[Info-vax] Trying to read form an ethernet port using NMA$C_PCLI_MCA to filter multicast packets...

[Stephen Hoffman]

On 2015-08-29 04:39:35 +0000, john.weed at triangleexperience.com said:

> Anyone have any good, working examples of reading multicast Ethernet 
> frames using the NMA$C_PCLI_MCA setting?

ps: For an example of using the multicast address knob, see the TCPDUMP 
tool on the old OpenVMS Freeware.

This TCPDUMP port 
<http://www.digiater.nl/openvms/freeware/v60/tcpdump-3_7_2/> is 
ancient, but it contains the requested examples of using the multicast 
address knob.

Look in the PCAP-related PCAP-LAN and PCAP-VCI directories.

The examples are in C and not Bliss that you're currently using, 
obviously.   Bliss examples are... scarce.

$ search {path}[tcpdump...]*.c NMA$C_PCLI_MCA/window=5

******************************
{path}[TCPDUMP.pcap-lan]ssubs.c;1

**      NMA$C_PCLI_EKO -> Echo Mode (NMA$C_STATE_OF
**      NMA$C_PCLI_ILP -> Internal Loopback Mode. (NMA$C_STATE_OF
**     *NMA$C_PCLI_MCA -> Multicast Address (NMA$C_LINMC_SET: 09-00-2B-02-01-0
**      NMA$C_PCLI_MLT -> Multicast Address State (NMA$C_STATE_OF
**     *NMA$C_PCLI_PHA -> Physical Port Address (current/hdwr addres
***************


    *bufwpos++  = NMA$C_PCLI_MCA;       /* Multi-cast Address
    *bufwpos++  = 8;                    /* Counted byte string...
    *bufwpos++  = NMA$C_LINMC_SET;      /* Set the multicast address

******************************
{path}[TCPDUMP.pcap-vci]ssubs.c;1

**      NMA$C_PCLI_EKO -> Echo Mode (NMA$C_STATE_OF
**      NMA$C_PCLI_ILP -> Internal Loopback Mode. (NMA$C_STATE_OF
**     *NMA$C_PCLI_MCA -> Multicast Address (NMA$C_LINMC_SET: 09-00-2B-02-01-0
**      NMA$C_PCLI_MLT -> Multicast Address State (NMA$C_STATE_OF
**     *NMA$C_PCLI_PHA -> Physical Port Address (current/hdwr addres
***************


    *bufwpos++  = NMA$C_PCLI_MCA;       /* Multi-cast Address
    *bufwpos++  = 8;                    /* Counted byte string...
    *bufwpos++  = NMA$C_LINMC_SET;      /* Set the multicast address
$



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