Hello again, see my comments inline Stephen Hemminger wrote: >On Thu, 07 Jul 2005 18:37:07 +0200 >Olaf Menzel <olaf.menzel@xxxxxxxxxxxxxxxxxxx> wrote: > > > >>Hello, >> >>I am experimenting with delivering IPv6 multicast traffic over the >>WRT54GS, running OpenWRT. OpenWrt is currently running linux-2.4.30 for >>the mipsel architecture and the OpenWRT distribution has bridged the 4 >>port LAN switch (vlan0) with the WLAN interface (eth1) by default. On >>the IP layer both devices are represented via the br0 interface. The >>bridge work fine for IPv4 Unicast and Multicast and for IPv6 Unicast but >>not for IPv6 multicast. >> >>I went into a problem with forwarding the MLDv2_report message over the >>bridge from a mobile client, connected over WLAN. The MLDv2 report >>messages are received in in the eth1 (WLAN IF), but not in the eth0 nore >>in the br0 interface. Does the bridge support IPv6 multicast compliant >>MAC addresses, starting with 3333+LowByte(Ipv6 MulticastAddress) ? >> >> > >The bridge handles IEEE multicast mac addresses > For IPv6 Multicast the RFC 2464 (http://www.rfc-editor.org/rfc/rfc2464.txt) describes, how an IPv6 multicast compliant MAC address will be created. I hope this RFC is compatible with the IEEE multicast mac standard. > >(ie. least significant bit of first byte of address is set). >What is a an example Ethernet MAC address of a MLDv2 message? > > a MLD report has the IPv6 link local multicast destination aaddress: FF02::16(all mldv2 router) and will map to 33:33:00:00:00:16, while a MLD query with FF02::1 (all local nodes) has to be mapped to 33:33:00:00:00:01. I will attach the whole Packet tethereal dump: 1. MLDv2 query: Ethernet II, Src: 00:0d:88:fc:c7:6c, Dst: 33:33:00:00:00:01 Destination: 33:33:00:00:00:01 (IPv6-Neighbor-Discovery_00:00:00:01) Source: 00:0d:88:fc:c7:6c (D-Link_fc:c7:6c) Type: IPv6 (0x86dd) Internet Protocol Version 6 Version: 6 Traffic class: 0x00 Flowlabel: 0x00000 Payload length: 36 Next header: IPv6 hop-by-hop option (0x00) Hop limit: 1 Source address: fe80::20d:88ff:fefc:c76c (fe80::20d:88ff:fefc:c76c) Destination address: ff02::1 (ff02::1) Hop-by-hop Option Header Next header: ICMPv6 (0x3a) Length: 0 (8 bytes) Router alert: MLD (4 bytes) PadN: 2 bytes Internet Control Message Protocol v6 Type: 130 (Multicast listener query) Code: 0 Checksum: 0x26de (correct) Maximum response delay[ms]: 2000 Multicast Address: :: S Flag: OFF Robustness: 0 QQI: 0 2. MLDv2 report: Ethernet II, Src: 00:13:10:1f:b1:ad, Dst: 33:33:00:00:00:16 Destination: 33:33:00:00:00:16 (IPv6-Neighbor-Discovery_00:00:00:16) Source: 00:13:10:1f:b1:ad (Cisco-Li_1f:b1:ad) Type: IPv6 (0x86dd) Internet Protocol Version 6 Version: 6 Traffic class: 0x00 Flowlabel: 0x00000 Payload length: 96 Next header: IPv6 hop-by-hop option (0x00) Hop limit: 1 Source address: fe80::213:10ff:fe1f:b1ad (fe80::213:10ff:fe1f:b1ad) Destination address: ff02::16 (ff02::16) Hop-by-hop Option Header Next header: ICMPv6 (0x3a) Length: 0 (8 bytes) Router alert: MLD (4 bytes) PadN: 2 bytes Internet Control Message Protocol v6 Type: 143 (Multicast Listener Report Message v2) Code: 0 (Should always be zero) Checksum: 0xfc03 (correct) Exclude: ff02::d (ff02::d) Mode: Exclude Aux data len: 0 Multicast Address: ff02::d Exclude: ff02::1:ff00:0 (ff02::1:ff00:0) Mode: Exclude Aux data len: 0 Multicast Address: ff02::1:ff00:0 Exclude: ff02::2 (ff02::2) Mode: Exclude Aux data len: 0 Multicast Address: ff02::2 Exclude: ff02::1:ff1f:b1ad (ff02::1:ff1f:b1ad) Mode: Exclude Aux data len: 0 Multicast Address: ff02::1:ff1f:b1ad > > >>Usually a bridge is working on L2 and should forward any ICMPv6 packages >>.? The bridge is forwarding any other IPv6 traffic without problems >>e.g. ICMPv6 messages generated with ping6. MLDv2 report messages are a >>subset of IPv6 ICMP messages with the link local IPv6 multicast address >>FF02::16 ( all MLDv2 compliant router) as destination address. The same >>behavior I figured out with the MLDv2 query messages, sent by the >>Multicast router to all nodes (FF02::1) on the local link. The MLD query >>I have seen at the eth0 IF but not at the wireless link. Any other IPv6 >>link local multicast adresses are forwarded e.g. IPv6 router >>advertisements or neighbour soicitation messages. Do you have any idea, >>how to solve the problem ?? >> >> > >The bridge intentionally knows nothing about higher level protocols. >But if you are using ebtables/iptables perhaps a filtering rule is getting >in the way. > > Olaf
