addresses are listed below.
224.0.0.0 Base Address (Reserved) [RFC1112,JBP]
224.0.0.1 All Systems on this Subnet [RFC1112,JBP]
224.0.0.2 All Routers on this Subnet [JBP]
224.0.0.3 Unassigned [JBP]
224.0.0.4 DVMRP Routers [RFC1075,JBP]
224.0.0.5 OSPFIGP OSPFIGP All Routers [RFC1583,JXM1]
224.0.0.6 OSPFIGP OSPFIGP Designated Routers [RFC1583,JXM1]
224.0.0.7 ST Routers [RFC1190,KS14]
224.0.0.8 ST Hosts [RFC1190,KS14]
224.0.0.9 RIP2 Routers [GSM11]
224.0.0.10 IGRP Routers [Dino Farinacci]
224.0.0.11 Mobile-Agents [Bill Simpson]
224.0.0.12-224.0.0.255 Unassigned [JBP]
224.0.1.0 VMTP Managers Group [RFC1045,DRC3]
224.0.1.1 NTP Network Time Protocol [RFC1119,DLM1]
224.0.1.2 SGI-Dogfight [AXC]
224.0.1.3 Rwhod [SXD]
224.0.1.4 VNP [DRC3]
224.0.1.5 Artificial Horizons - Aviator [BXF]
224.0.1.6 NSS - Name Service Server [BXS2]
224.0.1.7 AUDIONEWS - Audio News Multicast [MXF2]
224.0.1.8 SUN NIS+ Information Service [CXM3]
224.0.1.9 MTP Multicast Transport Protocol [SXA]
224.0.1.10 IETF-1-LOW-AUDIO [SC3]
224.0.1.11 IETF-1-AUDIO [SC3]
224.0.1.12 IETF-1-VIDEO [SC3]
224.0.1.13 IETF-2-LOW-AUDIO [SC3]
224.0.1.14 IETF-2-AUDIO [SC3]
224.0.1.15 IETF-2-VIDEO [SC3]
224.0.1.16 MUSIC-SERVICE [Guido van Rossum]
224.0.1.17 SEANET-TELEMETRY [Andrew Maffei]
224.0.1.18 SEANET-IMAGE [Andrew Maffei]
224.0.1.19 MLOADD [Braden]
224.0.1.20 any private experiment [JBP]
224.0.1.21 DVMRP on MOSPF [John Moy]
224.0.1.22 SVRLOC ftp.com>
224.0.1.23 XINGTV
224.0.1.24 microsoft-ds
224.0.1.25 nbc-pro
224.0.1.26 nbc-pfn
224.0.1.27-224.0.1.255 Unassigned [JBP]
224.0.2.1 "rwho" Group (BSD) (unofficial) [JBP]
224.0.2.2 SUN RPC PMAPPROC_CALLIT [BXE1]
224.0.3.000-224.0.3.255 RFE Generic Service [DXS3]
224.0.4.000-224.0.4.255 RFE Individual Conferences [DXS3]
224.0.5.000-224.0.5.127 CDPD Groups [Bob Brenner]
224.0.5.128-224.0.5.255 Unassigned [IANA]
224.0.6.000-224.0.6.127 Cornell ISIS Project [Tim Clark]
224.0.6.128-224.0.6.255 Unassigned [IANA]
224.1.0.0-224.1.255.255 ST Multicast Groups [RFC1190,KS14]
224.2.0.0-224.2.255.255 Multimedia Conference Calls [SC3]
224.252.0.0-224.255.255.255 DIS transient groups [Joel Snyder]
232.0.0.0-232.255.255.255 VMTP transient groups [RFC1045,DRC3]
These addresses are listed in the Domain Name Service under MCAST.NET
and 224.IN-ADDR.ARPA.
Note that when used on an Ethernet or IEEE 802 network, the 23
low-order bits of the IP Multicast address are placed in the low-order
23 bits of the Ethernet or IEEE 802 net multicast address
1.0.94.0.0.0. See the next section on "IANA ETHERNET ADDRESS BLOCK".
From RFC1112:
Host groups are identified by class D IP addresses, i.e., those with
"1110" as their high-order four bits. Class E IP addresses, i.e.,
those with "1111" as their high-order four bits, are reserved for
future addressing modes.
In Internet standard "dotted decimal" notation, host group addresses
range from 224.0.0.0 to 239.255.255.255. The address 224.0.0.0 is
guaranteed not to be assigned to any group, and 224.0.0.1 is assigned
to the permanent group of all IP hosts (including gateways). This is
used to address all multicast hosts on the directly connected
network. There is no multicast address (or any other IP address) for
all hosts on the total Internet. The addresses of other well-known,
permanent groups are to be published in "Assigned Numbers".
Check out either of these RFCs for all the fun details.
http://www.ietf.org/rfc/rfc1112.txt
http://www.ietf.org/rfc/rfc1700.txt
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